Author Topic: Russian RadioAstron (Spectr-R) update  (Read 36591 times)

Offline Salo

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Russian RadioAstron (Spectr-R) update
« on: 11/19/2011 08:45 AM »
The home page for the RadioAstron Project
http://www.asc.rssi.ru/radioastron/

Plasma-F experiment
http://www.plasma-f.cosmos.ru/en/node

RadioAstron booklet, ASC 2007
http://www.asc.rssi.ru/radioastron/_files/booklet_en.pdf

Science priorities of the RadioAstron space VLBI mission. N. Kardashev, Glen Langston, AAS 2007
http://www.asc.rssi.ru/radioastron/_files/ra_aas07.pdf

The RadioAstron User Handbook:
http://www.asc.rssi.ru/radioastron/documents/rauh/en/rauh.pdf

Some information about project:
http://www.roscosmos.ru/main.php?id=363
« Last Edit: 11/24/2011 05:38 PM by Salo »

Offline Salo

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Re: Russian Radioastron (Spectr-R) update
« Reply #1 on: 11/19/2011 08:46 AM »
News of the RadioAstron mission

by Larisa Likhacheva, larlikh@asc.rssi.ru
Boris Novikov, nbs@mx.iki.rssi.ru
 
At present all systems and units of the SC "Spectr-R" work in a normal mode.
 
•  August, 23d  -- As well as it has been planned on August, 21st the session in the domain of a perigee (90000 km) between the SC (switching on of a basic transmitter (40 Watts) of the VIRK) and the ground tracking station (TS) has taken place.
Pointing of the VIRK sharp directional antenna to the TS was carried out. The session has passed successfully at regular temperature of the transmitter and normal level of a signal-to-noise ratio (52 dB). The signal was received by the TS at Pushchino.
 
•  August, 18th -- full engagement of the high informational radio channel (VIRK) transmitter has been done. In connection with some features of SC position in the orbit currently the Pushchino tracking station (TS) "has seen" a side lobe of the VIRK directional pattern.  A complete session SC -- Pushchino TS is planned on August 21st
 when the SC is going to be in the domain of the perigee. 
 
Total engagement of VIRK is the  second key event for onboard scientific payload functioning after deployment and fixation of the SRT antenna (July, 23d, 2011)!
 
•  August 13th
– a highly directive antenna pointing of a high informational channel
(VIRK) on the Pushchino TS antenna was  switched on. Within two hours the communication session with Pushchino TS  in mode loop of phase stability (LPS, a phase loop) was proceeded.
 
•  August 12th -- the spacecraft "Spectr-R" has passed a perigee on distance of 4000 km.
 
•  August 4th -- the spacecraft  "Spectr-R" has passed a perigee on distance of 2000 km from the Earth. The receiver and transmitter of PFS (this part of high informational radio channel (VIRK) is responsible for creation of a synchronization phase loop of TS and SC) was successfully switched on.
 
•  July 27th, 2011 -- after passage of shadow and a perigee the onboard H-maser was successfully turned on. 
 
•  July 26th, 2011 -- a procedure of onboard H-maser thermostats switching on preparation was done. 
 
•  July, 25th, 2011-- detenting of a VIRK sharp directional antenna drive is done. 
 
•  July, 23rd, 2011 -- deployment and fixation of the SRT antenna is done. 

http://www.asc.rssi.ru/radioastron/news/news_hot.pdf

Offline Salo

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Re: Russian Radioastron (Spectr-R) update
« Reply #2 on: 11/19/2011 08:47 AM »
News of the RadioAstron mission
by
Larisa Likhacheva, larlikh@asc.rssi.ru
Boris Novikov, nbs@mx.iki.rssi.ru
 
At present all systems and units of the SC "Spectr-R" work in a normal mode.
• Until August, 30th it was impossible to implement completely a highly stable signal of the onboard hydrogen maser due to the absence of synchronization by a signal of the hydrogen generator.
•  August, 31st  -- the command on switching on of  the second  onboard hydrogen maser has been given. The second hydrogen maser was switched on and from that moment it works stable and keeps all the specified parameters.
• At the same day (August 31st) for the functioning checking, all the scientific devices and units of the focal container have been switched on:  the shaper of heterodyne micro-wave frequencies, the micro-wave  signals selector, the block of pulse calibration, the control and analysis block (BUAS-F), four termostats of receivers on 18 and 92 cm. Also the part of instrumentation container devices was switched on. A successful switching on of  the rubidium standard of frequency (two complete sets
RUS01 and RUS02) produced by Neuchatel Observatory (Switzerland) also has been carried out. There are no remarks to the devices operation.

http://www.asc.rssi.ru/radioastron/news/news_hot.pdf
 

Offline Salo

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Re: Russian Radioastron (Spectr-R) update
« Reply #3 on: 11/19/2011 08:47 AM »
RadioAstron Newsletter
Number 5
September 16, 2011

Spectr-R in-orbit tests continue.
Many things have happened since the previous Newsletter which reported on the space radio telescope deployment.

Science payload and survice systems of Spectr-R weresuccessfully turned on. Technical details can be found here:
http://www.asc.rssi.ru/radioastron/news/news.html

In particular:
- The H-maser (atomic clock) was turned on and internal test has shown that the clock works properly, its stability is reported to be within the specs.
- Tests of "VIRK", the system which includes high-gain 1.5-m diameter antennae and is used to contact with the tracking station in Pushchino, continue. The so-called "open loop", the tone signal at 8 GHz, was successfully detected in Pushchino and is being used to perform Doppler measurements of the orbit parameters.

The 15 GHz tone signal was also successfully detected.
- Today, the first system temperature measurements were performed for the Australian-made 18 cm astronomical receiver while the space telescope was pointed on a cold sky;
the system temperature is estimated to be about 42 K which is close to receiver’s specifications.

Plans for the near future:
- VIRK pointing correction measurements and 15 GHz data link tests,
- performance measurements for all the other astronomical receivers of the 92, 6, and 1.3 cm bands,
- Cassiopea A first light single-dish radio astronomical observations including space radio telescope efficiency measurements.

With best regards,
Nikolai Kardashev (nkardash@asc.rssi.ru)
Yuri Kovalev (yyk@asc.rssi.ru)

http://www.asc.rssi.ru/radioastron/newsletter/newsl.pdf

Offline Salo

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Re: Russian Radioastron (Spectr-R) update
« Reply #4 on: 11/19/2011 08:48 AM »
http://www.engineeringnews.co.za/article/south-africa-set-to-join-space-radio-astronomy-programme-2011-09-23

"It is now almost certain that South Africa will soon join the Russian-led international Radioastron space telescope consortium. South Africa is expected to sign the agreement late this month or next month."

"South Africa is expected to use the new 15 m dish at the Hartebeesthoek Radio Astronomy Observatory (HartRAO), west of Pretoria, to participate in Radioastron. The 15 m dish was originally the XDM prototype dish for the Karoo Array Telescope (KAT, now MeerKAT) programme, but has been converted into an operational radio telescope to complement HartRAO’s main instrument, the 26 m dish."

Offline Salo

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Re: Russian Radioastron (Spectr-R) update
« Reply #5 on: 11/19/2011 08:49 AM »
RadioAstron Newsletter
Number 6
September 27, 2011
======================
Russian version of the Newsletter can be found here:
http://www.asc.rssi.ru/radioastron/newsletter/newsl_rus.pdf
Spektr-R radiometers in the all four bands are functional The space radio telescope Spektr-R has on-board receivers covering four bands. First in-orbit receivers’ tests were completed recently. We are happy to report that radiometers in all the bands are functioning properly. Total system temperature values were measured and preliminary values are indicated below. These values are close to the specs and confirm high sensitivity at all the bands. Specifically:
* 92 cm (P) band total system temperature: about 200 K (made in: LNA - India, the rest of the receiver - Russia);
* 18 cm (L) band total system temperature: about 40 K (receiver made in Australia);
* 6 cm (C) band total system temperature: about 70 K (receiver made in Russia);
* 1.3 cm (K) band total system temperature: about 60 K at 22 GHz (made in: LNA - USA, the rest of the receiver - Russia).
The shown data are results of measurements performed in a single circular polarization for each receiver out of two polarization available.
More detailed performance measurements of the receivers and the space radio telescope as well as telescope pointing corrections, etc., at these four frequency bands are planned for the near future.

With best regards,
Nikolai Kardashev (nkardash@asc.rssi.ru)
Yuri Kovalev (yyk@asc.rssi.ru)

http://www.asc.rssi.ru/radioastron/newsletter/newsl.pdf

Offline Salo

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Re: Russian Radioastron (Spectr-R) update
« Reply #6 on: 11/19/2011 09:06 AM »
RadioAstron Newsletter
Number 7
September 29, 2011
======================
Russian version of the Newsletter can be found here:
http://www.asc.rssi.ru/radioastron/newsletter/newsl_rus.pdf
Spectr-R space radio telescope first light!
On September 27, 2011, the first light from Cassiopeia A was detected with the space radio telescope Spektr-R of the Radioastron mission. The telescope scanned across the supernova remnant in two perpendicular directions. Signal in two bands of 92 and 18 cm (two circular polarization per band) was successfully detected in the total power mode. Enjoy the first light picture attached. The following space radio telescope key characteristics were preliminary determined:

92 cm:
effective area is 28 m^2 (pre-launch estimates on the ground: 25 m^2),
Full width at half maximum is 6.1 degrees (pre-launch: 6.1 degrees);

18 cm:
effective area is 46 m^2 (pre-launch estimates on the ground: 40 m^2),
Full width at half maximum is 72 angular minutes (pre-launch: 75’).

Next step -- 6 and 1.3 cm. Stay tuned.

With best regards,
Nikolai Kardashev (nkardash@asc.rssi.ru)
Yuri Kovalev (yyk@asc.rssi.ru)
To subscribe or un-subscribe to the Newsletter, use:
http://asc-lebedev.ru/index2.php?engdep=22

http://www.asc.rssi.ru/radioastron/newsletter/newsl.pdf
« Last Edit: 11/19/2011 09:08 AM by Salo »

Offline Salo

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Re: Russian Radioastron (Spectr-R) update
« Reply #7 on: 11/19/2011 09:06 AM »
Astro Space Center
RadioAstron Newsletter
Number 8
November 3, 2011
======================

Space radio telescope tests in 6 and 1.35 cm bands Many observations of space objects have happened by Spektr-R in October 2011 in 6 and 1.35 cm bands. Cassiopeia A, Moon, Jupiter, as well as the Crab nebulae were observed in a scanning mode of a single radio telescopes. Radio signals from all these objects were successfully detected. The space radio telescope pointing has proven to be very good and stable. Tests at these two bands continue in order to achieve high quality telescope calibration information.

First maser observations by the space radio telescope

First single dish observations of a space object have happened on October 29 and 30 when scientific and telemetry data were transmitted to the ground through the wide band 15 GHz data link between Spektr-R and Pushchino tracking station. This mode of observations and recording is similar to the one which will be used for interferometric experiments. A maser source W3(OH) was observed in the OH (1665 MHz) and H20 (22232 MHz) lines. They correspond to 18 and 1.35 cm RadioAstron bands. The measurememnts have happened at the Spektr-R separation from the Earth by 60 and 200 thousand kilometers.
See attached figure with the spectra produced by the RadioAstron in-orbit checkout team of Astro Space Center.
W3(OH) is located about two kiloparsec away from the Earth in our Galaxy in a proto-stellar region. Radio emission from the object was collected by the 10-m space radio dish, digitized and formatted on-board, sent by the high-gain 1.5-m antenna to the Pushchino tracking station, decoded and recorded on the RadioAstron data recorder at the tracking station. Recorded data were transmitted to Astro Space Center over a dedicated Internet line. Data analysis in Astro Space Center confirmed the maser lines in both bands in left and right circular polarizations at expected frequencies, with expected amplitude and shape. As a result, this experiment has confirmed the full functionality of the space segment of interferometer.
First RadioAstron experiments in a mode of Space-Earth interferometer, so called fringe search, are planned to start in the second half of November 2011.

With best regards,
Nikolai Kardashev (nkardash@asc.rssi.ru)
Yuri Kovalev (yyk@asc.rssi.ru)

http://www.asc.rssi.ru/radioastron/news/news_en.pdf

Offline Salo

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« Last Edit: 11/19/2011 09:33 AM by Salo »

Offline Salo

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Re: Russian Radioastron (Spectr-R) update
« Reply #9 on: 11/19/2011 12:17 PM »
http://www.plasma-f.cosmos.ru/en/content/interplanetary-shock-detected-by-bmsw-on-september-9-2011
Quote
Interplanetary shock detected by BMSW on September 9, 2011
31.10.2011

Interplanetary shock on September 9,  2011 was observed by Spektr-R as well as by SOHO, Wind and ACE spacecraft.

Graphs below show changes of the density and velocity direction as registered by BMSW in sweeping mode (compressed data):

These results as well as more information about BMSW had been presented at the workshop "Structure in the Solar-Wind Plasma", Ann Arbor, MI, USA, October 17-20, 2011.

Offline Salo

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Re: Russian Radioastron (Spectr-R) update
« Reply #10 on: 11/19/2011 12:21 PM »
http://www.plasma-f.cosmos.ru/en/content/plasma-f-three-months-orbit
Quote
Plasma-F: Three months in orbit
18.11.2011

Dr. G.N. Zastenker, leading researcher, IKI RAS

Three months have passed since 'Plasma-F' payload aboard Russian astrophysical satellite SPECTR-R was switched on.

Among various phenomena, having occured during this period (August 08 – November 05), of particular interest was extremely sharp distrubance of solar wind which reached the Earth on September 9, 2011 and was registered by BMSW plasm spectrometer.

Read more
« Last Edit: 11/19/2011 12:27 PM by Salo »

Offline Salo

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Re: Russian Radioastron (Spectr-R) update
« Reply #11 on: 11/24/2011 05:36 PM »
RadioAstron Newsletter Number 9
November 24, 2011

RadioAstron fringe search has started

First fringe search observations of the ground-space interferometer RadioAstron have started on November 15 and 23, 2011. Both sessions have happened successfuly, observations were made on the 18 cm band. Scientific data from the space radio telescope were successfully transmitted to and recorded by the Pushchino tracking station. The observations were supported by the following ground VLBI stations: three 32-m telescopes of the Russian VLBI network Kvazar in Svetloe, Zelenchukskaya, Badary, 70-m radio telescope in Evpatoria (Ukraine), 64-m Usuda (Japan), 100-m Effelsberg (Germany), 100-m GBT (USA). Quick data quality check has confirmed that the data are suitable for the fringe search. The data analysis center in Astro Space Center of Lebedev has started the interferometric fringe search.
The first RadioAstron fringe test on November 15 had been also supported by two EVN telescopes, Metsahovi 14 m (Finland) and Onsala 20 m (Sweden) as a part of the JIVE-led Planetary Radio Interferometry and Doppler Experiment (PRIDE). These PRIDE observations of the Spektr-R tone signal at 8.4 GHz will provide additional Doppler measurements for orbit determination feed into the data correlation process.
The RadioAstron team plans first fringe search experiments at the 6 cm band to happen in December 2011.

