Scientists believe they are on the verge of obtaining the first ever picture of a black hole.They have built an Earth-sized "virtual telescope" by linking a large array of radio receivers - from the South Pole, to Hawaii, to the Americas and Europe.There is optimism that observations to be conducted during 5-14 April could finally deliver the long-sought prize.In the sights of the so-called "Event Horizon Telescope" will be the monster black hole at the centre of our galaxy.Although never seen directly, this object, catalogued as Sagittarius A*, has been determined to exist from the way it influences the orbits of nearby stars.These race around a point in space at many thousands of km per second, suggesting the hole likely has a mass of about four million times that of the Sun.But as colossal as that sounds, the "edge" of the black hole - the horizon inside which an immense gravity field traps all light - may be no more than 20 million km or so across.And at a distance of 26,000 light-years from Earth, this makes Sagittarius A* a tiny pinprick on the sky.The Event Horizon Telescope (EHT) team is nonetheless bullish."There's great excitement," said project leader Sheperd Doeleman from the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts."We've been fashioning our virtual telescope for almost two decades now, and in April we're going to make the observations that we think have the first real chance of bringing a black hole's event horizon into focus," he told BBC News.
Spect-R works at much longer wavelengths. There are not that many observatories working at ~1 mm. Nobeyama is the only one that comes to mind immediately that is not (AFAIK) already/soon used in EHT.There's also a new telescope being constructed on top of Greenland's ice sheet, which will be used for EHT.
Quote from: as58 on 02/16/2017 10:12 pmSpect-R works at much longer wavelengths. There are not that many observatories working at ~1 mm. Nobeyama is the only one that comes to mind immediately that is not (AFAIK) already/soon used in EHT.There's also a new telescope being constructed on top of Greenland's ice sheet, which will be used for EHT.Are the wavelengths it operates in a result of it being an orbital rather than ground based observatory?
Preliminary image of the black hole:
I've been looking forward to this for some time now. I hope the results are worth this hype!
Quote from: ugordan on 04/01/2019 04:11 pmI've been looking forward to this for some time now. I hope the results are worth this hype!Some online have complained that announcing this on April Fools day wasn’t a good idea, seemingly ignoring the fact that I don’t believe all countries have such a day.
IIRC, they were looking first at Sgr A* in our own galactic center and the black hole in the nucleus of M87. Wonder which one they finished with first?
I'm thinking Sgr A*, just because it's a bigger impact as it's in our backyard and not some "random" galaxy out there.
Quote from: ugordan on 04/01/2019 06:53 pmI'm thinking Sgr A*, just because it's a bigger impact as it's in our backyard and not some "random" galaxy out there.Actually, are there any other plausible targets? Messier 87 is by far the closest of the really massive ones.
Are there any plans to add the Tianyan radio telescope to this collective?
Documentary following researchers as they try to take the first-ever picture of a black hole. They must travel the globe to build a revolutionary telescope that spans planet Earth.
Any news about the imaging of sagittarius a?
Quote from: Star One on 04/10/2019 01:16 pmAny news about the imaging of sagittarius a?Just confirmed SgA* analysis is ongoing and are confident they will soon be able to release images. Probably hindered by a much more dirty background.
They imaged Messier-87* first because it is 1000 times larger than Sgr-A* but also 1000 times further away, so the relative size is approximately the same. This wasn't well constrained at all, so it was kind of a lucky shot. However, Sgr-A* is rotating much faster, so this makes it much more difficult to get a sharp image of it. Also mentioned how the accretion plasma is quite "optically" (in radio, obviously) thin in M87*, so they can see the shadow - which is quite an interesting result just by itself.
Quote from: eeergo on 04/10/2019 01:36 pmThey imaged Messier-87* first because it is 1000 times larger than Sgr-A* but also 1000 times further away, so the relative size is approximately the same. This wasn't well constrained at all, so it was kind of a lucky shot. However, Sgr-A* is rotating much faster, so this makes it much more difficult to get a sharp image of it. Also mentioned how the accretion plasma is quite "optically" (in radio, obviously) thin in M87*, so they can see the shadow - which is quite an interesting result just by itself.It’s interesting that our BH is more rapidly rotating is that a function of its smaller size/mass?
Rotation rate is very difficult to measure with precision because of the relativistic light-bending. Think the spinning exists, and is pointing away from us (its vector) because of the energetic jets that are visible.For now, they have a "sense" of rotation only: its clockwise direction.Polarization of the light is already inherent to the released data (but still not fully analyzed). It will shed light on M87*'s magnetic fields, which will also give more clues as to how it's rotating.
