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THE POWER OF IMAGING: CONSTRAINING THE PLASMA PROPERTIES OF GRMHD SIMULATIONS USING EHT OBSERVATIONS OF Sgr A*

Chi-Kwan Chan, Dimitrios Psaltis, Feryal Özel, Ramesh Narayan, Aleksander Sa¸dowski
2015 Astrophysical Journal  
However, when combined with the measurement of the image size of the emission using the Event Horizon Telescope, current observations rule out all models with strong funnel emission, because the funnels  ...  Our study shows that images of accretion flows with horizon-scale resolution offer a powerful tool in understanding accretion flows around black-holes and their thermodynamic properties.  ...  We thank Alexander Tchekhovskoy for providing the original derivations of the coordinate transformation used in the HARM simulations.  ... 
doi:10.1088/0004-637x/799/1/1 fatcat:7rw3zssumvc4tcklnv2sznqfmq

Studying Black Holes on Horizon Scales with VLBI Ground Arrays [article]

Lindy Blackburn, Sheperd Doeleman, Jason Dexter, José L. Gómez, Michael D. Johnson, Daniel C. Palumbo, Jonathan Weintroub, Katherine L. Bouman, Andrew A. Chael, Joseph R. Farah, Vincent Fish, Laurent Loinard, Colin Lonsdale, Gopal Narayanan (+21 others)
2019 arXiv   pre-print
The goal of these efforts is to move from imaging static horizon scale structure to dynamic reconstructions that capture the processes of accretion and jet launching in near real time.  ...  Over the coming decade, the EHT will propose to add new strategically placed VLBI elements operating at 1.3mm and 0.87mm wavelength.  ...  et al. in 2017 with the Event Horizon Telescope array.  ... 
arXiv:1909.01411v2 fatcat:ws6g5nvhp5dqlnahqtlijljx6q

SYMBA: An end-to-end VLBI synthetic data generation pipeline

F. Roelofs, M. Janssen, I. Natarajan, R. Deane, J. Davelaar, H. Olivares, O. Porth, S. N. Paine, K. L. Bouman, R. P. J. Tilanus, I. van Bemmel, H. Falcke (+8 others)
2019 Astronomy and Astrophysics  
We used SYMBA to create synthetic observations for the Event Horizon Telescope (EHT), a millimetre VLBI array, which has recently captured the first image of a black hole shadow.  ...  In our case study, these improvements allowed for a distinction between a thermal and a non-thermal GRMHD model based on salient features in reconstructed images.  ...  Deane are grateful for the support from the New Scientific Frontiers with Precision Radio Interferometry Fellowship awarded by the South African Radio Astronomy Observatory (SARAO), which is a facility  ... 
doi:10.1051/0004-6361/201936622 fatcat:dy5vw2ufo5gadowx4xypkddfku

SYMBA: An end-to-end VLBI synthetic data generation pipeline [article]

F. Roelofs, M. Janssen, I. Natarajan, R. Deane, J. Davelaar, H. Olivares, O. Porth, S. N. Paine, K. L. Bouman, R. P. J. Tilanus, I. M. van Bemmel, H. Falcke (+190 others)
2020 arXiv   pre-print
We used SYMBA to create synthetic observations for the Event Horizon Telescope (EHT), a mm VLBI array, which has recently captured the first image of a black hole shadow.  ...  In our case study, these improvements allowed for a distinction between a thermal and a non-thermal GRMHD model based on salient features in reconstructed images.  ...  This work is supported by the ERC Synergy Grant "Black-HoleCam: Imaging the Event Horizon of Black Holes" (Grant 610058). I. Natarajan and R.  ... 
arXiv:2004.01161v1 fatcat:lnqo7psa7zeytkijeftnuep2iu

The science case and challenges of space-borne sub-millimeter interferometry [article]

Leonid I. Gurvits, Zsolt Paragi, Ricardo I. Amils, Ilse van Bemmel, Paul Boven, Viviana Casasola, John Conway, Jordy Davelaar, M. Carmen Díez-González, Heino Falcke, Rob Fender, Sándor Frey (+42 others)
2022 arXiv   pre-print
Recent results in direct imaging of the vicinity of the supermassive black hole in the nucleus of the radio galaxy M87 by the millimeter VLBI system Event Horizon Telescope and various pioneering results  ...  in-depth technology trade-off studies.  ...  YYK and AVP were supported in the framework of the State project "Science" by the Ministry of Science and Higher Education of the Russian Federation under the contract 075-15-2020-778.  ... 
arXiv:2204.09144v2 fatcat:u6z5apvg6vcrphs2vmvgumhyje