First successful distance measurements with a laser ranger

Laser ranging is one of several methods being used to reconstruct the Spektr-R orbit with high accuracy required for a proper functioning of the ground-space radio interferometer.
First successful laser ranging of Spektr-R has happened on November 15, 2011, from 5:30 to 6:30 Moscow time. The ranging was performed by the Observatoire de la Cote d'Azur (Grasse, France) as part of the International Laser Ranging Service. The distance measurements were done continuously during 35 minutes resulting in 875 independent measurements. The distance to the space craft has changed during this period of time from 65 to 70 thousand kilometers. Refelected signal was of a very high quality. The error of measurements is about or less than 10 cm.

Results are available from:
ftp://cddis.gsfc.nasa.gov/slr/data/npt_crd/radioastro/2011/

Pulsar PSR0329+54 and water maser Orion KL

As part of the ongoing in-orbit checkout activities, the brightpulsar PSR0329+54 was observed on November 7 at 316 MHz while the water maser in the Orion KL region -- on November 8, 2011, at 22 GHz. The space radio telescope scientific data were transmitted to the ground using the wide band data link to the Pushschino tracking station. Positive data processing results can be found on the attached plots indicating a good overall performance of the system.

With best regards,
Nikolai Kardashev (nkardash@asc.rssi.ru)
Yuri Kovalev (yyk@asc.rssi.ru)

http://www.asc.rssi.ru/radioastron/news/news_en.pdf

Offline Salo

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Re: Russian RadioAstron (Spectr-R) update
« Reply #12 on: 12/08/2011 09:58 PM »
The RadioAstron Newsletter # 10, December 8, 2011.
http://www.asc.rssi.ru/radioastron/news/news_en.pdf

RadioAstron finds first interference fringes

We are delighted to report a successful detection of the first interference fringes -- a correlated signal on ground-to-space baselines -- by the RadioAstron team at the Astro Space Center of the Lebedev Physical Institure, Russian Academy of Sciences. The fringes were found between the space radio telescope, Spektr-R, and the following ground based radio telescopes: The 32-m Russian "Quasar" antennas at Svetloe, Zelenchukskaya, and Badary of the Institute of Applied Astronomy, Russian Academy of Sciences, the 64-m Ukranian antenna at Evpatoria, the State Space Agency of Ukraine, and the Max-Planck-Institute for Radio Astronomy 100-m antenna at Effelsberg, Germany. The observations of the quasar 0212+735 were made on November 15, 2011 at 18 cm wavelength. The attached picture shows the clear detection of the interference fringes on the baseline between Effelsberg and the space radio telescope on a delay-fringe frequency plot. The quasar 0212+735 was selected as a target by the Radioastron team on the basis of a preliminary determination of its very compact structure and high surface brightness by recent observations using the NRAO Very Long Baseline Array in the U.S.

The successful detection of interference fringes demonstrates the overall excellent status of the complex system and reflects the birth of the new international ground-to-space very long baseline interferometer, RadioAstron.

A search for fringes at other frequency bands and at longer interferometer baselines will continue until the end of January 2012, and will be followed by an "Early Science" program on quasars, AGN, pulsars, and cosmic masers. The Astro Space Center will also continue to perform in-orbit tests together with the Lavochkin Association including an effort to improve the quality of scientific data link from the space radio telescope to the ground through the Pushchino tracking station.

On behalf of the Astro Space Center, we would like to congratulate and thank the Lavochkin Association as well as the many other institutions in Russia, Ukraine, and other countries on their long lasting effort which resulted in this milestone result!

With best regards,
Nikolai Kardashev (nkardash@asc.rssi.ru)
Yuri Kovalev (yyk@asc.rssi.ru)
« Last Edit: 12/08/2011 10:01 PM by Salo »

Offline Salo

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Re: Russian RadioAstron (Spectr-R) update
« Reply #13 on: 12/23/2011 09:37 PM »
RadioAstron Newsletter Number 11
December 23, 2011
http://www.asc.rssi.ru/radioastron/news/news_en.pdf

First interference fringe at 6 cm!

According to the RadioAstron in-orbit checkout plan, first interferometric observations at 6 cm were performed on December 1, 2011.
The target was chosen to be the bright, compact and distant active galaxy BL Lacertae. The correlated interference signal was immidiately found by the Astro Space Center RadioAstron correlator with a high signal-to-noise ration between the space and all ground radio telescopes, namely, Eupatoria (Ukraine), Effelsberg (Germany), Medicina (Italy), Yebes (Spain). See fringe examples in the attachement. The successful detection of interference fringes demonstrates the overall excellent status of the complex system at the 6 cm band and reflects the rediness of RadioAstron to start early science observations.

We are pleased to report that ground-space interference fringes at 18 cm were also found in our experiment on November 23 with all participating telescopes which include the 100-meter GBT (NRAO, USA) and 64-meter Usuda (JAXA, Japan) together with the Russian and Ukranian VLBI stations.

A quick success at both 18 and 6 cm bands allowed teh RadioAstron team to start science observations earlier than planned originally. Five SVLBI observing sessions were performed between December 10 and 14 on the extragalactic target BL Lacertae at 18 and 6 cm. Observations of this active galactic nucleus were done for baseline projections from several to more than 20 Earth diameters. The ground VLBI support was provided by the Quasar network, Eupatoria, Yebes, Medicina, Effelsberg. An extra interest is determined by the fact that BL Lacerta went in December 2011 through a major flaring event in radio. Analysis of these observations should allow for a significant step towards better understanding of physical processes in the core of this galaxy.

Giant pulses from the Crab pulsar

The RadioAstron network of the space and ground telescopes has observed gian pulses from the Crab pulsar on November 15, 2011. This experiment was performed in order to check synchronization accuracy of the space and ground time. The Crab pulsar emits so called giant pulses which are thousand times more luminous than its regular pulses. These giant pulses were successfuly detected at 18 cm at the space (Spektr-R) as well as ground (Quasar network, Eupatoria) radio telescopes. Scientists have successfully cross-identified giant pulses at all these telescopes. They matched with an accuracy about or better than one microsecond. This indicates a high reliability of the time synchronizaton between the space and ground telescopes. See figure of one of gian pulses detected by RadioAstron attached.

With best greeting to the New Year 2012!
Nikolai Kardashev (nkardash@asc.rssi.ru)
Yuri Kovalev (yyk@asc.rssi.ru)

P.S. Astro Space Center is very happy to congratulate academician Nikolai Kardashev with the award of the 2012 Grote Reber Gold Medal for innovative and significant contributions to radio astronomy.
http://www.qvmag.tas.gov.au/?articleID=539

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Re: Russian RadioAstron (Spectr-R) update
« Reply #14 on: 01/28/2012 11:22 AM »

Offline Salo

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Re: Russian RadioAstron (Spectr-R) update
« Reply #15 on: 03/13/2012 02:49 PM »
The first results of Plasma-F experiment (only Russian):
http://www.plasma-f.cosmos.ru/first-results

Offline Salo

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Re: Russian RadioAstron (Spectr-R) update
« Reply #16 on: 03/13/2012 02:51 PM »
http://www.novosti-kosmonavtiki.ru/phpBB2/viewtopic.php?p=899320#899320
Coogle translate:
Quote from: Vladimir  March 01, 2012 19:19
Today, held the second of the planned correction of the orbit. As in the first case (21 February), everything went normally. Time adjustment of the engine was 333 seconds (February 21 - 300 seconds). Total momentum is ~ 3.5 m / s.
  More on yesterday's meeting LOCT scientists reported that they were able to correlate the terrestrial and space observation of January 25. To obtain valid scientific results will take another month. The news, of course, is good, but the rate of  :-\

Medicina VLBI telescope observing calendar:
http://www.ira.inaf.it/Observations/calpar.htm
« Last Edit: 03/13/2012 03:05 PM by Salo »

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Re: Russian RadioAstron (Spectr-R) update
« Reply #17 on: 03/13/2012 03:14 PM »

Offline Salo

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Re: Russian RadioAstron (Spectr-R) update
« Reply #18 on: 03/20/2012 07:11 PM »
The RadioAstron Newsletter # 12, March 20, 2012.
http://www.asc.rssi.ru/radioastron/news/news_en.pdf

Astro Space Center
RadioAstron Newsletter
Number 12
March 20, 2012

First 92 cm RadioAstron interference fringe at the 220,000 km baseline
projection!

On January 25, 2012, RadioAstron has successfully detected the first interferometric signal at 92 cm from individual pulses of the pulsar B0950+08 from the longest distance to the space craft - 300,000 km. Projected interferometer baseline was 220,000 km which provided the
highest ever achieved resolution at this wave length of about 1/1000 arcsecond. The ground VLBI stations which participated in this experiment are Arecibo (USA), Westerbork (the Netherlands), and Effelsberg (Germany). The interference fringes were found between the space radio telescope and all thee ground telescopes. See some result on the two attached figures.

The observed variations of the correlated signal from the pulsar is due to the propagation effects - pulsar emission scintillation on the inhomogeneous interstellar plasma. Such effect is only seen for emission of very compact objects. Thus, astronomers have got a tool to study characteristics of the interstellar medium and the pulsar itself, to localize the pulsar radiation zone in the magnetosphere of the neutron star - either above the polar cap or near the light cylinder. The conducted experiment has both confirmed RadioAstron capabilities at 92 cm and provided first important scientific data in this band. About 10 brightest radio pulsars of our Galaxy are planned to be studied in the RadioAstron early science program.

Tests of the closed-loop mode of Spektr-R synchronization

A test in a special closed-loop mode of Spektr-R synchronization was successfully performed on January 22, 2012. This mode of operation utilizes the ground based maser clock located at the Pushchino tracking station to synchronize the space radio telescope observations through a special up-down phase link at 7.2 and 8.4 GHz. As a result of these observations at 18 cm, an interference fringe was found by the RadioAstron correlator from the quasar 0212+735 at the projected distance of about 16,000 km.

Successful Spektr-R orbit correction

In order to correct the orbit of Spektr-R, two injections were done on February 22 and March 1, 2012, with a total momentum of about 3 m/sec.
The correction was performed successfully. As a result, the perigee of the space craft orbit has increased to about 55,000 km, the ballistic life time of the orbit has increased to 10 years.
The RadioAstron early science program and final steps of the fringe search Regular experiments within the RadioAstron early science program (ESP) have started in February 2012. Hydroxyl and water masers in our Galaxy (W3OH, Orion KL, etc.), the Crab pulsar as well as bright active galactic nuclei were observed since then. These experiments were supported from the ground by more than ten different VLBI stations: the European VLBI Network telescopes including the Russian ones, the Ukrainian Eupatoria, the Japanese Usuda. The international RadioAstron ESP working groups are reducing and analyzing the data together with the Astro Space Center correlator.
The fringe search experiments are finishing. First segments of 1.3 cm observations have failed due to very bad weather conditions on the ground (GBT, Effelsberg). The search for 1.3 cm fringes continues. Additionally, first test experiments with the Australian VLBI network LBA were performed on March 11, 2012, to prepare for science observations with LBA preliminary planned for May.

With best regards,
Nikolai Kardashev (nkardash@asc.rssi.ru)
Yuri Kovalev (yyk@asc.rssi.ru)

Offline Salo Ukr

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Re: Russian RadioAstron (Spectr-R) update
« Reply #19 on: 06/14/2012 01:42 PM »
http://www.asc.rssi.ru/radioastron/news/news_en.pdf

Astro Space Center
RadioAstron Newsletter
Number 13
June 14, 2012
======================

First RadioAstron 1.3 cm fringes!

Along with conducting the RadioAstron Early Science Program, the RadioAstron fringe search team continued interferometric tests at 1.3 cm (K-band) -- the shortest RadioAstron wave length. We are happy to report that the first K-band fringes were successfully detected on a baseline Spektr-R -- Effelsberg (MPIfR, Germany) from the compact quasar 2013+370. Moreover, these observations were organized in a dual-band mode. Simultaneous measurements at 6 cm were carried out on the baseline Spektr-R -- Westerbork (WSRT, the Netherlands). The 6 cm fringes were found on this baseline with delay and rate values which agree to the 1.3 cm results. The attached Figure shows the 6 and 1.3 cm fringes. The baseline projection was 1/4 of the Earth diameter.
This positive result marks the successful end of in-orbit tests of the ground-space radio interferometer RadioAstron.

RadioAstron coherence time

Coherence time in radio interferometry is the maximum time interval for which the interferometric signal can be coherently (without loses) integrated. Sensitivity of interferometric measurements is proportional to the square-root of this value. Typical coherence time of ground-ground very long baseline interferometric experiments is 1 to 15 minutes for centimerter wave lengths; it is determined by characteristics of the turbulent atmosphere, ionosphere, troposphere.
Coherence time analysis is extremely important since it characterizes the overall sensitivity as well as stability of the system, including atomic clock.

We have perfomed an analysis of the RadioAstron coherence time at the shortest wave lengths, 6 and 1.3 cm, using observations from March 15 and May 12, 2012, consequently, on the baseline Spektr-R -- Effelsberg. Results are shown on the Figure attached. The signal-to-noise ratio increases as a square-root of integration time (fringe fitting interval) up to about 10 minutes at 6 cm and up to 2 minutes at 1.3 cm. This first estimate of the coherence time demonstrates high stability of the space element of the RadioAstron interferometer.

RadioAstron International Science Council meeting 2012

The RadioAstron International Science Council (RISC) will meet for several days in Pushchino, Moscow region, starting from June 18, 2012. The main goal of the meeting is to discuss the current status of the mission and plans for organization of future RadioAstron experiments. The meeting will unite representatives of Russian and International institutions including many major radio observatories of the world.

With best regards,
Nikolai Kardashev (nkardash@asc.rssi.ru)
Yuri Kovalev (yyk@asc.rssi.ru)

To subscribe or un-subscribe to the Newsletter, use:
http://asc-lebedev.ru/index2.php?engdep=22
« Last Edit: 06/14/2012 01:48 PM by Salo Ukr »

Offline Salo Ukr

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Re: Russian RadioAstron (Spectr-R) update
« Reply #20 on: 07/05/2012 11:18 PM »
http://www.asc.rssi.ru/radioastron/news/news_en.pdf

Astro Space Center
RadioAstron Newsletter
Number 14
July 5, 2012
======================

First results of the RadioAstron early science program


The RadioAstron early science program has started in February 2012 within the following three main areas: active galactic nuclei, cosmic masers, and pulsars. These activities are being conducted by international early science program working groups coordinated by the Astro Space Center. Some first results are presented below.

