English
Related papers

Related papers: Black Hole Parameter Estimation from Its Shadow

200 papers

In recent years, the evidence for the existence of an ultra-compact concentration of dark mass associated with the radio source Sgr A* in the Galactic Center has become very strong. However, an unambiguous proof that this object is indeed a…

Astrophysics · Physics 2009-10-31 Heino Falcke , Fulvio Melia , Eric Agol

The half opening angle of a Kerr black-hole shadow is always equal to (5+-0.2)GM/Dc^2, where M is the mass of the black hole and D is its distance from the Earth. Therefore, measuring the size of a shadow and verifying whether it is within…

High Energy Astrophysical Phenomena · Physics 2015-12-02 Dimitrios Psaltis , Feryal Ozel , Chi-Kwan Chan , Daniel P. Marrone

We present the first Event Horizon Telescope (EHT) images of M87, using observations from April 2017 at 1.3 mm wavelength. These images show a prominent ring with a diameter of ~40 micro-as, consistent with the size and shape of the lensed…

Astrophysics of Galaxies · Physics 2019-07-08 The Event Horizon Telescope Collaboration

The inner shadow of a black hole, as a projection of the event horizon, is regarded as a potential tool for testing gravitational theories and constraining system parameters. Whether this holds in the case of a tilted accretion disk…

General Relativity and Quantum Cosmology · Physics 2025-05-21 Shiyang Hu , Dan Li , Chen Deng

This paper analyzes the experiment presented in 2019 by the Event Horizon Telescope (EHT) Collaboration that unveiled the first image of the supermassive black hole at the center of galaxy M87. The very first question asked by the EHT…

History and Philosophy of Physics · Physics 2021-03-03 Galina Weinstein

The recent Event Horizon Telescope (EHT) observations of the M87* have led to a surge of interest in studying the shadow of black holes. Besides, investigation of time evolution and lifetime of black holes helps us to veto/restrict some…

General Relativity and Quantum Cosmology · Physics 2023-02-14 S. H. Hendi , Kh. Jafarzade , B. Eslam Panah

Several works over the past years have discussed the possibility of testing fundamental physics using Very Long Baseline Interferometry horizon-scale black hole (BH) images, such as the Event Horizon Telescope (EHT) images of M87$^*$ and…

Astrophysics of Galaxies · Physics 2022-05-31 Sunny Vagnozzi , Luca Visinelli

In a previous paper, one of us has showed that, at least in some cases, the Kerr-nature of astrophysical black hole candidates is extremely difficult to test and current techniques, even in presence of excellent data not available today,…

General Relativity and Quantum Cosmology · Physics 2014-01-28 Zilong Li , Cosimo Bambi

The study of black hole (BH) shadows provide crucial insights into the nature of strong gravitational effects and the intricate structure of the spacetime surrounding BHs. In this paper, we explore the shadow of Kerr MOG BH within a plasma…

General Relativity and Quantum Cosmology · Physics 2025-04-30 Saira Yasmin , Khadije Jafarzade , Mubasher Jamil

Four spherically symmetric but non-asymptotically flat black hole solutions surrounded with spherical dark matter distribution perceived under the minimal length scale effect is derived via the generalized uncertainty principle. Here, the…

General Relativity and Quantum Cosmology · Physics 2023-12-08 Ali Övgün , Lemuel John F. Sese , Reggie C. Pantig

In this article, we present the thermodynamic and shadow properties of rotating black holes with global monopole charge. The angular diameter of Sgr A$^{*}$ black hole is 48.7 $\pm$ 7 $\mu as$, which is 8 $kps$ far away having a mass of $M…

General Relativity and Quantum Cosmology · Physics 2025-06-04 Balendra Pratap Singh , Md Sabir Ali

The initial data from the Event Horizon Telescope (EHT) on M87$^*$, the supermassive black hole at the center of the M87 galaxy, provide direct observational information on its mass, spin, and accretion disk properties. A combination of the…

Cosmology and Nongalactic Astrophysics · Physics 2019-07-12 Hooman Davoudiasl , Peter B. Denton

We consider a Lorentz violating non-commutating Kerr-like spacetime and studied the superradiance effect and the shadow cast by the back hole. We extensively study the different aspects of the black hole associated with a generalized…

General Relativity and Quantum Cosmology · Physics 2022-04-22 Sohan Kumar Jha , Anisur Rahaman

Observations of the black hole shadow of supermassive black holes, such as Sagittarius A* at the center of our Milky Way galaxy, allow us to study the properties of black holes and the nature of strong-field gravity. According to the Kerr…

General Relativity and Quantum Cosmology · Physics 2018-11-14 Dimitry Ayzenberg , Nicolas Yunes

The images of supermassive black holes surrounded by optically-thin, radiatively-inefficient accretion flows, like those observed with the Event Horizon Telescope, are characterized by a bright ring of emission surrounding the black-hole…

High Energy Astrophysical Phenomena · Physics 2023-02-01 Ziri Younsi , Dimitrios Psaltis , Feryal Özel

The groundbreaking image of the black hole at the center of the M87 galaxy has raised questions at the intersection of observational astronomy and black hole physics. How well can the radius of a black hole shadow can be measured, and can…

General Relativity and Quantum Cosmology · Physics 2022-02-02 Adam Bauer , Alejandro Cárdenas-Avendaño , Charles F. Gammie , Nicolás Yunes

The Event Horizon Telescope (EHT) has mapped the central compact radio source of the elliptical galaxy M87 at 1.3 mm with unprecedented angular resolution. Here we consider the physical implications of the asymmetric ring seen in the 2017…

Astrophysics of Galaxies · Physics 2019-07-08 The Event Horizon Telescope Collaboration

The Event Horizon Telescope (EHT) imaging of the supermassive black holes at the centers of Messier 87 galaxy and the Milky Way galaxy marks a significant step in observing the photon rings and central brightness depression that define the…

High Energy Astrophysical Phenomena · Physics 2024-11-14 Soroush Zare , Luis M. Nieto , Xing-Hui Feng , Shi-Hai Dong , Hassan Hassanabadi

The first images of black hole shadows open new possibilities to constrain modern extended gravity theories. We present the method of shadow background calculation for black hole solutions in the form of Taylor series where $g_{11} = -…

General Relativity and Quantum Cosmology · Physics 2022-09-07 V. Prokopov , S. Alexeyev , O. Zenin

Black holes are among the most compelling predictions of general relativity (GR) and are now strongly supported by observations from gravitational-wave detectors and the Event Horizon Telescope (EHT). While standard black hole solutions…

General Relativity and Quantum Cosmology · Physics 2026-01-13 A. Errehymy , Y. Khedif , M. Daoud , Y. Myrzakulov , O. Donmez , B. Turimov