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Related papers: The Event Horizon Telescope: exploring strong grav…

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In this paper, we provide a first physical interpretation for the Event Horizon Telescope (EHT)'s 2017 observations of Sgr A*. Our main approach is to compare resolved EHT data at 230 GHz and unresolved non-EHT observations from radio to…

High Energy Astrophysical Phenomena · Physics 2023-11-17 The Event Horizon Telescope Collaboration

We show that interferometry can be applied to study irregular, rapidly rotating structures, as are expected in the turbulent accretion flow near a black hole. Specifically, we analyze the lagged covariance between interferometric baselines…

Instrumentation and Methods for Astrophysics · Physics 2015-11-11 Michael D. Johnson , Abraham Loeb , Hotaka Shiokawa , Andrew A. Chael , Sheperd S. Doeleman

Recent results of the event horizon-scale images of M87* and Sagittarius A* from the Event Horizon Telescope Collaboration show that strong magnetic fields are likely present around the central black holes (BHs) in these sources.…

High Energy Astrophysical Phenomena · Physics 2025-09-19 Koushik Chatterjee , Matthew Liska , Alexander Tchekhovskoy , Sera Markoff , Ramesh Narayan

In recent years, unprecedented progress has been achieved regarding black holes' observation through the electromagnetic channel. The images of the supermassive black holes M87$^{*}$ and Sgr A$^{*}$ released by the Event Horizon Telescope…

High Energy Astrophysical Phenomena · Physics 2023-10-11 Songbai Chen , Jiliang Jing , Wei-Liang Qian , Bin Wang

The next-generation Event Horizon Telescope (ngEHT) will be a significant enhancement of the Event Horizon Telescope (EHT) array, with $\sim 10$ new antennas and instrumental upgrades of existing antennas. The increased $uv$-coverage,…

Hawking's black hole area theorem can be tested by monitoring the evolution of a single black hole over time. Using current imaging observations of two supermassive black holes M87* and Sgr A* from the Event Horizon Telescope (EHT), we find…

General Relativity and Quantum Cosmology · Physics 2023-03-15 Deng Wang

The Event Horizon Telescope (EHT) collaboration recently unveiled the first image of the supermassive black hole M87*, which exhibited a ring of angular diameter $\theta_{d}=42 \pm 3 \mu as$, a circularity deviation $\Delta C \leq 0.1$, and…

General Relativity and Quantum Cosmology · Physics 2022-06-17 Misba Afrin , Sushant G. Ghosh

Event Horizon Telescope (EHT) observations at 230 GHz are combined with Very Long Baseline Interferometry (VLBI) observations at 86 GHz and high resolution Hubble Space Telescope optical observations in order to constrain the broadband…

Astrophysics of Galaxies · Physics 2017-12-13 Brian Punsly

The impressive images from the Event Horizon Telescope sharpen the conflict between our observations of gravitational phenomena and the principles of quantum mechanics. Two related scenarios for reconciling quantum mechanics with the…

General Relativity and Quantum Cosmology · Physics 2019-09-18 Steven B. Giddings

The goal of the Event Horizon Telescope (EHT) is to provide spatially resolved images of Sgr A*, the source associated with the Galactic Center black hole. Because Sgr A* varies on timescales short compared to an EHT observing campaign, it…

High Energy Astrophysical Phenomena · Physics 2017-09-06 Hotaka Shiokawa , Charles F. Gammie , Sheperd S. Doeleman

General relativity predicts that black hole images ought to display a bright, thin (and as-of-yet-unresolved) ring. This "photon ring" is produced by photons that explore the strong gravity of the black hole, flowing along trajectories that…

The concept of a new space very long baseline interferometry system named the Event Horizon Imager (EHI) has been proposed to dramatically improve black hole imaging and provide precise tests of the theory of general relativity. We…

High Energy Astrophysical Phenomena · Physics 2026-02-04 Anastasia Shlentsova , Freek Roelofs , Sara Issaoun , Jordy Davelaar , Heino Falcke

Global expansion of the Event Horizon Telescope (EHT) will see the strategic addition of antennas at new geographical locations, transforming the sensitivity and imaging fidelity of the $\lambda \sim 1$\,mm EHT array. A possible South…

Instrumentation and Methods for Astrophysics · Physics 2024-12-11 Senkhosi Simelane , Roger Deane , Athol Kemball , Roelf Botha , Roufurd Julie , Keitumetse Molamu , Adrian Tiplady , Aletha de Witt

The Event Horizon Telescope (EHT) has released analyses of reconstructed images of horizon-scale millimeter emission near the supermassive black hole at the center of the M87 galaxy. Parts of the analyses made use of a large library of…

With the advent of the Event Horizon Telescope (EHT), a millimeter/sub-millimeter very-long baseline interferometer (VLBI), it has become possible to image a handful of black holes with sub-horizon resolutions. However, these images do not…

High Energy Astrophysical Phenomena · Physics 2015-05-27 Avery E. Broderick , Abraham Loeb , Mark J. Reid

Recently, the Event Horizon Telescope (EHT) achieved the realization of an image of the supermassive black hole $\textrm{Sgr~A}^\star$ showing an angular shadow diameter $\mathcal{D}= 48.7 \pm 7\mu as$ and the fractional deviation…

General Relativity and Quantum Cosmology · Physics 2024-04-23 L. Chakhchi , H. El Moumni , K. Masmar

No. All theoretical predictions for the observational appearance of an accreting supermassive black hole, as measured interferometrically by a sparse Earth-sized array at current observation frequencies, are sensitive to many untested…

High Energy Astrophysical Phenomena · Physics 2021-01-20 Samuel E. Gralla

A long standing goal in astrophysics is to directly observe the immediate environment of a black hole with angular resolution comparable to the event horizon. Realizing this goal would open a new window on the study of General Relativity in…

The Event Horizon Telescope (EHT), a global 230 GHz VLBI array, achieves an angular resolution of ${\approx} 20\,\mu{\rm as}$, sufficient to resolve the supermassive black hole Sagittarius A* (Sgr A*). This resolution may soon enable…

Instrumentation and Methods for Astrophysics · Physics 2019-01-09 Ziyan Zhu , Michael D. Johnson , Ramesh Narayan

In light of the Event Horizon Telescope (EHT) images of the supermassive black holes $\textrm{Sgr A}^\star$ and $\textrm{M87}^\star$, we explore a potential supersymmetry suspicion within the observational data. Specifically, we investigate…

High Energy Physics - Theory · Physics 2024-09-05 L. Chakhchi , H. El Moumni , K. Masmar