First experiment to image an active galaxy 0716+714 was conducted in the middle of March 2012 by RadioAstron together with the European VLBI network including the Russian Kvazar system as well as Evpatoria and Usuda. Despite a low activity phase of the object during these observations, 0716+714 was detected at 6 cm between the space radio telescope (SRT) and many ground telescopes in the array up to 5.2 Earth diameters. Preliminary analysis estimates the size of the core in this blazar to be about or less than 40 microarcseconds (0.2 parsec).
The RadioAstron survey of active galactic nuclei in all frequency bands continues. The record is being set so far by a detection of the active galaxy OJ287 at 6 cm with the SRT and Effelsberg at 7 Earth diameters (see the figure). This detection was achieved at about one order of magnitude higher resolution than the one available to ground-based radio interferometers. A preliminary estimate of brightness for these objects is about or greater than 10^13 K. Results of the survey will help to better understand nature of relativistic jets in active galactic nuclei.

First fringes for the water maser line at 1.35 cm in the star forming region W51 are obtained. W51 is one on the brightest water masers in our Galaxy situated at 5.4 kpc in the Sagittarius spiral arm. Correlated signal between space telescope Spektr-R and the 100-m ground radio telescope in Effelsberg (MPIfR, Germany) was obtained on May 12, 2012.
Projected baseline of the earth-space interferometer was about 1.14 Earth diameters. The angular resolution which is the highest ever achieved for the spectral line observations is about 0.2 milliarcsec.
These observations are aimed on evaluation of the possibility to use masers for studies of the physics and dynamics of associated objects with ultra-high angular resolution. Such observations for the first time provide possibility to measure extremely high brightness temperatures which are the key input for studies of the physics of maser sources in the regions of the star and planet formation, envelopes of evolved stars, accretion discs and outflows around young stellar objects and black holes in galactic nuclei. See the figure attached. Several bright details in the plot correspond to different components of the maser source.

Radio pulses from the Vela pulsar propagate through inhomogeneous interstellar plasma. Pulsar radio waves are distorted, scattered and focused by these inhomogeneities which act like lenses with a size of about one astronomical unit. Near the Earth different scattered rays interfere in a narrow cone with an angle of a few milliarcseconds.
Details of the interference can be studied only with a space-ground interferometer which provides necessary angular resolution. In May 2012 radio emission from the Vela pulsar was recorded by the RadioAstron in conjunction with large radio telescopes in Australia and South Africa: Parkes, Mopra, Hobart, Hartebeesthoek and 70-m NASA DSN antenna in Tidbinbilla. Results of data processing have showed that scattering disk is completely resolved on the baseline of SRT-Tidbinbilla (100,000 km). Detailed study of the scattered image and its evolution in time will allow to determine space structure of the inhomogeneities of the interstellar plasma. In addition to that, important constraints can be imposed on the location and structure of the emission region in the magnetosphere of the Vela pulsar. See figures attached. The SRT-ground interferometric response consists of numerous narrow spikes, reflecting multi-ray propagation due to scattering.


First fringes with the DiFX correlator in MPIfR, Bonn!

The Max-Planck-Institute for Radio Astronomy in Bonn has successfully upgraded the software correlator DiFX to allow for correlation of RadioAstron data. The first fringes were detected with DiFX for the December 1, 2011, RadioAstron-Effelsberg observations of BL Lacerate at 6 cm confirming results by the ASC correlator reported in the RadioAstron Newsletter 11.
See details in:
http://www.mpifr-bonn.mpg.de/public/pr/pr-radioastron2012-en.html


RadioAstron International Science Council meeting 2012

The RadioAstron International Science Council (RISC) met in Pushchino near Moscow, on June 18-20, 2012. Members of the RISC include representatives of Russian and international science institutions and observatories, as well as leading experts in the field, from most of the major radio facilities around the globe. The RISC was very pleased to see the significant progress and success of the RadioAstron mission. In order to optimize the scientific return from RadioAstron, the RISC suggested that following the experimental early science phase which is now in progress, that an Open Skies phase starting in mid 2013 be organized around a limited number of key science projects. A call for expressions of interest from self organized science teams will be issued in August 2012 with a goal of receiving formal proposals by February 1, 2013. Based on suggestions from the RISC, a Program Evaluation Committee (PEC) is also being organized to review proposals. Phil Edwards has agreed to Chair the PEC.


With best regards,
Nikolai Kardashev (nkardash@asc.rssi.ru)
Yuri Kovalev (yyk@asc.rssi.ru)

Offline Salo Ukr

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Re: Russian RadioAstron (Spectr-R) update
« Reply #21 on: 07/10/2012 06:08 PM »

Offline Salo Ukr

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Re: Russian RadioAstron (Spectr-R) update
« Reply #22 on: 07/18/2012 02:08 PM »
Presentattion: First year on orbit! (only Russian :( )

http://www.federalspace.ru/main.php?id=2&nid=19328
« Last Edit: 07/18/2012 02:11 PM by Salo Ukr »

Offline Salo Ukr

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Re: Russian RadioAstron (Spectr-R) update
« Reply #23 on: 07/18/2012 02:14 PM »

Offline Salo Ukr

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Re: Russian RadioAstron (Spectr-R) update
« Reply #24 on: 07/18/2012 02:16 PM »

Offline Salo Ukr

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Re: Russian RadioAstron (Spectr-R) update
« Reply #25 on: 07/19/2012 06:43 AM »
Dear colleagues,

One year ago RadioAstron was launched from Baikonur.
Together we have made a tremendous progress since then, have resolved
many issues and started the science program of the mission.
Thanks to all and congratulations with the one year anniversary!

Yours,
Astro Space Center

Yuri Y. Kovalev <yyk@asc.rssi.ru>

Offline Salo

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Re: Russian RadioAstron (Spectr-R) update
« Reply #26 on: 09/18/2012 11:44 AM »
Astro Space Center
RadioAstron Newsletter
Number 15
September 17, 2012
======================
RadioAstron Announcement of Opportunity - 1
for observations from July 2013 to June 2014 inclusive

The space VLBI mission RadioAstron, led by the Astro Space Center (ASC) of Lebedev Physical Institute, provides a range of specific and unique capabilities for detecting and imaging sources of cosmic radio emission at highest angular resolution. The optimal utilization of these capabilities relies on the construction and execution of a balanced scientific program for the Mission.
The scientific program of the RadioAstron will consist of three major parts: the Early Science Program (ESP), Key Science Program (KSP), and General Observing Time (GOT) projects. The Early Science Program, currently underway and planned to continue through 2012 until the middle of 2013, explores the main scientific capabilities of the RadioAstron observations and paves the way to subsequent engagement in the KSP and GOT programs.
Following the completion of the ESP observations, the RadioAstron KSP will commence in July 2013. The KSP is aimed specifically at bringing the focus on the areas of strongest scientific impact of RadioAstron and ensuring a long-lasting scientific impact of the Mission. The KSP observations within the AO-1 period will be carried out between July 2013 and June 2014 inclusive and will have a shared-risk nature since a number of observing modes have not yet been fully tested by the ASC.

Proposals are now invited for the RadioAstron Key Science Program experiments.
The KSP application is a two-stage process. An initial Letter of Intent (LoI) should be directed to the Mission by 17 October 2012. Each team submitting a LoI is expected to participate in the KSP consortia organization meeting that will be held at the Max-Planck-Institute for Radio Astronomy in Bonn on 3-4 December 2012. Based on the positive feedback from the Mission and discussions with other potential KSP proposers during the December meeting, the resulting KSP consortia are expected to prepare full KSP proposals to be submitted by 1 February 2013 to the Mission and to the respective ground radio telescopes required for the specific observations.

For details, please consult RadioAstron AO-1 related documents available from
http://www.asc.rssi.ru/radioastron/ao-1/ao1.html

With best regards,
Nikolai Kardashev (nkardash@asc.rssi.ru)
Yuri Kovalev (yyk@asc.rssi.ru)

http://www.asc.rssi.ru/radioastron/news/news_en.pdf
« Last Edit: 09/18/2012 11:44 AM by Salo »

Offline Salo

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Re: Russian RadioAstron (Spectr-R) update
« Reply #27 on: 10/11/2012 05:21 AM »
Astro Space Center
RadioAstron Newsletter
Number 16
October 9, 2012
======================
One year has passed since the birth of the Spektr-R 10-meter orbiting radio telescope About one year ago, on September 27, 2011, the space radio telescope Spektr-R has registered the first light from the supernova remnant Cassiopeia A. Congratulations to all involved! We are pleased to note that since than the RadioAstron radio interferometer has proven its stability and operability at all four available wave bands of 92, 18, 6, and 1.3 cm. New science results were obtained within the three main areas of the RadioAstron Early Science program: pulsars, galactic masers, and active galactic nuclei. Interferometric signals were successfully detected for the interferometer baselines up to 20 Earth diameters for pulsar observations and up to 7 Earth diameters for quasars.

First RadioAstron-EVN image of the active galaxy 0716+714!

The international RadioAstron AGN early science program team of researchers has produced the first RadioAstron-EVN image of the rapidly variable active galaxy 0716+714 at 6.2 cm (see Figure). Data of about 24 hours of observations from about 10 largest ground radio telescopes from Europe, Russia, and China together with the 10-meter space Spektr-R were used in the analysis. Correlated emission of 0716+714 was detected up to 5.2 Earth diameters. Apparent parameters of the core were estimated. The jet base width is measured to be about 70 microarcseconds or 0.3 parsec, its brightness temperature - about 2x10^12 K which agrees with the model of incoherent synchrotron emission of relativistic electrons with Doppler boosting. We note that these parameters were measured at an epoch of low activity state of the BL Lacertae object 0716+714.

http://www.asc.rssi.ru/radioastron/news/news_en.pdf

With best regards,
Nikolai Kardashev (nkardash@asc.rssi.ru)
Yuri Kovalev (yyk@asc.rssi.ru)
« Last Edit: 10/11/2012 05:23 AM by Salo »

Offline Salo

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Re: Russian RadioAstron (Spectr-R) update
« Reply #28 on: 10/27/2012 06:05 AM »
Number 17
October 26, 2012
======================

The process to select projects for the open RadioAstron observing time within the AO-1 period (July 2013 - June 2014) has started

From the middle of 2013 RadioAstron will move to the open sky phase of  its science operations. Any scientist in the world can apply for the RadioAstron observing time. RadioAstron proposals will be reviewed by the international RadioAstron program evaluation committee. Applying for time is a three-stage process. An initial Letter of Intent (LoI) should have been directed to the Mission by 17 October 2012. Each team submitting an LoI is expected to participate in the key science program (KSP) consortia organization workshop that will be held at the Max-Planck-Institute for Radio Astronomy in Bonn on 3-4 December 2012.
Based on the positive feedback from the Mission and discussions with other potential KSP proposers during the December meeting, the resulting KSP consortia will prepare full KSP proposals to be submitted by 1 February 2013 to the Mission and to the respective ground radio telescopes required for the specific observations. While submitting an LoI and taking part in the workshop is expected to provide significant  advantages to the teams in preparing their full proposals, this is not a mandatory requirement. Details can be found at http://www.asc.rssi.ru/radioastron/ao-1/ao1.html

We are happy to report that the international community has actively participated in the first phase of the process. We have received 31 Letters of Intent with the total observing time request about 4.5 thousand hours which is about 4 times larger than our estimate of available observing time during the AO-1 period. Some more statistics follows. These LoIs were submitted by about 160 co-authors from 18 countries, about 50 of them plan to participate in the consortia organization workshop in December. The highest number of authors are from Russia (34) being followed by Australia, Germany, and USA (about 20 each). Science areas covered by the LoIs include active galactic nuclei (the highest number of Letters), masers, pulsars, interstellar medium, transients, astrometry, gravity, and cosmology.

With best regards,
Nikolai Kardashev (nkardash@asc.rssi.ru)
Yuri Kovalev (yyk@asc.rssi.ru)

http://www.asc.rssi.ru/radioastron/news/news_en.pdf

Offline Artyom.

Re: Russian RadioAstron (Spectr-R) update
« Reply #29 on: 12/25/2012 03:18 PM »
======================
Astro Space Center
RadioAstron Newsletter
Number 18
December 25, 2012
======================
See the full Russian and English version of the Newsletter attached to
this e-mail (pdf)


RadioAstron Early Science Program continues to deliver interesting
results

The Space VLB interferometer RadioAstron continues to study the
unexplored territory -- observe active galactic nuclei at ultimate
baseline length and angular resolution. Particularly, the interferometer
has successfully detected interference signals from the galactic nuclei
OJ287, BL Lac, 0716+714, 0823+033, 1823+568 at projected baselines 6-11
Earth diameters at 6 and/or 18 cm. The AGN team has also seen
indications of detections at even longer projections, this is currently
under investigation. First successful results were delivered at the
shortest wave length, 1.3 cm, as well. So far between 2.5 and 4.3 Earth
diameters for the galaxies 0716+714, 0748+126 and 1749+096. These
results suggest that AGN cores of many of the above mentioned objects
have apparent brightness temperature about or more than 10^13 K.

Observations of the water maser in Cepheus A within the RadioAstron
early science program resulted in a successful detection. Cepheus A is
located at a distance of about 700 pc from the Sun and contains young
cluster of massive stars and protostars. Maser emission of various
molecules is formed in their vicinities. Bright water maser source
contains numerous maser spots which are organized in clusters associated
with different massive stars. Correlated signal was obtained between
space radio telescope Spektr-R of the RadioAstron project and the 40-m
ground radio telescope in Yebes (Spain) on November 18, 2012. Projected
baseline of the space-ground interferometer was 3.5 Earth diameters
(about 45,000 km) which sets up a record for maser observations and
provides angular resolution up to 60 microarcsec. Preliminary data
analysis shows that the observed correlated signal belongs to a
short-living maser component which emerged as a result of a flare.

RadioAstron Green Bank Earth Station

A contract was signed last week between the AUI/NRAO and Lebedev
Physical Institute to build and operate a RadioAstron Earth Station in
Green Bank, WV, USA, which will track the satellite and collect science
data using the NRAO Green Bank 140ft telescope. Tests to point the
on-board high gain antenna to Green Bank and track it by the 140ft
telescope have started in November 2012 and turned out to be successful.
We hope to get it operational by the northern Spring 2013 in addition to
the actively working station in Pushchino, Moscow region, Russia. This
will allow to increase the total amount of available RadioAstron
observing time by about two. This work is funded by Roscosmos.

RadioAstron Key Science Program workshop

About 50 researchers from many different countries have met in
Max-Planck-Institute for Radio Astronomy (MPIfR) in Bonn on December
3-4, 2012, to present their ideas for the RadioAstron Key Science
Program within the open sky RadioAstron Announcement of Opportunity 1.
Discussed projects have covered active galactic nuclei, masers, pulsars,
interstellar medium, transients, astrometry, gravity, and cosmology. The
next step is the full proposal submission, deadline: February 1, 2013.
We thank once again the MPIfR for the wonderful organization of the
event.


