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Related papers: Bright X-ray flares from Sgr A*

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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

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

The source of emission from Sgr A*, the supermassive black hole at the Galactic Center, is still unknown. Flares and data from multiwavelength campaigns provide important clues about the nature of Sgr A* itself. Here we attempt to constrain…

Astrophysics of Galaxies · Physics 2015-05-14 Dipankar Maitra , Sera Markoff , Heino Falcke

We report on the results of new simulations of near-infrared (NIR) observations of the Sagittarius A* (Sgr A*) counterpart associated with the super-massive black hole at the Galactic Center. The observations have been carried out using the…

We report the first time-series of broadband infrared (IR) color measurements of Sgr A*, the variable emission source associated with the supermassive black hole at the Galactic Center. Using the laser and natural guide star AO systems on…

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

The fluorescent X-ray emission from neutral iron in the molecular clouds (Sgr B) indicates that the clouds are being irradiated by an external X-ray source. The source is probably associated with the Galactic central black hole (Sgr A*),…

High Energy Astrophysical Phenomena · Physics 2012-07-11 Yun-Wei Yu , K. S. Cheng , D. O. Chernyshov , V. A. Dogiel

For a decade now, evidence has accumulated that giant molecular clouds located within the central molecular zone of our Galaxy reflect X-rays coming from past outbursts of the supermassive black hole Sgr A*. However, the number of…

High Energy Astrophysical Phenomena · Physics 2018-02-28 Dimitri Chuard , Régis Terrier , Andrea Goldwurm , Maïca Clavel , Simona Soldi , Mark R. Morris , Gabriele Ponti , Michael Walls , Maria Chernyakova

The center of our Galaxy hosts the best constrained supermassive black hole in the universe, Sagittarius A* (Sgr A*). Its mass and distance have been accurately determined from stellar orbits and proper motion studies, respectively, and its…

High Energy Astrophysical Phenomena · Physics 2015-06-17 Heino Falcke , Sera Markoff

The center of our galaxy hosts Sagittarius~A*, a supermassive compact object of $\sim 4.3\times 10^6$ solar masses, usually associated with a black hole. Nevertheless, black holes possess a central singularity, considered unphysical, and an…

High Energy Astrophysical Phenomena · Physics 2026-04-29 Nicolas Aimar , João Luís Rosa , Hanna Liis Tamm , Paulo Garcia

(Abridged) Sgr A$^\star$ is the electromagnetic counterpart of the accreting supermassive black hole in the Galactic center. Its emission is variable in the near-infrared (NIR) and X-ray wavelengths on short timescales. The physical origin…

High Energy Astrophysical Phenomena · Physics 2024-10-15 Maria Petropoulou , Gabriele Ponti , Giovanni Stel , Apostolos Mastichiadis

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…

We analyze the two brightest Chandra X-ray flares detected from Sagittarius A*, with peak luminosities more than 600 x and 245 x greater than the quiescent X-ray emission. The brightest flare has a distinctive double-peaked morphology ---…

Sgr A* exhibits flaring in the infrared several times each day, occasionally accompanied by flaring in X-rays. The infrared flares are believed to arise through synchrotron emission from a transient population of accelerated electrons. The…

Astrophysics of Galaxies · Physics 2010-07-13 Mark Wardle

The X-ray mission Chandra has observed a dramatic X-ray flare -- a brightening by a factor of 50 for only three hours -- from Sgr A*, the Galactic Center supermassive black hole. Sgr A* has never shown variability of this amplitude in the…

Astrophysics · Physics 2009-11-07 Sera Markoff , Heino Falcke , Feng Yuan , Peter L. Biermann

We report the detection of the two-dimensional structure of the radio source associated with the Galactic Center black hole, Sagittarius A*, obtained from Very Long Baseline Array (VLBA) observations at a wavelength of 7mm. The intrinsic…

Sagittarius A* exhibits frequent flaring activity across the electromagnetic spectrum. Signatures of an orbiting hot spot have been identified in the polarized millimeter wavelength light curves observed with ALMA in 2017 immediately after…

High Energy Astrophysical Phenomena · Physics 2024-03-29 A. I. Yfantis , M. A. Mościbrodzka , M. Wielgus , J. T. Vos , A. Jimenez-Rosales

The center of our Galaxy hosts a supermassive black hole, Sagittarius (Sgr) A*. Young, massive stars within 0.5 pc of SgrA* are evidence of an episode of intense star formation near the black hole a few Myr ago, which might have left behind…

Here we report on recent near-infrared observations of the Sgr A* counterpart associated with the super-massive ~ 4x10^6 M_sun black hole at the Galactic Center. We find that the May 2007 flare shows the highest sub-flare contrast observed…

The recent detection of a 3-hr X-ray flare by the Chandra Observatory has raised the possibility of enhanced emission over a broad range of wavelengths from Sgr A*, the suspected 2.6 x 10^6 solar mass black hole at the Galactic Center,…

Astrophysics · Physics 2009-11-07 S. D. Hornstein , A. M. Ghez , A. Tanner , M. Morris , E. E. Becklin , P. Wizinowich