Tracing a Black Hole: Probing Cosmic Darkness in Anthropocenic Times [chapter]

Jessie Beier
2021 Palgrave Studies in Education and the Environment  
AbstractIn April 2019, the Event Horizon Telescope (EHT) project released an unprecedented image of a supermassive black hole at the centre of galaxy Messier 87.  ...  The image, which shows a dark disc outlined by swirling hot gas circling the black hole's event horizon, exhibits a 55 million-year-old cosmic event in the Virgo galaxy cluster—a void of stellar mass measuring  ...  on the scale of a black hole's event horizon.  ... 
doi:10.1007/978-3-030-79622-8_3 fatcat:g7on6u7utvg23p7sp73bzrhqwi

Visible shapes of black holes M87* and SgrA* [article]

V. I. Dokuchaev, N. O. Nazarova
2020 arXiv   pre-print
A size of the dark spot on the EHT image agrees with a corresponding size of the dark event horizon silhouette in a thin accretion disk model in the case of either the high or moderate value of the black  ...  The first image of the supermassive black hole M87 *, obtained by the Event Horizon Telescope collaboration, shows the lensed dark image of the southern hemisphere of the black hole event horizon globe  ...  This study was supported in part by the Russian Foundation for Basic Research project 18-52-15001-NCNIa.  ... 
arXiv:2007.14121v1 fatcat:cy2kepitwnhnrkha5bylw7hgyq

BlackHoleCam: Fundamental physics of the galactic center

C. Goddi, H. Falcke, M. Kramer, L. Rezzolla, C. Brinkerink, T. Bronzwaer, J. R. J. Davelaar, R. Deane, M. De Laurentis, G. Desvignes, R. P. Eatough, F. Eisenhauer (+27 others)
2017 International Journal of Modern Physics D  
be resolved by upcoming VLBI experiments at mm-waves such as the Event Horizon Telescope (EHT).  ...  The third experiment aims to time a radio pulsar in tight orbit about Sgr A* using radio telescopes (including the Atacama Large Millimeter Array or ALMA).  ...  Acknowledgments This work is supported by the ERC Synergy Grant "BlackHoleCam: Imaging the Event Horizon of Black Holes" (Grant 610058).  ... 
doi:10.1142/s0218271817300014 fatcat:mcx5aa2nqfambo3bjxa6tfvx3e

Forthcoming Article

2019 Astrophysical Journal Letters  
To image and study this phenomenon, we have assembled the Event Horizon Telescope, a global very long baseline interferometry array observing at a wavelength of 1.3 mm.  ...  The asymmetry in brightness in the ring can be explained in terms of relativistic beaming of the emission from a plasma rotating close to the speed of light around a black hole.  ...  A.  ... 
doi:10.3847/2041-8213/ab0ec7 fatcat:6ci4yaeo6jer5ib5arv6mjfvxi

BlackHoleCam: Fundamental physics of the galactic center

C. Goddi, H. Falcke, M. Kramer, L. Rezzolla, C. Brinkerink, T. Bronzwaer, J. R. J. Davelaar, R. Deane, M. De Laurentis, G. Desvignes, R. P. Eatough, F. Eisenhauer (+27 others)
2017 The Fourteenth Marcel Grossmann Meeting  
Acknowledgments This work is supported by the ERC Synergy Grant "BlackHoleCam: Imaging the Event Horizon of Black Holes" (Grant 610058).  ...  We then describe current experimental and theoretical efforts of the BlackHoleCam b project, which is funded by the European Research Council (ERC) and is a partner of the Event Horizon Telescope c (EHT  ...  The motivation for this is to fully explore degeneracies between all parameters, scientific or calibration-related and so extract the maximum scientific inference from a given EHT dataset.  ... 
doi:10.1142/9789813226609_0046 fatcat:tmgn4jbnr5eetjrid4llw6mrgy