Quote from: eeergo on 04/10/2019 01:51 pmRotation rate is very difficult to measure with precision because of the relativistic light-bending. Think the spinning exists, and is pointing away from us (its vector) because of the energetic jets that are visible.For now, they have a "sense" of rotation only: its clockwise direction.Polarization of the light is already inherent to the released data (but still not fully analyzed). It will shed light on M87*'s magnetic fields, which will also give more clues as to how it's rotating.By the way thanks for covering this news conference on here.
Just a reminder about this documentary showing in the U.K. tonight.Documentary to be shown on BBC 4 in the U.K. on the 10th April.How to See a Black Hole: The Universe’s Greatest MysteryQuoteDocumentary following researchers as they try to take the first-ever picture of a black hole. They must travel the globe to build a revolutionary telescope that spans planet Earth.
Quote from: Star One on 04/10/2019 03:53 pmJust a reminder about this documentary showing in the U.K. tonight.Documentary to be shown on BBC 4 in the U.K. on the 10th April.How to See a Black Hole: The Universe’s Greatest MysteryQuoteDocumentary following researchers as they try to take the first-ever picture of a black hole. They must travel the globe to build a revolutionary telescope that spans planet Earth.How about someone record this and either put it in L2 or on NSF's YouTube site?
Also, how 'bout that old Einstein guy?
Quote from: seawolfe on 04/10/2019 04:17 pmQuote from: Star One on 04/10/2019 03:53 pmJust a reminder about this documentary showing in the U.K. tonight.Documentary to be shown on BBC 4 in the U.K. on the 10th April.How to See a Black Hole: The Universe’s Greatest MysteryQuoteDocumentary following researchers as they try to take the first-ever picture of a black hole. They must travel the globe to build a revolutionary telescope that spans planet Earth.How about someone record this and either put it in L2 or on NSF's YouTube site?Can't do it because that would be a copyright violation. We don't want to get NSF in trouble.
Quote from: ugordan on 04/10/2019 04:35 pmAlso, how 'bout that old Einstein guy?Let's also hear it for Roy Kerr, who found the solution for a rotating black hole
The EHT has also been observing Sagittarius A*, the supermassive black hole at the centre of the Milky Way. However, our galaxy is much 'messier' than M87 - meaning there is much more gas and dust that obscure the picture. The collaboration is still processing how to mitigate the effects of the matter lying between the Solar System and the Galactic centre. To help with that process, four more observatories are now joining the EHT."When Apollo [8] turned and took a picture of the Earth, we had this wonderful moment of seeing a picture that had not been seen before," Psaltis says, adding that the first image of a black hole might carry a similar emotional weight. "It's something that inspires and excites us."Natarajan agrees. "Black holes have this incredible gravitational pull for us. It's amazing that one happens to be alive at a time right when we're learning so much about black holes."
I’ve also heard they started with M87 because it’s 1000X more massive than Sgr A*. Plasma is whipping around our local black hole, potentially brightening and dimming the image in a matter of minutes. Things unfold more slowly out at M87, so it makes sense to start there first.
Isn’t that just a simulation and I watched that video and he didn’t point that out in it?
Quote from: Star One on 04/11/2019 05:50 amIsn’t that just a simulation and I watched that video and he didn’t point that out in it?Yes it is. It's confirmed in the comments of the original video from Goethe University by a person working there.
The astrophysicist Janna Levin reflects on the newly unveiled, first-ever photograph of a black hole.
The human side, from FB: https://m.facebook.com/ScienceNaturePage/photos/a.693601310772130/1630872857044966/?type=3&source=48
An Illustrated History of Black Hole Imaging : Personal Recollections (1972-2002)Jean-Pierre Luminethttps://arxiv.org/ftp/arxiv/papers/1902/1902.11196.pdf
The new name, "Pwehi," means "embellished dark source of unending creation" in the indigenous Hawaiian language, and it was selected by Larry Kimura, a Hawaiian language professor at the University of Hawaii, Hilo (UH), according to a statement released by the university on April 10.
