English
Related papers

Related papers: Microlensing Black Hole Shadows

200 papers

The effect of stars on the lensing properties of the supermassive black hole in the Galactic Center is similar to the effect of planets on microlensing by a star. We show that the dense stellar cluster around SgrA* increases by factors of a…

Astrophysics · Physics 2009-10-31 Tal Alexander , Abraham Loeb

The need for a consistent quantum evolution for black holes has led to proposals that their semiclassical description is modified not just near the singularity, but at horizon or larger scales. If such modifications extend beyond the…

High Energy Astrophysical Phenomena · Physics 2018-04-25 Steven B. Giddings , Dimitrios Psaltis

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

We investigate constraints on the distribution of dark matter in the neighbourhood of the Galactic centre that may eventually be attained with the high-resolution Event Horizon Telescope (EHT). The shadow of a black hole in vacuum is used…

Astrophysics of Galaxies · Physics 2013-08-15 Thomas Lacroix , Joseph Silk

The hypothesis that classical scalar fields could constitute dark matter on galactic and cosmic scales has garnered significant interest. In scenarios where supermassive black holes (SMBHs) form through the accretion of matter onto black…

General Relativity and Quantum Cosmology · Physics 2025-03-31 J. C. Acevedo-Muñoz , F. D. Lora-Clavijo , A. Cruz-Osorio

The study of astrophysical phenomena like black hole shadows is an effective approach to properly understand the modified gravity and explore its validity. Motivated by recent astrophysical observations, we consider a black hole (BH) in…

General Relativity and Quantum Cosmology · Physics 2025-03-20 Khadije Jafarzade , Zeynab Bazyar , Mubasher Jamil

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 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

We show that at any given time, the Galactocentric black hole Sgr A* is expected to be microlensing N(lens)=1.7 bulge stars if the threshold of detectability of the fainter image is K(thr)=21, and about N(lens)=8 sources if K(thr)=23. The…

Astrophysics · Physics 2009-11-06 Julio Chaname , Andrew Gould , Jordi Miralda-Escude

Observations of the black hole in the center of the Milky Way with the Event Horizon Telescope at 1.3 mm have revealed a size of the emitting region that is smaller than the size of the black-hole shadow. This can be reconciled with the…

High Energy Astrophysical Phenomena · Physics 2015-06-22 Dimitrios Psaltis , Ramesh Narayan , Vincent L. Fish , Avery E. Broderick , Abraham Loeb , Sheperd S. Doeleman

General Relativity predicts that the emission close to a black hole must be lensed by its strong gravitational field, illuminating the last photon orbit. This results in a dark circular area known as the black hole 'shadow'. The Event…

Instrumentation and Methods for Astrophysics · Physics 2016-09-02 Leonid Benkevitch , Kazunori Akiyama , Rusen Lu , Shepherd Doeleman , Vincent Fish

The LIGO-Virgo gravitational-wave (GW) observation unveiled the new population of black holes (BHs) that appears to have an extended mass spectrum up to around $70M_\odot$, much heavier than the previously-believed mass range ($\sim…

Astrophysics of Galaxies · Physics 2021-03-26 Satoshi Toki , Masahiro Takada

The Event Horizon Telescope has produced resolved images of the supermassive black holes Sgr A* and M87*, which present the largest shadows on the sky. In the next decade, technological improvements and extensions to the array will enable…

The shadows cast by non-rotating and rotating modified gravity (MOG) black holes are determined by the two parameters mass $M$ and angular momentum $J=Ma$. The sizes of the shadows cast by the spherically symmetric static Schwarzschild-MOG…

General Relativity and Quantum Cosmology · Physics 2015-03-26 J. W. Moffat

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

The Event Horizon Telescope (EHT) collaboration unveiled event-horizon-scale images of the supermassive black holes (SMBHs) M87* and Sgr A*, revealing a dark brightness depression, namely the black hole shadow, whose shape and size may…

General Relativity and Quantum Cosmology · Physics 2023-07-27 Misba Afrin , Sushant G. Ghosh

The compact dark objects with very large masses residing at the centres of galaxies are believed to be black holes. Due to the gravitational lensing effect, they would cast a shadow larger than their horizon size over the background, whose…

Astrophysics · Physics 2008-11-26 Lei Huang , Mike Cai , Zhi-Qiang Shen , Feng Yuan

The presence of a bright "photon ring" surrounding a dark "black hole shadow" has been discussed as an important feature of the observational appearance of emission originating near a black hole. We clarify the meaning and relevance of…

High Energy Astrophysical Phenomena · Physics 2019-07-17 Samuel E. Gralla , Daniel E. Holz , Robert M. Wald

The Event Horizon Telescope (EHT), a global submillimeter wavelength very long baseline interferometry array, unveiled event-horizon-scale images of the supermassive black hole M87* as an asymmetric bright emission ring with a diameter of $…

General Relativity and Quantum Cosmology · Physics 2020-05-12 Rahul Kumar , Sushant G. Ghosh

Thanks for the releasing image of supermassive black holes (BHs) by the event horizon telescope (EHT) at the heart of the $M87$ galaxy. After the discovery of this mysterious object, scientists paid attention to exploring the BH shadow…

General Relativity and Quantum Cosmology · Physics 2023-03-01 Xiao-Xiong Zeng , M. Israr Aslam , Rabia Saleem
‹ Prev 1 2 3 10 Next ›