With seasonal greetings!
Nikolai Kardashev (nkardash@asc.rssi.ru)
Yuri Kovalev (yyk@asc.rssi.ru)
"Earth is the cradle of humanity, but one cannot live in a cradle forever." - Konstantin Eduardovich Tsiolkovsky.

Offline Salo

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Re: Russian RadioAstron (Spectr-R) update
« Reply #30 on: 03/07/2013 05:04 AM »
Astro Space Center
RadioAstron Newsletter
Number 19
March 6, 2013
======================

Record breaking results of AGN studies with RadioAstron

RadioAstron AGN survey continues to bring new exciting results. Already many active galactic nuclei are detected at 18 and 6 cm up to the projected baselines of 20 Earth diameters. As expected, results at longest projections are mostly delivered on baselines with the most sensitive ground radio telescopes { E elsberg (Germany), Arecibo and GBT (USA). In the same time, all of the ground radio telescopes participating in the AGN survey routinely result in positive Space VLBI detections with Spektr-R.
Observations of 3C273 in January 2013 have broken the record of angular resolution announced last year by ground based 1.3 mm VLBI observations of 3C279 with APEX, SMA, and SMT. The quasar was detected at 8.1 Earth diameters (7.6 G, fringe spacing 27 arcsec, see Figure 1) by the RadioAstron-GBT interferometer at 1.3 cm.
In the beginning of February 2013 RadioAstron has successfully observed the radio galaxy M87. These 1.3 cm observations were, for the rst time, supported from the ground by the phased VLA. Angular resolution was comparable to the size of a shadow of the super-massive black in the center of M87, as predicted by the theory. The AGN working group is currently reducing the data.

Pulsars at long interferometer baselines and interstellar medium

Several eff ects accompany propagation of radio waves through an inhomogeneous interstellar plasma: angular broadening, temporal smearing, distortions in radio spectrum, and intensity modulation (scintillations). These e ects are due to interference of separate radio rays scattered or focused by random plasma inhomogeneities ("rough lenses"). Modern theoretical treatment of mentioned above scattering e ects predicts very low level of visibility amplitude for distant pulsars at long space-ground baselines of the RadioAstron mission. In contrast to these theoretical predictions strong visibilities were detected in observations of the distant pulsar B0329+54.
The observations were conducted with the GBT 100-m radio telescope of NRAO in Green Bank and RadioAstron space telescope at a frequency of 316 MHz. Distance to the spacecraft was about 275 000 km, and RadioAstron-GBT baseline projection was equal to 150 000 km. Fringe visibility amplitude as a function of fringe rate and delay is shown in Figure 2. For a source without scattering one should expect the presence of an isolated peak in the center of the picture. Instead, there is the presence of the whole ensemble of such peaks, each corresponding to certain combination of scattered rays. The observed structure is slowly varying with time at a scale of about 100 seconds. Thus, obtained results require a revision of our understanding of the structure of the interstellar plasma irregularities, and call for a new interpretation of the scattering of radio waves.

Galactic water masers

Successful detection of interference fringes for the water maser in the high-mass star formation region W3 IRS5 located in the Perseus arm at a distance of 1.83 kpc is reported. Correlated signal was obtained with space radio interferometer baselines between the orbiting 10-meter antenna Spektr-R and the 40-m radio telescope in Yebes (Spain) and 32-m ground radio telescope in Torun (Poland). Observing session was held on 2 February 2013. The long projected baseline length (5.4 Earth diameters, about 69 000 km) at the frequency of the water maser transition (22 GHz) corresponds to an angular resolution of about 40 arcsec. This is equivalent to a linear resolution of 0.074 AU (11 million km) for W3 IRS5. This result represents the highest angular resolution ever obtained in observations of water masers. The observations are part of a RadioAstron campaign to explore the existence of very compact maser structures.

With best regards!
Nikolai Kardashev
Yuri Kovalev

http://www.asc.rssi.ru/radioastron/news/news_en.pdf
« Last Edit: 03/07/2013 05:43 AM by Salo »

Offline Salo

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Re: Russian RadioAstron (Spectr-R) update
« Reply #31 on: 03/22/2013 09:05 AM »
http://link.springer.com/article/10.1134%2FS1063772913030025

Astronomy Reports
March 2013, Volume 57, Issue 3, pp 153-194

“RadioAstron”-A telescope with a size of 300 000 km: Main parameters and first observational results

N. S. Kardashev, V. V. Khartov, V. V. Abramov, V. Yu. Avdeev, A. V. Alakoz,
 Yu. A. Aleksandrov, S. Ananthakrishnan, V. V. Andreyanov, A. S. Andrianov, N. M. Antonov,    … show all 134

The Russian Academy of Sciences and Federal Space Agency, together with the participation of many international organizations, worked toward the launch of the RadioAstron orbiting space observatory with its onboard 10-m reflector radio telescope from the Baikonur cosmodrome on July 18, 2011. Together with some of the largest ground-based radio telescopes and a set of stations for tracking, collecting, and reducing the data obtained, this space radio telescope forms a multi-antenna ground-space radio interferometer with extremely long baselines, making it possible for the first time to study various objects in the Universe with angular resolutions a million times better than is possible with the human eye. The project is targeted at systematic studies of compact radio-emitting sources and their dynamics. Objects to be studied include supermassive black holes, accretion disks, and relativistic jets in active galactic nuclei, stellar-mass black holes, neutron stars and hypothetical quark stars, regions of formation of stars and planetary systems in our and other galaxies, interplanetary and interstellar plasma, and the gravitational field of the Earth. The results of ground-based and inflight tests of the space radio telescope carried out in both autonomous and ground-space interferometric regimes are reported. The derived characteristics are in agreement with the main requirements of the project. The astrophysical science program has begun.

http://link.springer.com/article/10.1134%2FS1063772913030025#page-1

Offline Salo

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Re: Russian RadioAstron (Spectr-R) update
« Reply #32 on: 03/22/2013 09:12 AM »

Offline Salo

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Re: Russian RadioAstron (Spectr-R) update
« Reply #33 on: 04/20/2013 03:54 AM »
Astro Space Center
RadioAstron Newsletter
Number 20
April 19, 2013
======================
[Russian version see attached to this e-mail]


RadioAstron Key Science Program: July 2013 -- June 2014

Thirteen proposals with about 200 Co-Is from 18 countries (Russia, USA, Germany, Australia, Italy, Netherlands, UK, Ukraine, Spain, Japan, South Korea, South Africa, Poland, China, Hungary, Mexico, India, Greece) were submitted in responce to the first RadioAstron Announcement of Opportunity (AO-1) to cover the period July 2013 -- June 2014 of the open RadioAstron Key Science Program
http://www.asc.rssi.ru/radioastron/ao-1/ao1.html
In an effort to make most efficient use of the time-limited satellite resources, the call for proposals had encouraged the formation of Key Science Programs (KSPs) and the mission held a Key Science Program consortia organization meeting in Bonn in early December 2012. The proposal deadline was 8 February 2013. In total, about 1.8 thousand hours were requested. A technical assessment of the proposals was carried out by the mission. All proposal were evaluated by the RadioAstron Program Evaluation Committee (RPEC) which was appointed by the RadioAstron International Science Council (RISC). Results of the evaluation were approved by the RadioAstron project director. RPEC members for AO-1 were Phil Edwards (chair, CSIRO, Australia), Tim Pearson (Caltech, USA), Misha Popov (ASC Lebedev, Russia), Richard Porcas (MPIfR, Germany), Elaine Sadler (U. Sydney, Australia), and Mark Reid (Harvard-Smithsonian CfA, USA). Below we list accepted Key Science Programs which have requested observations with RadioAstron during the AO-1 period in a priority order starting from the highest:

Rank A:
* "Space VLBI Survey of AGN at the Highest Angular Resolutions", PI: Yuri Kovalev (ASC Lebedev, Russia)
* "Studies of Pulsars with RadioAstron", PI: Carl Gwinn (UCSB, USA)
Rank B:
* "The nuclear structure in nearby AGN at 3-500 Schwarzschild radii resolution", PI: Tuomas Savolainen (MPIfR, Germany)
* "Probing the innermost regions of AGN jets and their magnetic fields", PI: James Anderson (MPIfR, Germany)
Rank C:
* "Structure and physics of compact jets in AGN", PI: Manel Perucho (U. Valencia, Spain)
* "Space-VLBI observations of radio-transients", PI: Kirill Sokolovsky (ASC Lebedev and SAI MSU, Russia)
* "Study of the water and hydroxyl maser properties with ultimate angular resolution", PI: Andrey Sobolev (Ural Federal U., Russia)

With best regards!
Nikolai Kardashev (nkardash@asc.rssi.ru)
Yuri Kovalev (yyk@asc.rssi.ru)

http://www.asc.rssi.ru/radioastron/news/news_en.pdf

Offline Star One

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Re: Russian RadioAstron (Spectr-R) update
« Reply #34 on: 04/21/2013 08:23 PM »
Still annoying me this craft gets ignored in the press, I have yet to see it mentioned once in any of the astronomy magazines I read.

Offline baldusi

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Re: Russian RadioAstron (Spectr-R) update
« Reply #35 on: 04/21/2013 10:36 PM »
I see all this technical briefs. But I've not seen a single explanation of its results, or a laymen explanation of why this is so wonderful. And this has potential for extremely catchy titles on ANSA or Reuter's. Put a nice article with a catchy title and this will get around the world very fast. But they seem to lack the most basic PR.

Offline websquid

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Re: Russian RadioAstron (Spectr-R) update
« Reply #36 on: 06/28/2013 09:44 PM »
About 3 months ago I made an interview with one of the project scientists for the german website raumfahrer.net. We talked about the science as well as the project history (especially since the launch, how they got the system to work). If you are interested I could post an english version here. Please some feedback: Do you want to read all this in english?

German version (3 parts):
http://www.raumfahrer.net/news/astronomie/17042013190758.shtml
http://www.raumfahrer.net/news/astronomie/18042013224629.shtml
http://www.raumfahrer.net/news/astronomie/20042013013103.shtml

Offline a_langwich

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Re: Russian RadioAstron (Spectr-R) update
« Reply #37 on: 06/29/2013 08:23 PM »
About 3 months ago I made an interview with one of the project scientists for the german website raumfahrer.net. We talked about the science as well as the project history (especially since the launch, how they got the system to work). If you are interested I could post an english version here. Please some feedback: Do you want to read all this in english?

German version (3 parts):
http://www.raumfahrer.net/news/astronomie/17042013190758.shtml
http://www.raumfahrer.net/news/astronomie/18042013224629.shtml
http://www.raumfahrer.net/news/astronomie/20042013013103.shtml

Sure, or link to an english translation.

Is there just one spacecraft?  How much would it cost I wonder to launch an identical one in a mostly opposing orbit?

Offline baldusi

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Re: Russian RadioAstron (Spectr-R) update
« Reply #38 on: 06/29/2013 09:06 PM »
About 3 months ago I made an interview with one of the project scientists for the german website raumfahrer.net. We talked about the science as well as the project history (especially since the launch, how they got the system to work). If you are interested I could post an english version here. Please some feedback: Do you want to read all this in english?

German version (3 parts):
http://www.raumfahrer.net/news/astronomie/17042013190758.shtml
http://www.raumfahrer.net/news/astronomie/18042013224629.shtml
http://www.raumfahrer.net/news/astronomie/20042013013103.shtml

An English version would be great!

Offline websquid

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Re: Russian RadioAstron (Spectr-R) update
« Reply #39 on: 06/30/2013 12:25 PM »
OK then I prepare it for this forum. Shouldn't last too long ;)

Is there just one spacecraft?  How much would it cost I wonder to launch an identical one in a mostly opposing orbit?
Yes, there is only one satellite. A second similar satellite would cost about 200+ million $ I think, but this is only a personal estimate.

But there will be no second satellite for the RadioAstron as it looks today, the Astro Space Center is already working on the next project Spektr-M/Millimetron. This will be a combined far-infrared/millimeter-wavelength telescope located at L2. So it is in a way a bigger Herschel Telescope (the FIR-instruments will be based on Herschels) and in a way a RadioAstron successor working in smaller wavelengths (0.3mm until 1.8cm ) - this means, the longest Millimetron wavelengths is compatible with the shortest RadioAstron wavelengths. IF the Spektr-R works long enough and IF Spektr-M is in orbit fast enough - launch is currently estimated somewhere about 2020 - interferometry with two satellites would be possible.

Another project using two satellites is currently under development by China. But I only know that this project exists, no details.

Offline websquid

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Re: Russian RadioAstron (Spectr-R) update
« Reply #40 on: 06/30/2013 01:02 PM »
Here it is. Sorry for the long post but you asked for it ;D

RadioAstron - The Interview

Raumfahrer.Net: At first I would like you to tell us a bit about your work. In which field do you work and how did you come to RadioAstron?

Kirill Sokolovsky: In fact I have to jobs. My main job is the work at the ASC LPI - here I work for the RadioAstron project. I am also a part-time software developer at the Sternberg-Astronomy-Insitute of the Moscow State University. Here I work on variable stars. This work has no connection to RadioAstron.

I was a student at the Moscow University and then I started working at ASC to get my diploma (the work was about VLBI - Very Long Baseline Interferometry). At that time they searched people for VLBI, there was the perspective that one day RadioAstron would fly.

RN: At which time did the ASC search people?

KS: That is some time ago. I began 2006 to work there.

RN: That is seven years ago. Did you work on RadioAstron at that time?

KS: I did not work on this project then. I worked with data of earth-based  VLBI observations. When I got my diploma, I went to Bonn(Germany) and started working at the Max-Planck-Institute for Radio Astronomy. (MPIfR) to get my Ph.D. I continued to work on earth-based VLBI. Really incorporated in RadioAstron were I since summer 2011, when I came back to Moscow. Before the satellite started, RadioAstron was mainly work for engineers. As an astronomer, I could not really help until that time. After the launch things got much more interesting for me!

RN: After the launch it lasted some months, until scientific observations started. How did you and the other astronomers at ASC feel, when you got the first useful data?

KS: I would say, we were surprised. And very excited, of course! The turning point, when we realized, that this experiment was a success, was some time after the observation on November 14 in 2011 - the first VLBI test. The 100m-radio telescope in Effelsberg, the three russian 32m-telescopes Svetloe, Zelenchukskaya and Badary and the ukrainian 70m-telescop in Evpatoria did participate in this test.

At first, we did not have working software to do the data reduction. We realized later, that the ASC-Correlator software contained a bug, which can only be discovered when working with moving antennas (like the Spectr-R Satellite in its orbit). In principle we created two simplify correlator softwares from scratch, to detect the interference fringes and to find the bug in the "big" correlator.