"It turns out that even now, with what we have, we may be able, with certain prior assumptions, to look at rotational signatures [evidence of the accretion disk swirling around the event horizon]," Doeleman said. "And then, if we had many more stations, then we could really start to see in real time movies of the black hole accretion and rotation." [9 Ideas About Black Holes That Will Blow Your Mind]
There's a bright magnetar photobombing the supermassive black hole at the center of the Milky Way, frustrating astronomers' efforts to study the black hole — called Sagittarius A* — using X-ray telescopes.SagA* is the nearest known supermassive black hole to Earth. And while it's far smaller, quieter and dimmer than the recently imaged black hole at the center of the galaxy Messier 87, it still represents one of the best opportunities astronomers have for understanding how black holes behave and interact with their surrounding environments. But back in 2013, a magnetar — an ultradense star (also called a neutron star) wrapped in powerful magnetic fields — between SagA* and Earth lit up, and ever since has been messing with efforts to observe the black hole using X-ray telescopes.
The concept called the Event Horizon Imager (EHI) was dreamed up by a team of astronomers at Radboud University in the Netherlands. They’re hoping to make their project a reality with help from the European Space Agency (ESA).“There are lots of advantages to using satellites instead of permanent radio telescopes on Earth, as with the Event Horizon Telescope (EHT),” said Freek Roelofs, a PhD candidate at Radboud University and the lead author of the article, in a statement. “In space, you can make observations at higher radio frequencies, because the frequencies from Earth are filtered out by the atmosphere.”
An initial design study of the concept has been presented as the Event Horizon Imager (EHI). The EHI may be suitable for imaging Sgr A* at high frequencies (up to ~690 GHz), which has significant advantages over performing ground-based VLBI at 230 GHz. The concept EHI design consists of two or three satellites in polar or equatorial circular Medium-Earth Orbits with slightly different radii. Due to the relative drift of the satellites along the individual orbits, this setup will result in a dense spiral-shaped uv-coverage with long baselines (up to ~60 Glambda), allowing for extremely high-resolution and high-fidelity imaging of radio sources.
The resolution would be several times better than EHT - though I am unsure if the suggested 25m dishes have any open space heritige.
Orion/Mentor SIGINT spy satellites are rumored to have deployable dishes with a diameter in excess of 100m in deployed configuration
The Event Horizon Telescope (EHT) team took humanity to the heart of darkness when it unveiled the world’s first direct image of a black hole in April1,2,3,4,5,6. That feat has now earned the team one of this year’s US$3-million Breakthrough prizes — one of the most lucrative awards in science and mathematics.
The team that took the first ever image of a black hole has announced plans to capture "razor sharp" full colour video of the one at the centre of our galaxy.Satellites would be launched to supplement the existing network of eight telescopes to make this movie.The researchers say the upgraded network will be able to see the supermassive black hole consuming the material around it.
62 micro-arcseconds is the size of the image, as small as a doughnut on the Moon seen from Earth (3 million times as sharp as a human eye, also equivalent to seeing the bubbles on a New Yorker beer glass from Munich). But the actual black hole is the size of Mercury's orbit, with a mass of 4 million solar masses.
I wonder why it's so tilted with respect to the galactic plane? I'd have expected it to have little or no tilt in that respect--meaning it would be edge-on to us. But, according to the paper, they eliminated all edge-on (aka "high-inclination") models and ended up with ones that were more face-on. That really surprises me.
Quote from: Greg Hullender on 05/12/2022 03:18 pmI wonder why it's so tilted with respect to the galactic plane? I'd have expected it to have little or no tilt in that respect--meaning it would be edge-on to us. But, according to the paper, <a href="https://iopscience.iop.org/article/10.3847/2041-8213/ac6674#:~:text=All%20edge%2Don%20(high%20inclination)%20models%20fail%20the%20combined%20set%20of%20EHT%2Donly%20constraints%20for%20at%20least%20one%20simulation">they eliminated all edge-on (aka "high-inclination") models</a> and ended up with ones that were more face-on. That really surprises me.That struck me as well, but I'd guess it has a lot to do with the genesis and development of the galaxy -- e.g., how material in the proto-nebula entered the initial black hole, the resulting spin after past galactic mergers, etc. I'll also be interested in whether the earlier analyses of interactions between the objects orbiting in close proximity to the hole will be revisited now that we have a better idea of the size and orientation of the accretion disk.
I wonder why it's so tilted with respect to the galactic plane? I'd have expected it to have little or no tilt in that respect--meaning it would be edge-on to us. But, according to the paper, <a href="https://iopscience.iop.org/article/10.3847/2041-8213/ac6674#:~:text=All%20edge%2Don%20(high%20inclination)%20models%20fail%20the%20combined%20set%20of%20EHT%2Donly%20constraints%20for%20at%20least%20one%20simulation">they eliminated all edge-on (aka "high-inclination") models</a> and ended up with ones that were more face-on. That really surprises me.