Submillimeter Array (SMA) Newsletter July 2019

Raymond Blundell
2019 Zenodo  
the Event Horizon TelescopeM87 Image 10 Mass Assembly of Stellar Systems and Their Evolution with the SMA (MASSES) 15 Star Formation Rates of Massive Molecular Clouds in the Central Molecular Zone TECHNICAL  ...  Submillimeter Array (SMA) Newsletter July 2019 Blundell, Raymond Submillimeter Array Newsletter | Number 28 | July 2019 CONTENTS 1 From the Director SCIENCE HIGHLIGHTS: 2 The SMA's Key Role in Capturing  ...  (First M87 Event Horizon Telescope Results. III.  ... 
doi:10.5281/zenodo.3344492 fatcat:pobjaw6udjakrg3frckndiskui

The Nature of Black Hole Shadows [article]

Thomas Bronzwaer, Heino Falcke
2021 arXiv   pre-print
event horizon, versus rays that do not (blocking), and ii) the increase of intensity observed in rays that travel along extended, horizon-circling paths near the boundary of the unstable-photon region  ...  We demonstrate that the black-hole shadow is a distinct phenomenon from the photon ring, and that models exist in which the former may be observed, but not the latter.  ...  For these reasons, observing the black-hole shadow was a key driver for the Event Horizon Telescope (EHT, Event Horizon Telescope Collaboration et al. 2019a) and one of its clearest predictions (Falcke  ... 
arXiv:2108.03966v1 fatcat:2xsjuysnkjfczcugjg5jsnsjq4

The current ability to test theories of gravity with black hole shadows

Yosuke Mizuno, Ziri Younsi, Christian M. Fromm, Oliver Porth, Mariafelicia De Laurentis, Hector Olivares, Heino Falcke, Michael Kramer, Luciano Rezzolla
2018 Nature Astronomy  
Upcoming sub-millimetre very-long-baseline-interferometry (VLBI) images of Sgr A* carried out by the Event-Horizon-Telescope Collaboration (EHTC) are expected to provide critical evidence for the existence  ...  Adopting the VLBI configuration from the 2017 EHTC campaign, we find that it could be extremely difficult to distinguish between BHs from different theories of gravity, thus highlighting that great caution  ...  This research is supported by the ERC synergy grant "BlackHoleCam: Imaging the Event Horizon of Black Holes" (Grant No. 610058). ZY acknowledges support from an Alexander von Humboldt Fellowship.  ... 
doi:10.1038/s41550-018-0449-5 fatcat:wzid4yc73vf4lb23ubba7ul6mi

THEZA: TeraHertz Exploration and Zooming-in for Astrophysics

Leonid I. Gurvits, Zsolt Paragi, Viviana Casasola, John Conway, Jordy Davelaar, Heino Falcke, Rob Fender, Sándor Frey, Christian M. Fromm, Cristina García Miró, Michael A. Garrett, Marcello Giroletti (+23 others)
2021 Experimental astronomy (Print)  
It also builds upon the recent success of the Earth-based Event Horizon Telescope (EHT) – the first-ever direct image of a shadow of the super-massive black hole in the centre of the galaxy M87.  ...  The main aim of the concept is to facilitate a major leap by providing researchers with orders of magnitude improvements in the resolution and dynamic range in direct imaging studies of the most exotic  ...  from the copyright holder.  ... 
doi:10.1007/s10686-021-09714-y fatcat:qhsdu7r2dnaalftzn7i4ypiyjq

PERSISTENT ASYMMETRIC STRUCTURE OF SAGITTARIUS A* ON EVENT HORIZON SCALES

Vincent L. Fish, Michael D. Johnson, Sheperd S. Doeleman, Avery E. Broderick, Dimitrios Psaltis, Ru-Sen Lu, Kazunori Akiyama, Walter Alef, Juan Carlos Algaba, Keiichi Asada, Christopher Beaudoin, Alessandra Bertarini (+60 others)
2016 Astrophysical Journal  
The Galactic Center black hole Sagittarius A* (Sgr A*) is a prime observing target for the Event Horizon Telescope (EHT), which can resolve the 1.3 mm emission from this source on angular scales comparable  ...  The median closure phase on a triangle including telescopes in California, Hawaii, and Arizona is nonzero.  ...  INTRODUCTION The Event Horizon Telescope (EHT) SagittariusA * (Sgr A * ) is located at the Galactic center and marks a dark mass of just over M 4 10 6  (Ghez et al. 2008; Gillessen et al. 2009b Gillessen  ... 
doi:10.3847/0004-637x/820/2/90 fatcat:vvswywuevbgt5ncjmwwadwxgda
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