Later James Anderson at MPIfR developed for the DiFX software correlator the ability, to work with RadioAstron data as well. DiFX is the de-facto standard for earth-based VLBI data processing. But when we made the first tests, this software was not available.

Also there is to say, that there was a smooth transition from technical tests to scientific observations. The system was in a constant debugging process until summer 2012. Only then we were convinced, that the whole systems works correct and that we can now collect good scientific data.

RN: You mentioned the participation of the MPIfR. What do you think about this and how important is this cooperation?

KS: The cooperation with MPIfR was crucial for the project. At first, they granted us observation time in Effelsberg for RadioAstron tests. The Effelsberg telescope proved itself as one of the most useful telescopes during the tests and later the Early Science Program (ESP, running from february 2012 until june 2013). It is very sensitive, fully steerable and is often used for VLBI. That is why the people there watch every detail necessary for interferometric observations and calibration. And it is located on the same continent as the tracking station in Pushchino near Moscow. Therefore there are long common timeframes for observations with the satellite and the ground telescope.

In addition the MPIfR (especially its director Anton Zensus) supported data analysis and data logistics. The main point was the implementation of RadioAstron-support in DiFX. This was a big deal. It became the most important software for data analysis, at least in our AGN-group (active galactic nuclei) group.

RN: Is DiFX only used in Bonn or also at the ASC?

KS: Most of the "DiFXing" for the RadioAstron AGN survey is done in Moscow. Bonn correlates the imaging experiments, which were performed together with the European VLBI Network (EVN). These produce large amounts of data (around 20  TB per observation) and the MPIfR correlator can handle this easily, which is not really true for us in Moscow.

We do not have DiFX on our supercomputer at ASC (it uses the ASC-made software) and the machines which run DiFX do not have enough power to correlate a complete imaging experiment.

At the moment there is work on a detailed comparison between the results of both correlators. But to make this reasonable, all datasets have to be processed with both softwares.

So far there were three imaging experiments together with the EVN. The first was in March 2012 and is completely processed. The processing of the other two is still under way (the observations were in october 2012 and march 2013).

RN: The first image was published. Do you plan to publish the produced images?

KS: For sure yes!

But at the moment we do not have correlated datasets for the other two experiments and when we have these, it can still last one or two months until the final images are created. That is how things go with VLBI. The data processing is much more complicated and "delicate" as in other fields of astronomy, which I did work on.

But I should add that most of the observations are not done in imaging mode. The aim of such observations is just the detection of interferometric fringes. The amplitude of the fringes can be measured for a range of baselines and this can be compared with a simple model of the source. For example we can assume a gaussian model of the source and measure its size.

This was the way earth-based VLBI was done in the time when there were only few telescopes which could do such observations. The problem with image reduction is that you need to cover the so called uv-plane as good as possible. You need many telescopes with different baselines.

When RadioAstron is far from earth we have the situation that all ground telescopes are in fact at the same place - so no imaging is possible. Instead we almost have an interferometer with only two elements. This means we only can create images, when the satellite is not more than 3-5 earth diameters away. At this baseline we do not have the highest resolution, but we can do imaging. At longer baselines we can only compare the measured visible amplitude with a simple model (for example a gaussian). In this case we only can determine the size and brightness of the source. In addition we can determine roughly the shape (is the object stretched or not?). The more data points we get, the more complex models can be used to describe the object.

RN: You mentioned size and brightness, which can be measured with RadioAstron. Often there is talked about "brightness temperature". What does this mean and how can you measure it?

KS: Brightness temperature is a certain way of radio astronomy to talk about surface brightness, something that is determined in optical astronomy as magnitude per area. In the easiest case brightness temperature is the brightness of the object divided by its size. In addition there is a factor to convert this value in Kelvin.

There is some freedom in the way you determine the "size"  of a source when the real size can not be determined. Instead you have a measured interferometric visibility which you can compare with a model. So a spherical model had a slightly different size than a gaussian model for the same source. But in general the difference is for all possible models only a small factor. 10^14K can always be distinguished from 10^11K without problems, no matter which model is used.

RN: What do this different models mean?

KS: The gaussian model is simply a radio source, which brightness profile follows a gaussian curve. There are two variants of this model: circular and elliptical. The gaussian model was simply chosen because it is simple to calculate with it: The Fourier transform of a gaussian curve is another gaussian curve. And the visibility measured by the interferometer is the Fourier transform of the brightness distribution of the source.

A spherical radio source has a slightly different brightness profile, it follows the surface of a sphere. In both cases this is no physical model of the source, but only a "toy model" which allows us to characterize size and flux density of a source. A source where we see almost no details, but where we already can see, that it is no point source - but a slightly increased point source (a typical situation for interferometry).

RN: How does the ability to measure brightness temperature depend on the baseline?

KS: You need many observations with different baselines. When you consider the low sensitivity of the space radio telescope, a simple model (a point with a certain size) seems to fit for all the baselines, even for the extreme angular resolution RadioAstron can achieve.

From a physical point of view, this bright spot (when observing AGN) is the brightest part of the relativistic jet, where the jet becomes transparent for its own synchrotron radiation. This area is called the VLBI-core, the brightest spot in a many lightyears long jet. But there are concurring ideas, what a VLBI-core really is. In principle there could be other options, not only these transparency-thing.

RN: What are these alternate models?

KS: A reasonable alternative is that a VLBI-core is a collimation shock in the jet. In this model the core would be a certain physical region, not a place were the jet becomes transparent for the observed frequency. There are some more models, but these do not seem to work for radio-loud AGN.

A way to test the "synchrotron transparency" is to determine the size of a VLBI core at different wavelengths. The transparency model predicts that the VLBI core should be bigger for smaller frequencies. The reason is that the jet has an opening angle, you could speak of the jet as a cone. For smaller frequencies the jet becomes transparent in a larger distance to its base.

There were ground based observations on this question, but with RadioAstron we can measure this effect with much higher accuracy. The collimation shock theory in contrast does not predict any difference in size and position at different wavelengths.

RN: Are there already hints which model fits better?

KS: At the moment - no. We are still under way to collect more data.

RN: Do you believe that you can unveil the real nature of VLBI cores?

KS: Yes. We only have one real size measurement - the core of the blazer 0716+714 from the imaging experiment with the EVN. We need more time to determine this for other sources based on the fringe survey. For some sources (for example for BL Lac) we should have enough data, but we need more time to process it. I am very sure that we will solve this question with RadioAstron finally.

RN: Another thing is the interstellar matter (ISM). It was expected that this would scatter radio waves but it seems like this does not happen in the expected way?

KS: Yes! The interstellar scattering is a big thing for RadioAstron. I am not an expiret for this, but as I hear from my colleagues the difference between expected and observed scattering is very huge. The scattering is there but very smaller than expected. It seems in general that the scattering is not as homogenous as expected. This is a reason why it is in total smaller than thought before.

In fact was the expectation of strong scattering a large point of objection before RadioAstron started. There were many very smart people who thought that RadioAstron could not see anything beyond 1-2 earth diameters baseline. With the current orbit we reach up to 25 earth diameters. This means the resolution is convenient for everything one can dream of. The question is - what are the smallest details which we can see despite the interstellar scattering? We already can say that we see much more than some experts expected.

RN: When did you realize this behavior of the ISM?

KS: We are the first who measured this directly with an interferometer with baselines larger than earth! For AGN there were early hints, based on the intra-day variability of sources (fast changes of the flux density caused by scattering) that there size is small. But these estimates are even more model-dependent than the size measurement with VLBI.

RN:  So the scattering itself changes in hours?

KS: Yes! And this is something which we want to study in the next years in detail. A large point of the AGN survey program for the next year is the combination of RadioAstron observations with earth-based measurements of daily flux variation to study the scattering.

RN: This sounds a bit like this behavior is comparable with our atmosphere in visible light - like stars blink. Is this comparison legit?

KS: Yes, this analogy seems to be fully correct. And this immediately leads to the idea, wether it is possible to create something like an optical speckle interferometer  for radio waves?! I can not answer this question. Maybe it is possible, but I do not know enough about this topic to say it for sure.

RN: So we have to wait for more information. You mentioned the following years. At the moment the Early Science Program is running, which will end soon. In july the Key Science Program starts. The ESP had a  strong focus on AGN. Will this be the same in KSP or will other topics get a bigger fraction of observation time?

KS: Emanating from the accepted KSP proposals the most observation time will still be used for AGN. Maser and pulsars will also be observed, but I think their fraction will roughly stay the same. I have an accepted project to study transient radio sources like supernovae or tidal disruption events, but this is an experimental project which was never tried before with space-VLBI. So it is not clear whether something will come out of it. But I think it is worth a try.

RN: Which countries made the most KSP proposals? Russia is for sure leading, but in which other countries is the largest interest in RadioAstron?

KS: Add first I would like to add something to the AGN observations: There will be more imaging experiments for sure. Not just three in one year.  Concerning the origin of the proposals I think that most of them, if not all, come from international groups consisting of scientists from many different countries as co-authors. I know Germany, the USA, Spain, Australia, Poland and Japan and for sure I am forgetting some. Sadly there is not yet official information about the accepted proposals. The RadioAstron Program Evaluation Committee made its decision but some of the proposals depend also on the evaluation from the project committees of single ground telescopes or networks like EVN or VLBA, so there is no final list of KSP projects. It can happen that some of the projects accepted for RadioAstron are rejected by ground telescopes so they can not be  carried out.

RN: Can you estimate how many imaging experiments will be performed in the first KSP period (july 2013 - june 2014)?

KS: The imaging experiments depend the most of the availability of ground telescopes. A chance for these experiments is at each perigee passage of Spektr-R, roughly every 8,5 days. This is under the assumption that the tracking station in Green Bank is then available. It is hard to say how many observations really will be performed. I expect at least ten imaging experiments, maybe more. The KSP observation program is not yet fixed. I think there will be no imaging experiments until september because of severe visibility restrictions in the summer. So for the first two months of the KSP there will only be simple fringe detections for AGN, pulsars and masers, like the most time during the ESP.

RN: When will the tracking stations in Green Bank and South Africa start their work?

KS: The tracking station in Green Bank will start soon. Under consideration of possible delays our current best estimate is that it will be available in september. All papers between USA and Russia are signed, the electronic equipment is currently tested in Pushchino. A potential delay risk is the russian toll, but the work is under way. The control system of the 43m-telescope in Green Bank was tested, so I think it is ready. After the data recording equipment is delivered there will be of course some time needed to install and test it. So the most optimistic guess is july, the more realistic is september.

The south african station seems to be still on the level of official talks and agreements. There is currently no technical work done for it. So I think the south african station needs at least a year, maybe longer, until it works.

Offline websquid

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Re: Russian RadioAstron (Spectr-R) update
« Reply #41 on: 06/30/2013 01:41 PM »
In addition, here the images used in the original article:

Kirill Sokolovsky in the control room of the Effelsberg radio telescope


Artistic depiction of Spektr-R. NOTE: This is not correct, it shows an old design based on the AM-Bus instead of the Navigator-Bus


The first image created using RadioAstron


The 43m-telescope in Green Bank - the new tracking station

Offline baldusi

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Re: Russian RadioAstron (Spectr-R) update
« Reply #42 on: 06/30/2013 03:50 PM »
Congratulations! You have more than a couple of articles of information there. A Reuters article could do wonders to this mission awareness.

Offline websquid

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Re: Russian RadioAstron (Spectr-R) update
« Reply #43 on: 06/30/2013 05:32 PM »
A Reuters article could do wonders to this mission awareness.
Yes, you are right.... I hope that this mission will get some broader coverage when results are released. A paper published in Nature or Science would for sure give a little boost. At the moment there are some papers under preparation about the results of the ESP, so maybe then the Reuters article (or whoever similar) may come...

Talking about the Green Bank Tracking Station, here some news:
The equipment was shipped some days ago to Green Bank. If all goes well it can be installed until july 14. Late july and august are planned for tests, the station is expected to be fully operational in september. Then the  observation time for RadioAstron will roughly double.

Offline websquid

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Re: Russian RadioAstron (Spectr-R) update
« Reply #44 on: 08/07/2013 05:58 PM »
Some short updates...

-The radio telescope "TNA-1500" in Kalyazin (Oblast Tver, Russia), a 64m-dish is now refurbished and able to work as a ground telescope for observations. Tests in single-dish mode were very successful, I expect first interferometric observations in september (initially planned observation in august was cancelled).

-The SFXC-Correlator at JIVE (Joint Institute for VLBI in Europe) was upgraded to be able to work with RadioAstron data. Following the ASC-Correlator at LPI in Moscow and the DiFX-Software developed at MPIfR in Bonn it is the third working correlator. This will further reduce the time needed for data processing.

The first data set used for the tests was the imaging experiment from last october. Technically this was highly interesting - C/K-Band imaging of the quasars 2013+370 and 2037+511, spacecraft position tracking was done with EVN-PRIDE. This means, that 4 telescopes of the EVN did observe the Spektr-R spacecraft and determined it's position using VLBI. This allows an extremely exact measure of the position (error <10cm, while classic orbit reconstruction has errors up to 500m). Better position measurements improves the  quality of the final image.

-The Green Bank Tracking Station (called GBES in official project documents) was successfully tested on august 1. This was the second test - the first test failed, signal decoding was not possible. Looks like there were some twisted cables ;) So as planned, it will be operating in september and largely increase the usable observation time (roughly double).

Offline Salo

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Re: Russian RadioAstron (Spectr-R) update
« Reply #45 on: 08/16/2013 06:07 AM »
http://www.nrao.edu/pr/2013/RadioAstron/

Thursday, August 15, 2013

Contact:

Charles Blue, Public Information Officer
Charlottesville, Virginia
(434) 296-0314
cblue@nrao.edu

Venerable NRAO Telescope Reborn as Earth-based Antenna for Orbiting RadioAstron Satellite
 
The trailblazing 43 Meter (140 Foot) Telescope at the National Radio Astronomy Observatory (NRAO) in Green Bank, W.Va., has been given new life as one of only two Earth stations for the Russian-made RadioAstron satellite, the cornerstone of astronomy's highest-resolution telescope.

RadioAstron is the farthest element of an Earth-to-space spanning radio telescope system. Launched in July 2011, RadioAstron -- when linked to large, ground-based radio telescopes like NRAO's massive Robert C. Byrd Green Bank Telescope (GBT) -- creates a virtual radio telescope that extends up to 220,000 miles (350,000 kilometers) across, which is about the same distance as the Earth to the Moon.

From late July 2013 through early August, engineers and astronomers from the United States and Russia successfully installed sophisticated receiving and signal processing instruments on NRAO's 43 Meter Telescope, which was completed in 1965 and retired from routine astronomical observations in 2001. The telescope has now been transformed into one of only two antennas (the other near Moscow) that can receive and process the scientific data from RadioAstron. The addition of the antenna at Green Bank effectively doubles the spacecraft's scientific capabilities.