Quote from: rsnellenberger on 05/12/2022 04:32 pmQuote from: Greg Hullender on 05/12/2022 03:18 pmI wonder why it's so tilted with respect to the galactic plane? I'd have expected it to have little or no tilt in that respect--meaning it would be edge-on to us. But, according to the paper, <a href="https://iopscience.iop.org/article/10.3847/2041-8213/ac6674#:~:text=All%20edge%2Don%20(high%20inclination)%20models%20fail%20the%20combined%20set%20of%20EHT%2Donly%20constraints%20for%20at%20least%20one%20simulation">they eliminated all edge-on (aka "high-inclination") models</a> and ended up with ones that were more face-on. That really surprises me.That struck me as well, but I'd guess it has a lot to do with the genesis and development of the galaxy -- e.g., how material in the proto-nebula entered the initial black hole, the resulting spin after past galactic mergers, etc. I'll also be interested in whether the earlier analyses of interactions between the objects orbiting in close proximity to the hole will be revisited now that we have a better idea of the size and orientation of the accretion disk.Couldn’t it have got ‘disarranged’ by previous galactic mergers. We now have evidence for several of these and wouldn’t the black holes from the merging galaxies have sunk towards the centre and merged with Sagittarius-A*.
Quote from: Star One on 05/12/2022 04:35 pmQuote from: rsnellenberger on 05/12/2022 04:32 pmQuote from: Greg Hullender on 05/12/2022 03:18 pmI wonder why it's so tilted with respect to the galactic plane? I'd have expected it to have little or no tilt in that respect--meaning it would be edge-on to us. But, according to the paper, <a href="https://iopscience.iop.org/article/10.3847/2041-8213/ac6674#:~:text=All%20edge%2Don%20(high%20inclination)%20models%20fail%20the%20combined%20set%20of%20EHT%2Donly%20constraints%20for%20at%20least%20one%20simulation">they eliminated all edge-on (aka "high-inclination") models</a> and ended up with ones that were more face-on. That really surprises me.That struck me as well, but I'd guess it has a lot to do with the genesis and development of the galaxy -- e.g., how material in the proto-nebula entered the initial black hole, the resulting spin after past galactic mergers, etc. I'll also be interested in whether the earlier analyses of interactions between the objects orbiting in close proximity to the hole will be revisited now that we have a better idea of the size and orientation of the accretion disk.Couldn’t it have got ‘disarranged’ by previous galactic mergers. We now have evidence for several of these and wouldn’t the black holes from the merging galaxies have sunk towards the centre and merged with Sagittarius-A*.Quote from one of the "forefathers" of this image:https://twitter.com/hfalcke/status/1524749672715194377
Yes, the black hole is small compared to the Milky Way, but I'm not sure how that's relevant. You'd think that the material falling into it over the past 12 billion years would, on average, give it angular momentum with a spin axis pretty close to that of the galaxy itself. Or perhaps there was an off-center merger with the black hole from another galaxy sometime in the past. I wonder how destructive that would have been to the rest of the galaxy. Yes, that depends on the mass of the other black hole, but it needed to be massive enough to knock Sag. A* out of kilter, so probably a million solar masses or more.
<snip>... but I wonder if they are remnants of weak jets from slightly more active periods in SagA*'s life, or otherwise some ejection from it. They would seem to point to a non-zero inclination from a completely naïve point of view.
Quote from: eeergo on 05/12/2022 04:11 pm<snip>... but I wonder if they are remnants of weak jets from slightly more active periods in SagA*'s life, or otherwise some ejection from it. They would seem to point to a non-zero inclination from a completely naïve point of view.I think that scientists have been (and still are) trying to do this. One problem is to identify which of the many features in the Galactic Center environment might trace back to Sgr A*. The GC region is a very dynamic and energetic environment, as visualised in the attached MeerKAT radio images. Massive and very luminous stars add lots of "energy" in form of stellar winds and ionising radiation, and create bubbles and shockwaves once they go supernova. Ionised matter also attaches to magnetic fields (like, e.g., the "radio arc" feature to the "left" of the center). Note that the EHT image displays structures on scales of 50 micro-arc-seconds, while 1 pixel in the first attached MeerKAT image corresponds to 1 arc-seconds, i.e. a factor of more than 20 000 difference in angular resolution.https://apod.nasa.gov/apod/ap220202.html
Quote from: Greg Hullender on 05/12/2022 05:04 pmYes, the black hole is small compared to the Milky Way, but I'm not sure how that's relevant. You'd think that the material falling into it over the past 12 billion years would, on average, give it angular momentum with a spin axis pretty close to that of the galaxy itself. Or perhaps there was an off-center merger with the black hole from another galaxy sometime in the past. I wonder how destructive that would have been to the rest of the galaxy. Yes, that depends on the mass of the other black hole, but it needed to be massive enough to knock Sag. A* out of kilter, so probably a million solar masses or more.I've heard that the milky way is rather odd in that Sag A* is so small compared to the size of the galaxy. Our merger history is gentler and doesn't include alot of dwarf galaxies with their own super massive black holes.
