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Related papers: Sgr A* near-infrared flares from reconnection even…

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Sgr A* exhibits flares in the near-infrared and X-ray bands, with the luminosity in these bands increasing by factors of $10-100$ for $\approx 60$ minutes. One of the models proposed to explain these flares is synchrotron emission of…

High Energy Astrophysical Phenomena · Physics 2022-02-16 Nicolas Scepi , Jason Dexter , Mitchell C. Begelman

Context: Recent near-infrared polarization measurements of SgrA* show that its emission is significantly polarized during flares and consists of a non- or weakly polarized main flare with highly polarized sub-flares. The flare activity…

Astrophysics · Physics 2009-11-11 L. Meyer , A. Eckart , R. Schoedel , W. J. Duschl , K. Muzic , M. Dovciak , V. Karas

The emission from Sgr A*, the supermassive black hole in the Galactic Center, shows order of magnitude variability ("flares") a few times a day that is particularly prominent in the near-infrared (NIR) and X-rays. We present a…

The Galactic center black hole candidate Sgr A* is the best target for studies of low-luminosity accretion physics, including with near-infrared and submillimeter wavelength long baseline interferometry experiments. Here we compare images…

Sagittarius A* (Sgr A*), the supermassive black hole at the center of the Milky Way, undergoes large-amplitude near-infrared (NIR) flares that can coincide with the continuous rotation of the NIR emission region. One promising explanation…

High Energy Astrophysical Phenomena · Physics 2024-04-18 Arpiar Avetis Grigorian , Jason Dexter

Sagittarius A*, the supermassive black hole at the center of our galaxy, exhibits episodic near-infrared flares. The recent monitoring of three such events by the GRAVITY instrument has shown that some flares are associated with orbital…

High Energy Astrophysical Phenomena · Physics 2023-04-05 N. Aimar , A. Dmytriiev , F. H. Vincent , I. El Mellah , T. Paumard , G. Perrin , A. Zech

Context. Magnetically arrested disks are among the most suitable candidates for describing the gas accretion and observed emission in the vicinity of supermassive black holes. Aims. This work aims to provide a direct correlation between the…

High Energy Astrophysical Phenomena · Physics 2025-04-02 Eleni Antonopoulou , Argyrios Loules , Antonios Nathanail

Low-luminosity supermassive and stellar-mass black holes (BHs) may be embedded in a collisionless and highly magnetized plasma. They show non-thermal flares indicative of efficient dissipative processes in the vicinity of the BH. During NIR…

High Energy Astrophysical Phenomena · Physics 2023-09-13 I. El Mellah , B. Cerutti , B. Crinquand

Recent observations of SgrA* by the GRAVITY instrument have astrometrically tracked infrared flares (IR) at distances of $\sim 10$ gravitational radii ($r_g$). In this paper, we study a model for the flares based on 3D general relativistic…

High Energy Astrophysical Phenomena · Physics 2021-02-03 O. Porth , Y. Mizuno , Z. Younsi , C. M. Fromm

High-resolution observations with GRAVITY-VLTI instrument have provided abundant information about the flares in Sgr A*, the supermassive black hole in our Galactic center, including the time-dependent location of the centroid (a "hot…

High Energy Astrophysical Phenomena · Physics 2024-05-28 Lin Xi , Yuan Feng

Sagittarius~A$^*$, the supermassive black hole at the center of our galaxy, exhibits flares across various wavelengths, yet their origins remain elusive. We performed 3D two-temperature General Relativistic Magnetohydrodynamic (GRMHD)…

High Energy Astrophysical Phenomena · Physics 2025-07-18 Hong-Xuan Jiang , Yosuke Mizuno , Indu K. Dihingia , Feng Yuan , Xi Lin , Christian M. Fromm , Antonios Nathanail , Ziri Younsi

In general relativistic magneto-hydrodynamic (GRMHD) simulations, accreted magnetic flux on the black hole horizon episodically decays, during which magnetic reconnection heats up the plasma near the horizon, potentially powering…

High Energy Astrophysical Phenomena · Physics 2023-09-26 He Jia , Bart Ripperda , Eliot Quataert , Christopher J. White , Koushik Chatterjee , Alexander Philippov , Matthew Liska

We have performed near-infrared monitoring observations of Sgr A*, the Galactic center radio source associated with a supermassive black hole, with the near-infrared camera CIAO and the 36-element adaptive optics system on the Subaru…

The recent detection of a three-hour X-ray flare from Sgr A* by Chandra provides very strong evidence for a compact emitting region near this supermassive black hole at the Galactic center. Sgr A*'s mm/sub-mm spectrum and polarimetric…

Astrophysics · Physics 2009-11-07 Siming Liu , Fulvio Melia

Recent measurements of stellar orbits provide compelling evidence that the compact radio source Sagittarius A* at the Galactic Centre is a 3.6-million-solar-mass black hole. Sgr A* is remarkably faint in all wavebands other than the radio…

Astrophysics · Physics 2009-11-10 R. Genzel , R. Schoedel , T. Ott , A. Eckart , T. Alexander , F. Lacombe , D. Rouan , B. Aschenbach

The Galactic Center black hole Sgr A* shows significant variability and flares in the submillimeter, infrared, and X-ray wavelengths. Owing to its exquisite resolution in the IR bands, the GRAVITY experiment for the first time spatially…

High Energy Astrophysical Phenomena · Physics 2021-08-18 David Ball , Feryal Özel , Pierre Christian , Chi-Kwan Chan , Dimitrios Psaltis

Infrared observations of Sgr A* probe the region close to the event horizon of the black hole at the Galactic center. These observations can constrain the properties of low-luminosity accretion as well as that of the black hole itself. The…

The supermassive black hole Sgr A* at the center of our galaxy produces repeating near-infrared flares that are observed by ground and space based instruments. This activity has been simulated in the past with Magnetically Arrested Disk…

High Energy Astrophysical Phenomena · Physics 2024-09-11 I. Dimitropoulos , A. Nathanail , M. Petropoulou , I. Contopoulos , C. M. Fromm

Sgr A* is considered to be a massive black hole at the Galactic center and is known to be variable in radio, millimeter, near-IR and X-rays. Recent multi-wavelength observing campaigns show a simultaneous X-ray and near-IR flare, as well as…

We study the time-variable linear polarisation of Sgr A* during a bright NIR flare observed with the GRAVITY instrument on July 28, 2018. Motivated by the time evolution of both the observed astrometric and polarimetric signatures, we…

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