"NRAO has built the most capable radio telescopes in the world. After nearly half a century of service, the 43 Meter Telescope is once again proving its innovative design and precision construction have much to offer the astronomical community," said Karen O'Neil, the NRAO site director at Green Bank and project lead for the Green Bank portion of RadioAstron.

"The international scientific community is excited about RadioAstron because of the unique science that it will enable," said Ken Kellermann, a scientist at the NRAO in Charlottesville, Va. "By combining its data with leading ground-based telescopes, we will have an incredibly powerful research tool, which will provide extraordinary angular resolution enabling the study of quasars, cosmic masers, and the interstellar medium in unprecedented detail."

RadioAstron uses the same principles as other radio telescope arrays -- like the Karl G. Jansky Very Large Array (VLA), the Atacama Large Millimeter/submillimeter Array (ALMA), and the Very Long Baseline Array (VLBA) -- in which data from each antenna is combined to effectively form a single telescope. The farther apart the antennas, the higher the resolution the telescope is able to achieve.

As part of its early science program, RadioAstron joined the GBT, VLA, and VLBA to achieve a resolution better than one ten-thousandth of an arcsecond, which is several hundred times better than the Hubble Space Telescope and the highest resolution ever achieved in astronomy. The satellite was more than 70,000 miles (112,654 kilometers) away during that observation.

The sensitive radio receivers aboard the spacecraft were fabricated in Russia, India, and Australia. They include two very low noise amplifiers developed at the NRAO's Central Development Laboratory in Charlottesville, Va.

"The RadioAstron early science program, which has just finished, has already brought many surprises to scientists studying quasars, pulsars, and interstellar medium. We expect even more exciting outcomes from our just-beginning key science program," said Yuri Kovalev, the RadioAstron project scientist from the Lebedev Physical Institute of the Russian Academy of Sciences.

Funds to develop and operate the 43 meter antenna as part of the RadioAstron mission are provided by the Russian Federal Space Agency.

The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

###

Image Caption 1: NRAO's 43 Meter Telescope has been transformed into the Green Bank antenna of the RadioAstron project.
Credit: NRAO/AUI/NSF.

Image Caption 2: Artist rendering of the orbiting RadioAstron satellite, the farthest element in an array of radio antennas that combine to form the highest resolution instrument in all of astronomy.
Credit: Lavochkin Assocition.

Image Caption 3: New equipment (a feed horn), being installed on the 43 meter antenna at Green Bank during its recent upgrade for RadioAstron.
Credit: Galen Watts; NRAO/AUI/NSF.


Offline Salo

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Re: Russian RadioAstron (Spectr-R) update
« Reply #46 on: 08/16/2013 06:10 AM »
Astro Space Center
RadioAstron Newsletter
Number 21
August 15, 2013
======================

Green Bank Earth station (GBES)

A group of engineers from Astro Space Center has visited the National Radio Astronomy Observatory, Green Bank, to work together with local NRAO staff on the installation of the tracking station equipment. The instrumentation which has been installed on the 140-ft telescope was manufactured in Russia and is similar to that which has been in operation now for two years at Puschino.  We are happy to report that the equipment was delivered to Green Bank and installed and tested without problems and is now operational. The tests of the GBES went very well.  On 1 August 2013, science data from the RadioAstron space radio telescope was successfully recorded and sent to Moscow for evaluation. Due to the high gain of the 140-ft antenna, the detected signal power level was found to be well above operational requirements, and the bit error rate satisfactorily low.  The results of Doppler measurements of the satellite velocity agreed well with measurements made sequentially by the Green Bank and Pushchino stations.

Active observations of the RadioAstron AO1 Key Science Program will start in late August 2013 with a reduced duty cycle in order to fully develop a detailed operating model.  Starting in early October, we expect RadioAstron scientific observations to be fully supported by the GBES.

We congratulate everyone involved in this achievement, thank the RAO-GB staff for their traditionally very high level of support and wish all of us happy observing with two available RadioAstron tracking stations during the execution of AO1.

The NRAO press release can be found here:
http://www.nrao.edu/pr/2013/RadioAstron/

Nikolai Kardashev (nkardash@asc.rssi.ru)
Yuri Kovalev (yyk@asc.rssi.ru)
« Last Edit: 09/13/2014 04:14 PM by Salo »

Offline Salo

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Re: Russian RadioAstron (Spectr-R) update
« Reply #47 on: 08/16/2013 09:20 AM »

Offline Salo

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Re: Russian RadioAstron (Spectr-R) update
« Reply #48 on: 11/18/2013 04:21 PM »
Astro Space Center
RadioAstron Newsletter
Number 22
November 18, 2013
======================
100 revolutions around Earth!

We would like to thank Russian and international RadioAstron partners, scientists and engineers for their hard work on the occasion of Spektr-R completing 100 revolutions around the Earth since the launch of the space telescope! The spacecraft continues the key science program which started in mid-2013. Most of the teams have already performed the rst experiments within their accepted proposals. In particular, for the rst time space VLBI fringes were detected at 92 cm from an active galactic nucleus (AGN). See the Figure for details. This opens new opportunities in both studying synchrotron self-absorption in jet regions in AGNs and using AGNs at long radio wave lengths for reconstructing parameters of interstellar medium in our galaxy.
The Green Bank Earth station started active operations in September 2013. As a result, the overall accessible RadioAstron observing time has increased substantially, and the accuracy of the RadioAstron orbit reconstruction has improved very signi cantly. Both tracking stations, in Pushchino and Green Bank, continue to operate very reliably.

AO-2 plans

The Announcement of Opportunity 2 for RadioAstron observations in the period July 2014 {June 2015 is expected to be released in early December 2013. The AO-2 proposal deadline will be 27 January 2014. Proposals will be invited for both key science programs and general observing time.

One more software correlator becomes RadioAstron-friendly

The EVN Data processor at JIVE, also known as the JIVE SFXC correlator, has successfully received fringes in a number of RadioAstron data sets at 1.6, 5 and 22 GHz, including spectral line fringes at the latter frequency. For additional details see EVN Newsletter 36 http://www3.mpifr-bonn.mpg.de/div/vlbi/newsletter/36/
It is expected that a part of the upcoming RadioAstron-EVN observations within the AO-1 and AO-2 cycles will be correlated at JIVE.

The COSPAR 40th science assembly

The COSPAR 40th science assembly will be held in Moscow in early August 2014. One of the science events, E1.10, will be devoted to present and discuss RadioAstron results. Details of the meeting will be available soon from the conference web site. Everyone is invited.
https://www.cospar-assembly.org/ & http://cospar2014moscow.com/

Nikolai Kardashev (nkardash@asc.rssi.ru)
Yuri Kovalev (yyk@asc.rssi.ru)
« Last Edit: 09/13/2014 04:15 PM by Salo »

Offline websquid

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Re: Russian RadioAstron (Spectr-R) update
« Reply #49 on: 12/24/2013 07:23 PM »
Planning the future of RadioAstron 8)
http://www.asc.rssi.ru/radioastron/ao-2/ao2.html
Quote
RadioAstron Announcement of Opportunity - 2

The space VLBI Mission RadioAstron, led by the Astro Space Center (ASC)
of Lebedev Physical Institute, provides a range of specific and unique
capabilities for detecting and imaging sources of cosmic radio emission
at the highest angular resolution. The optimal utilization of these
capabilities relies on the construction and execution of a balanced
scientific program for the Mission. The scientific program of
RadioAstron consists of three major parts: the Early Science Program
(ESP), Key Science Program (KSP), and General Observing Time (GOT)
projects. The Early Science Program, which finished in June 2013,
explored the main scientific capabilities of RadioAstron observations
and paved the way for the subsequent KSP and GOT programs.

RadioAstron KSP observations commenced in July 2013. The KSP is aimed
specifically at focusing on the areas of strongest scientific impact of
RadioAstron and ensuring a long-lasting scientific impact for the
Mission. KSP observations within the AO-1 period are being carried out
between July 2013 and June 2014, inclusive.
Looks like all goes well and they do their work. Hopefully it does not last to long until real scientific papers are released... (but recall, VLBI-papers are called "fast" when they are published 2 years after observation... so just be patient)
« Last Edit: 12/24/2013 07:27 PM by websquid »

Offline Artyom.

Re: Russian RadioAstron (Spectr-R) update
« Reply #50 on: 02/12/2014 12:17 PM »
Spektr-R: officially amazing

We are happy to share with you the news that one of many records achieved within the RadioAstron Space VLBI project — the 10-m diameter space radio telescope Spektr-R — has entered the Guinness book.

See the attached copy of the Guinness certificate.

"Earth is the cradle of humanity, but one cannot live in a cradle forever." - Konstantin Eduardovich Tsiolkovsky.

Offline Salo

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Re: Russian RadioAstron (Spectr-R) update
« Reply #51 on: 06/11/2014 07:28 PM »
http://www.asc.rssi.ru/radioastron/news/news_en.pdf

Astro Space Center
RadioAstron Newsletter
Number 24
6 June 2014
======================
The RadioAstron AO-2 open science program starts in July 2014 The rst year of the RadioAstron open science program AO-1 is coming to its end in June 2014.
Astro Space Center and its Russian and international partners have successfuly performed science experiments within all approved AO-1 projects (see the list of projects in the RadioAstron Newsletter No. 20). First results of the AO-1 program will be presented by science teams at the COSPAR-2014 General Assembly in Moscow on 7 and 8 August 2014, see the program of the event: https://www.cospar-assembly.org/admin/session_cospar.php?session=430
Starting from July 2014, the RadioAstron mission will move into the second year of its open program, AO-2 observations will continue until June 2015. The second RadioAstron Announcement of Opportunity has invited proposals of the following two types: the \Key Science Program" (KSP) and \General Observing Time" (GOT). See for details the full set of announcement documents in  http://www.asc.rssi.ru/radioastron/ao-2/ao2.html.
All proposal were evaluated by the RadioAstron Program Evaluation Committee (RPEC) whichwas appointed by the RadioAstron International Science Council (RISC). Results of the evaluation were approved by the RadioAstron project director. RPEC members for AO-2 were Dave Jauncey (CSIRO, Australia), Tim Pearson (Caltech, USA), Misha Popov (ASC Lebedev, Russia), Richard Porcas (chair, MPIfR, Germany), Elaine Sadler (U. Sydney, Australia), and Mark Reid (Harvard-Smithsonian CfA, USA). Below we list 16 accepted projects which have requested observations with RadioAstron during the AO-2 period in their submission order:
 KSP: \Substructure in Pulsar Scattering Disks", PI: Carl Gwinn (UCSB, USA);
 GOT: \Zooming into the high-redshift Universe", PI: Leonid Gurvits (JIVE, the Netherlands);
 GOT: \Space VLBI study of the inner region of the BL Lac source Markarian 501", PI: Gabriele Giovannini (IRA INAF, Italy);
 GOT: \Crab Pulsar Giant Pulse Study with RadioAstron", PI: Alexey Rudnitskiy (ASC Lebedev, Russia);
 GOT: \RadioAstron-VLBI observations: Study of Local Scattering Material", PI: Tatiana Smirnova (PRAO ASC Lebedev, Russia);
 GOT: \Substructure in the Scattering Disk of SgrA*", Michael Johnson (Harvard-Smithsonian Center for Astrophysics, USA);
 GOT: \Imaging of micro-structures of OH and H2O masers with ultimate angular resolution", PI: Hiroshi Imai (Kagoshima University, Japan);
 GOT: \RadioAstron Orbital Precession Imaging of Young AGN Jets", PI: Matthew Lister (Purdue University, USA);
 KSP: \Probing the innermost regions of AGN jets and their magnetic elds", PI: Andrei Lobanov (MPIfR, Germany);
 GOT: \Structure and physics of compact jets in AGN", PI: Manel Perucho (Valencia University, Spain);
  KSP: \Space VLBI Survey of AGN at the Highest Angular Resolutions", PI: Yuri Kovalev (ASC Lebedev, Russia);
 GOT: \Search for new water and hydroxyl maser sources with spots of ultra-small angular size", PI: Andrey Sobolev (Ural Federal University, Russia);
 KSP: \RadioAstron hydrogen maser gravitational redshift experiment", PI: Valentin Rudenko (Lomonosov Moscow State University, Russia);
 GOT: \Space-VLBI investigation of the core shift e ect in the blazar 3C 454.3", PI: Kirill Sokolovsky (ASC Lebedev, Russia);
 GOT: \H2O Masers and Protoplanetary Disk Dynamics in IC 1396N", PI: Stan Kurtz (National Mexico University, Mexico);
 GOT: \Fine-structure of the radio cores in 3C 273 and 3C 279 at ultra-high resolution", PI: Tuomas Savolainen (Aalto University, Finland).
Following recommendations of the RPEC, the RadioAstron mission also plans to organize rst test observations of microquasars (PI: Evgeniya Kravchenko, ASC Lebedev).
Among the approved projects, two got rank `A' (the highest priority), eight | rank `B', and six | rank `C'. A total of about 170 co-investigators represent 20 countries. The largest number of co-Is are from Russia, other countries with a high number of co-investigators are the USA, Germany, Australia, the Netherlands, Spain, UK, Italy.

Nikolai Kardashev (nkardash@asc.rssi.ru)
Yuri Kovalev (yyk@asc.rssi.ru)
« Last Edit: 09/13/2014 04:15 PM by Salo »

Offline Salo

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Re: Russian RadioAstron (Spectr-R) update
« Reply #52 on: 09/13/2014 07:22 AM »
http://www.asc.rssi.ru/radioastron/news/news_en.pdf

Astro Space Center
RadioAstron Newsletter
Number 25
12 September 2014
======================
First space-VLBI polarization images with RadioAstron

The RadioAstron Key Science Program on olarization has succeeded in producing the first space-VLBI polarization images from observations of the high-redshift quasar 0642+449 and BL Lacertae.
The RadioAstron observation of 0642+449 was made on March 9-10, 2013 at a wavelength  = 18 cm, with participation of the European VLBI Network (EVN) including the Russian Quasar network and the telescopes in Evpatoria and Green Bank (GBT). The correlated signal between the ground telescopes and the 10-m space radio telescope (SRT) of RadioAstron has been detected on projected baselines of up to 5.9 Earth diameters in length, achieving a resolution of 0.8 mas at the respective fringe-spacing of 420M. A hybrid image of 0642+449 made from the RadioAstron data is shown in Figure 1.
Observations of BL Lac with RadioAstron were performed on November 11, 2013 at 1.3 cm, with an array of ground antennas that includes the European VLBI Network and NRAO's VLBA, adding for a total of 16 antennas. Correlated visibilities between the ground and space antenna have been found up to a projected baseline distance of 6 Earth diameters, yielding a maximum angular resolution of 33 as, the highest achieved to date. Images of BL Lac with RadioAstron are shown in Figure 2, revealing a twisted structure within the innermost 0.2 mas (0.25 parsec) consisting of two components with orthogonal linear polarization.
Both experiments were correlated by the DiFX correlator in Max Planck Institute for Radio Astronomy in Bonn. The estimated instrumental polarization (D-terms) of the space antenna are found to be within 10% at both observed wavelengths of 18 and 1.3 cm, which confirms excellent polarization performance of the SRT. Results from these experiments will be used for further development of RadioAstron polarization imaging.
These observations, recently reported at the COSPAR-2014 assembly in Moscow, represent a milestone in polarimetric space-VLBI observations. They demonstrate the unprecedented polarization and high angular resolution capabilities of the RadioAstron mission. These and continued observations as part of the RadioAstron Polarization Key Science Program are aimed to obtain a better understanding of the innermost regions of AGN jets and their magnetic field structure.