Quote from: eeergo on 05/12/2022 04:11 pm<snip>... but I wonder if they are remnants of weak jets from slightly more active periods in SagA*'s life, or otherwise some ejection from it. They would seem to point to a non-zero inclination from a completely naïve point of view.I think that scientists have been (and still are) trying to do this. One problem is to identify which of the many features in the Galactic Center environment might trace back to Sgr A*. The GC region is a very dynamic and energetic environment, as visualised in the attached MeerKAT radio images. Massive and very luminous stars add lots of "energy" in form of stellar winds and ionising radiation, and create bubbles and shockwaves once they go supernova. Ionised matter also attaches to magnetic fields (like, e.g., the "radio arc" feature to the "left" of the center). Note that the EHT image displays structures on scales of 50 micro-arc-seconds, while 1 pixel in the first attached MeerKAT image corresponds to 1 arc-seconds, i.e. a factor of more than 20 000 difference in angular resolution.https://apod.nasa.gov/apod/ap220202.html
<snip>... but I wonder if they are remnants of weak jets from slightly more active periods in SagA*'s life, or otherwise some ejection from it. They would seem to point to a non-zero inclination from a completely naïve point of view.
To keep things interesting, this appeared recently on arXiv: https://arxiv.org/abs/2205.04623. The authors have done an independent image reconstruction using the public M87 EHT data and claim that the famous ring could be an artifact.
On some other sites, I'm seeing claims that the original data for these images is only 2x3 pixels. Is there any merit to that claim?
The longest baselines have an interferometric fringe spacing of 1/∣ u ∣ ≈ 24 μas, which defines the diffraction-limited angular resolution of the EHT. The visibility amplitudes have two deep minima, the first at ∣ u ∣ ≈ 3.0 Gλ and the second at ∣ u ∣ ≈ 6.5 Gλ. The amplitudes have a baseline dependence that is similar to that of an infinitesimally thin ring with a 54 μas diameter that has been blurred with a circular Gaussian kernel with 23 μas FWHM. The ring diameter is primarily constrained by the minima locations, while the width is determined by the amplitude of the secondary visibility peak between the minima.
Also the timing is suspicious -why publish a critique of M87*'s image at this very moment if not to call for attention- and the concluding remark too strong for a good-faith rebuke IMO.
QuoteThe longest baselines have an interferometric fringe spacing of 1/∣ u ∣ ≈ 24 μas, which defines the diffraction-limited angular resolution of the EHT. The visibility amplitudes have two deep minima, the first at ∣ u ∣ ≈ 3.0 Gλ and the second at ∣ u ∣ ≈ 6.5 Gλ. The amplitudes have a baseline dependence that is similar to that of an infinitesimally thin ring with a 54 μas diameter that has been blurred with a circular Gaussian kernel with 23 μas FWHM. The ring diameter is primarily constrained by the minima locations, while the width is determined by the amplitude of the secondary visibility peak between the minima.I must admit I haven't read the other technical papers yet, and as mentioned I don't have expertise in interferometry, but - is it me or does it read as if the inteferometer is diffraction-limited at the approximate thickness of both black hole images (20-something μas), and the interference fringes are a ring of the BH's inferred angular size with smearing equivalent to its width? That would be some bias, wouldn't it? Or am I reading it wrong (most likely)? If so, how should this be interpreted?
