Snapshot of M87 * black hole appearance obtained by imaging / geometric modeling and EHT array of telescopes in 2009-2017. The diameter of all the rings is the same, but the position of the bright side varies. Credit: M. Wilgus, de Pace and EHT collaborate
Analysis of the Horizon Telescope observations of the 2009-2017 event, showcasing the turbulent evolution of the M87 Black hole Image.
In 2019, the Event Horizon Telescope (EHT) collaborated to provide the first image of a black hole, revealing a supermassive object object in the center of the M87 * – M87 galaxy. The EHT team has now used the lessons learned last year to analyze the archival data sets for 2009-2013, some of which were not previously published. The analysis reveals the behavior of the image of a black hole over many years, showing a continuation of a crescent-like shadow feature, but also a variation in its approach – a crescent-shaped orbit. Full results appeared today Astrophysical Journal.
EHT is a global array of telescopes that perform synchronized observations using the technique of very long baseline interferometry (VLBI). Together they create a virtual earth-sized radio dish, providing a distinctive high-resolution image. “With EHT’s incredible angular resolution we can play billiards on the moon and not lose track of scores!” I mean Kiek Wilgus, astronomer at the Center for Astrophysics | Harvard and Smithsonian, Fellow of the Black Hole Initiative, and lead author of the paper. The MHA * early-AHT prototype array was observed in 2009-2013, consisting of telescopes located at three geographic sites in 2009-2012 and four sites in 2013. .
Animation representing one year of M87’s image evolution according to numerical simulation. The measured position angle of the bright side of the crescent is shown, with a 42 microcircus sec ring. For the part of the animation, the blurred image is shown in EHT resolution. Credit: G. Wong, b. Praether, c. Gami, m. Wilgus and EHT collaboration
“Last year we saw an image of a shadow of a black hole, including a bright crescent shaped by Garam. Plasma M87[.]Revolves around, and is a dark central part, where we expect a black hole event horizon, ”Wilgus said. “But those results were based solely on observations made in a one-week window in April 2017, which is too short to see too many changes. Based on last year’s results we asked the following questions: Is this semicircle-like morphology consistent with archival data? Do archival data indicate the same size and direction of the crescent? ”
Observations of the year 200 ob-201 ob contain much less data than the figures made in 2017, which makes it impossible to create an image. Instead, the EHT team used statistical modeling to observe changes in the appearance of the M87 * over time. While no assumptions about source morphology are made in the imaging approach, the modeling approach compares the data to a family of geometric specimens, in this case having a non-uniform brightness. A statistical framework is then employed to determine whether the data is compatible with such models and to find the best-fitting model parameters.
Extending the analysis to observations from 2009-2017, scientists have shown that M87 * meets theoretical expectations. The shadow diameter of a black hole has been consistent with Einstein’s prediction of general relativity for a black hole of 6.5 billion solar masses. “In this study, we show that the general morphology or presence of an asymmetric ring, possibly persists over a period of several years,” said Janski Fellow Kaju Akiyama of the National Radio Astronomy Observatory (NRAO). MIT Hastack Observatory and contributor to the project. “Consistency in the age of multiple observations gives us more confidence than ever before about the nature and origin of the shadow of the M87 *.”
Telescopes participating in the EHT observations of M87 in 2009-2018 and the expected array in 2021. Credit: M. Wilgus, de Pace and EHT collaborate
But while the crescent-shaped diameter remained constant, the EHT team discovered that the data was surprisingly hiding: the ring would sink, and that meant big news for scientists. For the first time, they can get a glimpse of the dynamic formation of the action flow, in the state of extreme gravity, close to the event horizon of a black hole. Studying this field is key to understanding phenomena such as relative jet launches, and will allow scientists to develop new tests of the theory of general relativity.
The gas falling on a black hole heats up to billions of degrees, ionizes and becomes turbulent in the presence of a magnetic field. “Because the flow of matter is turbulent, the crescent appears to tremble over time,” Wilgus said. “Really, we’ve seen a lot of diversity there, and not all theoretical models of enthusiasm wander so much. This means that we can reject some models based on the dynamics of the observed source. “
“These early-AHT experiments provide us with a treasure trove of long-term observations that do not even match the current EHT, its remarkable imaging capabilities,” said Shape Doleman, EHT’s founding director. “When we first measured the size of the M87 in 2009, we didn’t expect it to give us the first glimpse of black hole dynamics. If you want to see black holes evolve in a decade, there is no substitute for keeping data for decades. “
EHT project scientist Jon Free Bower, research scientist at Ron Namia Sinica, Ron Stronomy and Astrophysics (ASIA) added, “Monitoring with an extended EHT array will present new images and more rich data sets for the study. We are already working to analyze data from 2018 observations obtained from an additional telescope located in Greenland. In 2021, we are planning observations with two more sites, providing exceptional imaging quality. This is a really exciting time to study black holes! ”
References: “Morphology of the M8 with the Event Horizon Telescope in 2009-2017” by Kick Wilgus, Kazunori Akiama, Lindy Blackburn, Chi-Kwan Chan, Jason Dexter, Shepard S. Doleman, Vincent L. Fish. Johnson, Thomas P. Kritchbaum, Ru-Sen Lou, Dominic W. Paes, George N. Wong, J Ge Frey C. Bower, Avery E. Broadrick, Andrew Chell, Kushik Chatterjee, Charles F. Gammy, Boris Georgieva, Kazuhi Lure Rent Loinnard, Serra Markoff, Daniel P. Marron, Richard Plumbeck, Jonathan Weintrob, Matthew Dexter, David H. MacKammahan, Melvin Wright, Anton Alberti, Vacan Albac, Everbach, Bainer, Bain, L, Mislav Balokovia, Enrico Barros, John Barrett, Dan Bintley, Wilfred Boland, Catherine L. Bunman, Michael Bremer, Christian D. Brinkrink, Roger Brycenden, Silky Britzan, Dominic Brogue, Th Thong, Feng Yuan, Ye-fi Yuan, J. Anton Zensus, Guangyao Zhao, Shan-Shan Z Ao and Xian Xu, September 23, 202 0, Astrophysical Journal.
DOI: 10.3847 / 1538-4357 / ABACDD
Event Horizon Telescope announced the first image of a black hole in the center of Radio Galaxy Messier 87 on April 10, 2019, with the international collaboration of creating a virtual Earth-shaped telescope. Supported by significant international investments, EHT combines existing telescopes using novel systems – creating a new instrument with the highest angular resolution power yet achieved.
The individual telescopes involved in the EHT collaboration are: Attackma Large Millimeter / Submillimeter Array (Alma), Attackma Pathfinder Explorer (APX), Greenland Telescope (since 2018), IRAM 30-Meter Telescope, Iram Noima Observatory (expected 2021), Kit Peak Telescope (expected 2021), James Clarkimkelp (James Clarkisk) (LMT), Submillimeter Array (SMA), Submillimeter Telescope (SMT), and South Pole Telescope (SPT).
The EHT Consortium consists of 13 stakeholder organizations; Academia Sinica Institute of Astronomy and Astrophysics, University of Arizona, The University of Chicago, East Asian Observatory, Harvard-Smithsonian Center for Astrophysics, Goethe-University Frankfurt, Institute de Radiostronomy Millimetric, Large Millimeter Telescope, Max-Planck-Institute for Radiostronosterology, Mick-Planck-Institute for Radiostronomy, Redwood University.