Nikolai Kardashev (nkardash@asc.rssi.ru)
Yuri Kovalev (yyk@asc.rssi.ru)
« Last Edit: 09/13/2014 04:16 PM by Salo »

Offline Salo

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Re: Russian RadioAstron (Spectr-R) update
« Reply #53 on: 09/20/2014 03:42 AM »
http://www.asc.rssi.ru/radioastron/news/news_en.pdf

Astro Space Center
RadioAstron Newsletter
Number 26
19 September 2014
======================
Nearby pulsars B0950+08 and B1919+21

RadioAstron detected a space-Earth interferometric response of individual radio pulses from the pulsar B0950+08 in one of its first experiments. The observations took place on 25 January 2012, in the 92-cm wavelength band, at a maximum distance to the space radio telescope of 300,000 km. The projected interferometer baseline was 220,000 km, providing a record angular resolution of 1/1000 of arcsecond at this wavelength. The space-ground arms of the interferometer were formed by the largest radio telescopes on Earth, at Arecibo (USA), Westerbork (Netherlands) and Effelsberg (Germany).
From data processing and analysis by the original method of structure functions, the observations produced information on the distribution of interstellar plasma. The modulation index of scintillation was found to be about 40%. Theoretical work has shown that such a modulation can be caused by plasma along the line of sight, in the form of two scattering layers and a "cosmic prism." This "prism" is a quite sharp transverse gradient in the plasma distribution.
It deflects radio emission from the pulsar by 1.1 to 4.4 milliarcseconds. The far scattering layer is most likely on the outer boundary of the Local Bubble (a region of low-density gas in neighborhood of the solar system) at a distance of 26 to 170 pc. The near scattering layer is ionized gas at the border of a local molecular cloud, at a distance of 4.4 to 16.4 pc. The spectrum of turbulent density fluctuations in both layers follows a power-law with index  γ1=γ2= 3.00 +- 0.08. This is signi cantly different from the Kolmogorov spectrum, with  γ= 11/3.
These results could be obtained by Space VLBI observations only, because the Fresnel zone of the observed refraction is greater than the diameter of the Earth. The results of this study are published in the Astrophysical Journal (T.V. Smirnova, V.I. Shishov, M.V. Popov, C.R. Gwinn et al., 2014, ApJ, 786, 115): http://dx.doi.org/10.1088/0004-637X/786/2/115 .
Similar results were obtained recently for another nearby pulsar, B1919+21. The interstellar scintillation of PSR B1919+21 is also defined by two screens of plasma inhomogeneities. Two components of scintillation consist of strong diffractive scintillation from a screen located at a distance of 300 pc, and weak scintillation at the layer at a distance 0.7 pc from the Earth. Angular refraction by a cosmic prism located on the distance of 1.7 pc defines the frequency structure of the scintillation. The refractive angle of this prism is 110 mas. The cosmic interferometer resulting from scattering resolves the scattering disk, with size of θdiff =1.5 mas.

Scattering disc substructure in the pulsar B0329+54

The high angular resolution offered by the RadioAstron space-ground interferometer provided the possibility to measure the size of the scattering disk and to estimate the position of the effective scattering screen for the pulsar B0329+54, at an observing frequency of 324 MHz. Observations were conducted in two separate periods: in November 2012 and in January 2014. Observations were supported by the Green Bank Telescope (USA), the Westerbork Synthesis Radio Telescope (the Netherlands), and the 64-m radio telescope at Kalyazin (Russia). Thespace-ground baseline projections varied from 60,000 to 235,000 kilometers during the November 2012 session, and from 15,000 to 120,000 kilometers in January 2014.
Notable visibility amplitudes were detected even at the longest baseline projections of more than 200,000 km, with a values of about 5%, at a 20-σ significance level. The visibility function at the longest spaceround baselines in the delay domain consists of many isolated unresolved spikes. The overall spread of such spikes corresponds to a temporal broadening with a fullwidth at half-maximum of about 7.5 μs. The fine structure of the visibility function in delay is consistent with an amplitude-modulated noise model, and so supports a theoretical picture of randomly scattered rays.
At short space-ground baselines, the distribution of peaks contains a strong central peak. The amplitude of a central peak decreases with the baseline, providing a direct measurement of the size of the scattering disk. This size was found to be 4.6 mas. By comparison of temporal and angular broadening we estimated a distance to the effective scattering screen, and found that it is located nearly halfway to the pulsar. Figure 1 shows the evolution of visibility structure with increasing baseline projection: at short baselines there is a central peak and an extended component; the amplitude of the central peak decreases with the increasing baseline; and only the extended component is present at the longest baselines.

Nikolai Kardashev (nkardash@asc.rssi.ru)
Yuri Kovalev (yyk@asc.rssi.ru)
« Last Edit: 09/20/2014 03:54 AM by Salo »

Offline Salo

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Re: Russian RadioAstron (Spectr-R) update
« Reply #54 on: 04/01/2015 04:54 AM »
http://www.asc.rssi.ru/radioastron/news/news_en.pdf

======================
Astro Space Center
RadioAstron Newsletter
Number 27
31 March 2015
======================
RadioAstron study of galactic and extragalactic water masers

First space-ground detection of extragalactic megamaser: NGC4258 RadioAstron has detected water maser emission from the circumnuclear disk of NGC 4258 galaxy. NGC 4258 (also known as Messier 106) is a spiral galaxy (Seyfert II type) located at the distance of 7.6 Mpc in the constellation Canes Venatici. The H2O Megamaser NGC 4258 is a prototype object with maser spots tracing the accretion disk around a supermassive black hole. The pumping is provided by the in uence of X-ray emission from the center of the galaxy on the disk material. The existence of multiple components is explained by turbulence and
instabilities in the disk. Interferometric signals were obtained with the space radio telescope (SRT) Spektr-R of the RadioAstron project and two ground facilities, the 100-m radio telescope in Green-Bank (USA) and the 32-m radio telescope in Torun (Poland) on 18 December 2014 (Figure 1). The spectrum in the figure shows a 30 minute integration. The extremely small spread among the fringe phases with velocity shows how remarkably thin the actual distribution of masers in the accretion disk is.
The projected baseline length was up to 2 Earth diameters, corresponding to a fringe spacing of about 110 μas. This first extragalactic detection suggests that H2O Megamasers can be successfully studied with RadioAstron and that high resolution SVLBI imaging of H2O Megamasers is possible leading to a detailed analysis of circumnuclear disks in other galaxies.

Water masers in star-forming regions of our Galaxy: Orion KL, W49 N, W3 (H2O)

Successful detection of interferometric fringes from very compact water maser feature associated with the nearest and well studied high-mass star-forming region Orion KL within the RadioAstron key science maser program is reported. Orion KL is a part of the Orion Nebular Cloud Complex and is located around 420 pc from the Sun. Active star formation occurs in this source, accompanied by a powerful maser radiation. Results of previous studies suggest that the compact maser spots are associated with the highly collimated out ow from the accreting young stellar object. The brightness temperature of the detected compact maser spot can exceed 1015 K. Correlated signals were obtained between the space and ground telescopes in two sessions. The 40-m radio telescope in Yebes (Spain), and the 32-m radio telescope in Torun (Poland) took part in the first session on 29 November 2013. The projected baseline length reached 3.5 Earth diameters, corresponding to a fringe spacing of ~63 μas. This corresponds to a linear size of about 3 solar diameters. In the second session (25 December 2013) Orion KL was detected on a baseline to the 26-m radio telescope in Hartebeesthoek (South Africa) with projected baseline of 2 Earth diameters. In both sessions VLSR and line width of the detected maser detail were around 7.3 km/s and ~0.5 km/s, respectively.
Observations of the most luminous water maser source in the Galaxy, star-forming region W49 N, also resulted in a successful fringe detection. W49 N is located at a distance of about 11 Kpc from the Sun in a distant part of the Perseus arm near the solar circle. A correlated signal was obtained on 2014 April, 18 between the space antenna and the 100-m ground radio telescope in Effelsberg (Germany). Projected baselines of the space-ground interferometer in the experiment reached up to about 3 Earth diameters (38,000 km), achieving a fringe-spacing resolution of ~70 μas.
A re-analysis of early RadioAstron observations at the ASC correlator has delivered a positive result for W3 (H2O), the bright water maser complex located ~6 arcseconds to the east of the W3 (OH) ultracompact H II region. A correlated signal was detected between the space antenna and the 100-m ground radio telescope in Effelsberg (Germany) and 40-m radio telescope in Yebes (Spain). Projected baselines of the space-ground interferometer in the experiment reached up to 3.8 Earth diameters (about 48,000 km), achieving a fringe-spacing resolution of ~58 μas.
The collected data on water masers are used to study structure and physical characteristics of the star forming regions in our Galaxy, impose tight limits on the sizes of individual maser spots, estimate brightness temperatures and provide the necessary input for the studies of their pumping mechanisms.

First imaging of water masers with RadioAstron

A RadioAstron imaging of a water maser in the star-forming region W3 IRS5 took place on 17 October 2013 with participation of the European VLBI Network (EVN) including the Russian network "Quasar". Interferometric signals have been detected up to 6 Earth diameters delivering a record angular resolution of 36μas for water masers. This corresponds to linear resolution of ~107 km. The space-ground interferometric image of the bright maser component in W3 IRS5 is shown in the left panel of Figure 2. The ground-only image has an extended structure, resolved out with the space-ground RadioAstron baselines except for a very compact peak visible up to the 6 Earth diameters. A joint analysis of the RadioAstron data and results of Japanese VERA interferometer monitoring allows international team of scientists to identify locations of the most compact maser emission (right panel, Figure 2).

Nikolai Kardashev (nkardash@asc.rssi.ru)
Yuri Kovalev (yyk@asc.rssi.ru)





Offline Salo

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Re: Russian RadioAstron (Spectr-R) update
« Reply #55 on: 05/28/2015 04:32 PM »
http://www.asc.rssi.ru/radioastron/news/news_en.pdf

======================
Astro Space Center
RadioAstron Newsletter
Number 28
28 May 2015
======================

The RadioAstron AO-3 open science program starts in July 2015

We are happy to report that RadioAstron operations are extended by Roscosmos until the end of 2016.
The second year of the RadioAstron open science program AO-2 is coming to its end in June 2015. Astro Space Center and its Russian and international partners have successfuly performed science experiments within approved AO-2 projects (see the list of projects in the RadioAstron Newsletter No. 24).
Starting from July 2015, the RadioAstron mission will move into the third year of its open program, AO-3 observations will continue until June 2016. The third RadioAstron Announcement of Opportunity has invited proposals of the following two types: the “Key Science Program” (KSP) and “General Observing Time” (GOT). See for details the full set of announcement documents in http://www.asc.rssi.ru/radioastron/ao-3/ao3.html.
All proposal were evaluated by the RadioAstron Program Evaluation Committee (RPEC) which was appointed by the RadioAstron International Science Council (RISC). Results of the evaluation were approved by the RadioAstron project director Nikolai Kardashev. RPEC members for AO-3 are Jason Hessels (U. Amsterdam, the Netherlands), David Jauncey (CSIRO, Australia), Matthew Lister (Purdue U., USA), Mikhail Popov (ASC Lebedev, Russia), Richard Porcas (chair, MPIfR, Germany), Wouter Vlemmings (Chalmers U., Sweden). Below we list 9 accepted projects which have requested observations with RadioAstron during the AO-3 period in their submission order:

• GOT: “Tracing micro-structures of H2O masers with ultimate angular resolution”, PIs: Hiroshi
Imai (Kagoshima U., Japan), Alexey Alakoz (ASC Lebedev, Russia);
• GOT: “Second-epoch Space VLBI visit into core-jet laboratories in the distant Universe”, PI:
Leonid Gurvits (JIVE and TU Delft, the Netherlands);
• KSP: “Space VLBI Survey of AGN at the Highest Angular Resolutions”, PI: Yuri Kovalev (ASC
Lebedev, Russia);
• KSP: “Probing the innermost regions of AGN jets and their magnetic fields”, PI: Jose-Luis
Gomez (IAA, Spain);
• KSP: “Gravitational redshift experiment with RadioAstron”, PI: Valentin Rudenko (SAI MSU,
Russia);
• GOT: “Resolving the milli-parsec jet in the nearby spiral galaxy M81”, PI: Michael Bietenholz
(HartRAO, South Africa; York U., Canada);
• GOT: “Substructure in Pulsar Scattering Disks”, PI: Carl Gwinn (UCSB, USA);
• GOT: “Core shifts with no blending”, PI: Mikhail Lisakov (ASC Lebedev, Russia);
• GOT: “H2O megamasers at high resolution”, PI: Willem Baan (ASTRON, the Netherlans;
ShAO, China).

Among the approved projects, four got rank ‘A’ (the highest priority), two — rank ‘B’, and three — rank ‘C’. A total of about 160 co-investigators represent 20 countries. The largest number of co-Is are from Russia, other countries with a high number of co-investigators are the USA, Germany, Spain, the Netherlands, Australia, Italy, UK, etc.

Nikolai Kardashev (nkardash@asc.rssi.ru)
Yuri Kovalev (yyk@asc.rssi.ru)

The RadioAstron project is led by the Astro Space Center of the Lebedev Physical Institute of the Russian Academy of Sciences and the Lavochkin Scientific and Production Association under a contract with the Russian Federal Space Agency, in collaboration with partner organizations in
Russia and other countries.

To subscribe or un-subscribe to the Newsletter, use: http://asc-lebedev.ru/index2.php?engdep=22

Offline Artyom.

Re: Russian RadioAstron (Spectr-R) update
« Reply #56 on: 07/18/2015 10:17 AM »
======================
Astro Space Center
RadioAstron Newsletter
Number 29
18 July 2015
======================

Four years since the launch

Today is the fourth year birth day of the RadioAstron Space Radio Telescope Spektr-R! We
would like to express our congratulations and deep thanks to all the institutions and individuals
involved in the mission’s operations and science.
Several weeks ago AO3 observations have started.