Quote from: eeergo on 05/13/2022 03:56 pmQuoteThe longest baselines have an interferometric fringe spacing of 1/∣ u ∣ ≈ 24 μas, which defines the diffraction-limited angular resolution of the EHT. The visibility amplitudes have two deep minima, the first at ∣ u ∣ ≈ 3.0 Gλ and the second at ∣ u ∣ ≈ 6.5 Gλ. The amplitudes have a baseline dependence that is similar to that of an infinitesimally thin ring with a 54 μas diameter that has been blurred with a circular Gaussian kernel with 23 μas FWHM. The ring diameter is primarily constrained by the minima locations, while the width is determined by the amplitude of the secondary visibility peak between the minima.I must admit I haven't read the other technical papers yet, and as mentioned I don't have expertise in interferometry, but - is it me or does it read as if the inteferometer is diffraction-limited at the approximate thickness of both black hole images (20-something μas), and the interference fringes are a ring of the BH's inferred angular size with smearing equivalent to its width? That would be some bias, wouldn't it? Or am I reading it wrong (most likely)? If so, how should this be interpreted?They don't measure the width, it's unresolved. What happens when you don't resolve a feature? You see the true scene convolved with the beam, which in this case is 24 uas. They're just saying that their visibility amplitudes are well fit by an infinitesimally narrow annulus which is then degraded to their resolution.
Thanks, that explanation is highly appreciated.If I may follow up: what is exactly meant by "visibility amplitude"? I may be lacking important terminology. I've been reading it as saying that this annulus is "built into" their image through diffraction and resolution smearing, which as you say then gets convolved with the scene - but wouldn't that then introduce the evident bias that most resolution-limited scenes would appear to show this ring, no matter their true shape... which coincidentally has the same approximate angular diameter as the observed object, which is also coincidentally the same apparent size as M87*? Where am I veering off course, since this would be too obvious a bias?
For those unaware: the Event Horizon Telescope team are the masterminds behind the stunning images of the Sagittarius A* & M87* black holes shown below.So this could be a particularly interesting announcement. 😮
So apparently the Event Horizon Telescope @ehtelescope folks have a big announcement this week, and the embargo lifts Wednesday at 9am.
Breaking news: the Event Horizon Telescope team unveils strong magnetic fields spiraling at the edge of Milky Way’s central black hole, Sagittarius A*. This new image suggests that strong magnetic fields may be common to all black holes.
The new images reveal even more similarities Between Sgr A* and M87* than the previous. An earlier study of M87* revealed the black hole launched jets of material into space and the current results suggest that the same might be happening at Sgr A*. Moreover, the similarities suggest that some processes are similar for all black holes, regardless of differences in mass and size.
New EHT test observations have achieved the highest-resolution detections of black holes from Earth. #blackholes #EHT #eventhorizon 1/🧵Image: Artist's impression showing radio signals from a distant galaxy detected by radio observatories worldwide. Credit: ESO/M. Kornmesser
The test was carried out by two small subarrays of the EHT—made up of @almaobs and @ApexTelescope in Chile, IRAM in Spain, the NOEMA in France, the Submillimeter Array (SMA) in Hawai'i, and the Greenland Telescope. 2/🧵Credit: CfA/SAO, Mel Weiss @melweiss
The new observations were made at 345 GHz, much higher than the previous 230 GHz. The higher the frequency, the sharper the image as seen here in this simulated side-by-side comparison of M87*. 3/🧵Credit: EHT, D. Pesce, A. Chael
This composite simulated image shows how M87* is seen by the EHT at 86 GHz (red), 230 GHz (green), and 345 GHz (blue). 345 GHz provides a more compact and sharper view of black holes, revealing structure, size, and shape with more clarity. 4/🧵Credit: EHT, D. Pesce, A. Chael
Ultimately, the increase in capability will make images of supermassive black holes 50% crisper and open new windows on the mysteries of these cosmic beasts. Read the open access paper below. 5/🧵https://iopscience.iop.org/article/10.3847/1538-3881/ad5bdb
In this pilot experiment, the Collaboration achieved observations with detail as fine as 19 microarcseconds, meaning they observed at the highest-ever resolution from the surface of Earth. They have not been able to obtain images yet, though: while they made robust detections of light from several distant galaxies, not enough antennas were used to be able to accurately reconstruct an image from the data.
The EHTC studied the spectacular flare observed during its second campaign on M87, involving over 25 ground-based and space-based telescopes. The authors report the first observation in over a decade of a high-energy gamma-ray flare.https://arxiv.org/abs/2404.17623
In 2017 the Event Horizon Telescope – a worldwide network of radio-telescopes – observed the supermassive black hole at the centre of the M87 galaxy, leading to the first ever image of a black hole, released in 2019. Now, using observations from 2017, 2018 and 2021, astronomers have found some changes in this now iconic image that could be caused by variations in the magnetic field around the black hole.