Read more:
"Earth is the cradle of humanity, but one cannot live in a cradle forever." - Konstantin Eduardovich Tsiolkovsky.

Offline Star One

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Re: Russian RadioAstron (Spectr-R) update
« Reply #57 on: 02/02/2016 06:49 PM »
Quote
We present the first polarimetric space VLBI imaging observations at 22 GHz. BL Lacertae was observed in 2013 November 10 with the RadioAstron space VLBI mission, including a ground array of 15 radio telescopes. The instrumental polarization of the space radio telescope is found to be within 9%, demonstrating the polarimetric imaging capabilities of RadioAstron at 22 GHz. Ground-space fringes were obtained up to a projected baseline distance of 7.9 Earth's diameters in length, allowing us to image the jet in BL Lacertae with a maximum angular resolution of 21 μas, the highest achieved to date. We find evidence for emission upstream of the radio core, which may correspond to a recollimation shock at about 40 μas from the jet apex, in a pattern that includes other recollimation shocks at approximately 100 μas and 250 μas from the jet apex. Polarized emission is detected in two components within the innermost 0.5 mas from the core, as well as in some knots 3 mas downstream. Faraday rotation analysis, obtained from combining RadioAstron 22 GHz and ground-based 15 GHz and 43 GHz images, shows a gradient in rotation measure and Faraday corrected polarization vector as a function of position angle with respect to the core, suggesting that the jet in BL Lacertae is threaded by a helical magnetic field. The intrinsic de-boosted brightness temperature in the unresolved core exceeds 3×1012 K, suggesting at the very least departure from equipartition of energy between the magnetic field and radiating particles.

http://arxiv.org/abs/1512.04690

Offline Star One

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Russian RadioAstron (Spectr-R) update
« Reply #58 on: 04/11/2016 06:55 PM »
Astronomers Can't Explain How These Trillion-Degree Quasars Got So Hot

Russian space telescope reveals a quasar whose absurd temperature cannot be explained.

Quote
Astrophysicists have spotted a faraway object that's hotter than any contemporary theory can explain, a discovery that might require scientists rewriting galaxy operation manuals for years to come. The first fruits of these mind-boggling observations were just published by an international group of scientists led by the Russian astrophysicist Yuri Kovalev in the journal Astrophysical Journal Letters.

"I believe that behind this remarkable result lies a new chapter in the exploration of the faraway universe," said Nikolai Kardashev, the head of the Spektr-R (Radioastron) orbital observatory project, which was instrumental in the latest breakthrough.

Quote
In the meantime, the Spektr-R space observatory presses on mission. Launched on a Ukrainian-built Zenit rocket on July 18, 2011, the satellite is about to exceed its five-year manufacturer warranty.Although harsh conditions of space, particularly radiation, are taking their toll on the spacecraft, the flight control team so far has managed to continue a productive scientific mission by switching to backup systems. According to Kovalev, technical issues have not yet degraded the scientific results.

Inspired by the success of Spektr-R, Russian scientists proposed a much more complex space radio telescope known as Spektr-M or Millimetron. The new instrument will be able to register millimeter and sub-millimeter bands of electromagnetic spectrum not only in conjunction with ground-based antennas but also on its own, peering farther into the Universe than any ground-based telescope can. Because of its high cost and many technical hurdles, though, Spektr-M is not expected to blast off into orbit before 2025.

http://www.popularmechanics.com/space/deep-space/a20351/quasar-temperature/
« Last Edit: 04/11/2016 07:02 PM by Star One »

Offline Salo

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Re: Russian RadioAstron (Spectr-R) update
« Reply #59 on: 06/21/2016 05:26 AM »
http://www.asc.rssi.ru/radioastron/news/news_en.pdf

======================
Astro Space Center
RadioAstron Newsletter
Number 30
20 June 2016
======================
The RadioAstron extension and AO-4 open science program start in July 2016

We are happy to report that RadioAstron operations are extended by Roscosmos until the end of 2018.
The third year of the RadioAstron open science program AO-3 is coming to its end in July 2016.  Astro Space Center and its russian and international partners have successfuly performed science experiments within approved AO-3 projects (see the list of projects in the RadioAstron Newsletter No. 28).
Starting from July 2016, the RadioAstron mission will move into the fourth year of its open program, AO-4 observations will continue until June 2017.  The fourth RadioAstron Announcement of Opportunity has invited proposals of the following two types:  the \Key Science Program" (KSP) and \General Observing Time" (GOT). See for details the full set of announcement documents in http://www.asc.rssi.ru/radioastron/ao-4/ao4.html .
All proposal were evaluated by the RadioAstron Program Evaluation Committee (RPEC) which was appointed by the RadioAstron International Science Council (RISC). Results of the evaluation were approved by the RadioAstron project director Nikolai Kardashev.  RPEC members for AO-4 are Jason Hessels (U. Amsterdam, the Netherlands), David Jauncey (CSIRO, Australia), Matthew Lister (Purdue U., USA), Mikhail Popov (ASC Lebedev, Russia), Richard Porcas (chair, MPIfR, Germany), Wouter Vlemmings (Chalmers U., Sweden).  Below we list 11 accepted projects which have requested observations with RadioAstron during the AO-4 period in their submission order:
• GOT: \Mapping and monitoring of cores of H2O masers with ultimate angular resolution", PIs: Hiroshi Imai (Kagoshima U., Japan), Alexey Alakoz (ASC Lebedev, Russia);
• GOT: \Angular diameters of pulsar scattering disks and the distribution of interstellar plasma fluctuations", PI: Mikhail Popov (ASC Lebedev, Russia);
• GOT: \Second-epoch Space VLBI visit into core-jet laboratories in the distant Universe (continued)", PI: Leonid Gurvits (JIVE and TU Delft, the Netherlands);
• GOT: \The nuclear structure of 3C84 with Space VLBI { II epoch", PI: Gabriele Giovannini (Bologona U. and INAF, Italy);
• GOT: \H2O megamaser sources at high resolution", PI: Willem Baan (ASTRON, the Netherlans; ShAO, China).
• KSP:  \Probing  the  innermost  regions  of  AGN  jets  and  their  magnetic   elds",  PI:  Jose-Luis Gomez (IAA, Spain);
• KSP: \Monitoring of the brightest AGN cores with RadioAstron", PI: Yuri Kovalev (ASC Lebedev, Russia);
• GOT: \A milli-arcsecond gravitational lens in S5 B0615+820?", PI: Eduardo Ros (MPIfR, Germany; U. Valencia, Spain);
• GOT:  \Resolving  the  Jet-Collimation  Region  of  the  NGC1052  Twin-Jet  System",  PI:  Anne-Kathrin Baczko (MPIfR, Germany);
• KSP: \Gravitational redshift experiment with RadioAstron", PI: Valentin Rudenko (SAI MSU, Russia);
• GOT: \Joint Pulsar { AGN Ground-Space VLBI", PI: Vladimir Soglasnov (ASC Lebedev, Russia).
Among the approved projects, four got rank `A' (the highest priority), three | rank `B', and four | rank `C'. A total of about 155 co-investigators represent 19 countries.  The largest number of  co-Is  are  from  Russia,  other  countries  with  a  high  number  of  co-investigators  are  the  USA, Germany, Spain, the Netherlands, Australia, Italy, etc.

RadioAstron science results

We are happy to note the growing number of RadioAstron publications ( http://www.asc.rssi.ru/radioastron/publications/publ.html )  as  well  as  many  reports  on  science  meetings  including the recent \Dissecting the Universe" workshop in Bonn ( https://events.mpifr-bonn.mpg.de/indico/event/4/timetable/ ) and \Blazars through Sharp Multi-Wavelength Eyes" in Malaga ( http://jets2016.iaa.es/content/program ).
On June 20-22, 2016, many colleagues gather in Moscow to celebrate the 100 years anniversary of Iosif Shklovsky at the Shklovsky-100 symposium ( http://shklovsky100.asc.rssi.ru/index.php/en/programm ).

Nikolai Kardashev (nkardash@asc.rssi.ru)
Yuri Kovalev (yyk@asc.rssi.ru)

The RadioAstron project is led by the Astro Space Center of the Lebedev Physical Institute of the Russian Academy of Sciences and the Lavochkin Scientific and Production Association under a contract with the Russian Federal Space Agency, in collaboration with partner organizations in Russia and other countries.

Offline Salo

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Re: Russian RadioAstron (Spectr-R) update
« Reply #60 on: 12/21/2016 04:16 PM »
http://www.asc.rssi.ru/radioastron/ao-5/ao5.html
RadioAstron Announcement of Opportunity - 5

 The space VLBI Mission RadioAstron, led by the Astro Space Center (ASC) of Lebedev Physical Institute, provides a range of specific and unique capabilities for detecting and imaging sources of cosmic radio emission at the highest angular resolution. The optimal utilization of these capabilities relies on the construction and execution of a balanced scientific program for the Mission. Proposals are invited for the RadioAstron Key Science Program and General Observing Time experiments to be submitted by 23 January 2017, 23:59 UT, to the Mission, and to ground radio telescopes required for the specific observations by their respective proposal deadlines. AO-5 observations will be performed between July 2017 and June 2018 inclusive.
 Proposals are to be submitted by e-mail as single pdf files to the address: ra_submit@asc.rssi.ru

 List of AO-5 related documents

- The RadioAstron Announcement of Opportunity - 5;
- The RadioAstron User Handbook;
- Full Proposal template: LaTeX file and pdf file;
- All-sky uv-coverage simulations with Pushchino and Green Bank tracking stations: pdf file;
- ASCII table with RadioAstron AO-5 visibility prediction for selected targets from the RadioAstron list of observed sources;
- Fakerat full binary package (is tested to work with most Linux distributions) including installation README, manual, and predicted RadioAstron AO5 orbit prior to the maneuver planned for 2017-07-16 and after it (ASCII files);
- All documents collected togeter in a zip-file
- RadioAstron observations status summary. Acknowledgment for the project publications

 To subscribe to RadioAstron Newsletter click here
« Last Edit: 12/21/2016 04:34 PM by Salo »

Offline Salo

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Re: Russian RadioAstron (Spectr-R) update
« Reply #61 on: 03/15/2017 04:09 PM »
http://www.asc.rssi.ru/radioastron/news/newsl/en/newsl_31_en.pdf
======================
Astro Space Center
RadioAstron Newsletter
Number 31
15 March 2017
======================

The RadioAstron AO-5 open science program: July 2017 – June 2018

The  RadioAstron  observations  currently  cover  the  fourth  year  of  the  open  program  within  the approved AO-4 proposals.  Starting from July 2017, the RadioAstron mission will move into the fifth year of its program, AO-5 observations will continue until June 2018.  We note that an orbit correction is planned for July 2017 which will affect the RadioAstron observing schedule in July and  August  2017.   The  fifth  RadioAstron  Announcement  of  Opportunity  has  invited  proposals of the following two types:  the “Key Science Program” (KSP) and “General Observing Time” (GOT).  See  for  details  the  full  set  of  announcement  documents  in http://www.asc.rssi.ru/radioastron/ao-5/ao5.html .
All proposal were evaluated by the RadioAstron Program Evaluation Committee (RPEC) which was appointed by the RadioAstron International Science Council (RISC). Results of the evaluation were approved by the RadioAstron project director Nikolai Kardashev.  RPEC members for AO-5 are Jason Hessels (U. Amsterdam, the Netherlands), David Jauncey (CSIRO, Australia), Matthew Lister (Purdue U., USA), Alexander Pushkarev (CrAO, Russia), Mark Reid (chair, Harvard CfA, USA), Olaf Wucknitz (MPIfR, Germany). Below we list 11 accepted projects which have requested observations with RadioAstron during the AO-5 period in their submission order:

• GOT: “Visibility tracking of hyper-compact H2O maser spots for studying interstellar microturbulence”, PIs:  Hiroshi Imai (Kagoshima U., Japan), Alexey Alakoz (ASC Lebedev, Russia);
• GOT: “Monitoring of substructure in scattering disk of pulsar radio emission”, PI: Carl Gwinn (UCSB, USA);
• GOT: “Brightest objects in the distant Universe”, PI: Leonid Gurvits (JIVE and TU Delft, the Netherlands);
• KSP: “Evolution of high brightness temperature AGN cores with RadioAstron”, PI: Yuri Kovalev (ASC Lebedev, Russia);
• KSP:  “Probing  the  innermost  regions  of  AGN  jets  and  their  magnetic  fields”,  PI:  Jose-Luis Gomez (IAA, Spain);
• GOT: “Probing interstellar scattering material using dense RadioAstron observations of refractive substructure in AGN”, PI: Mikhail Lisakov (ASC Lebedev, Russia);
• GOT: “Observations of the central maser regions in H2O megamaser NGC4258 with ultimate angular resolution”, PI: Willem Baan (ASTRON, the Netherlans).
• GOT: “Early stages of massive star formation regions as seen with RadioAstron in H2O maser lines”, PI: Stan Kurtz (UNAM, Mexico);
• KSP: “Gravitational redshift experiment with RadioAstron”, PI: Valentin Rudenko (SAI MSU, Russia);
• KSP:  “The  nuclear  structure  in  M87  with  RadioAstron”,  PI:  Tuomas  Savolainen  (Aalto  U., Finland; MPIfR, Germany);
• GOT: “Resolving the gamma-ray production region in sources J0211+1051 and S5 1044+71”, PI: Victor Patino-Alvares (MPIfR, Germany).

Among the approved projects, six got rank ‘A’ (the highest priority).  A total of more than 160 co-investigators represent 20 countries.  The largest number of co-Is are from Russia, other countries with a high number of co-investigators include the USA, Germany, Spain, the Netherlands, Australia, Canada.

The absolute record of angular resolution by RadioAstron. Again.

While the readers are welcome to enjoy recent RadioAstron publications
( http://www.asc.rssi.ru/radioastron/publications/publ.html ), we are happy to announce a new absolute record of the angular resolution which was achieved detecting the megamaser in NGC 4258 at 1.3 cm on the
RadioAstron Space Radio Telescope to Medicina (Italy) baseline of 340,000 kilometers (26.7 Earth diameters,  8 μas).  The previous record of 11 μas on the same megamaser by the RadioAstron SRT to the GBT baseline was announced during the EVN symposium in Sankt-Petersburg.
In the same time, within a dedicated experiment on the glorious pair of the quasars 3C 273 and 3C 279, a very compact core was detected in 3C 279 at 1.3 cm by the SRT to the Jansky VLA baseline of 235,000 kilometers (18.5 Earth diameters, 12 μas).
These results are crucial to probe the physics of both the water vapor megamasers and the extremely bright and compact cores of quasars.

Nikolai Kardashev (nkardash@asc.rssi.ru)
Yuri Kovalev (yyk@asc.rssi.ru)

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