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Related papers: A Relativistic Disk in Sagittarius A*

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The massive black hole at the Galactic Centre is known to be variable in radio, millimeter, near-IR and X-rays. We investigate the physical processes responsible for the variable observed emissions from the compact radio source Sgr A*. We…

High Energy Astrophysical Phenomena · Physics 2016-02-05 E. M. Howard

In this article we summarise and discuss the infrared, radio, and X-ray emission from the supermassive black hole in the Galactic Centre, SgrA*. We include new results from near-infrared polarimetric imaging observations obtained on May…

Astrophysics · Physics 2008-11-26 S. Trippe , T. Paumard , T. Ott , S. Gillessen , F. Eisenhauer , F. Martins , R. Genzel

The hypothesis that radiation of Sgr A* is caused by accretion onto a supermassive compact object without the events horizon is studied. The main equations of the accretion and a relativistic equation of the trasfer radiation are obtained.…

Astrophysics · Physics 2007-05-23 L. Verozub

Sagittarius A* (Sgr A*) is the variable radio, near-infrared (NIR), and X-ray source associated with accretion onto the Galactic center black hole. We present an analysis of the most comprehensive NIR variability dataset of Sgr A* to date:…

The supermassive black hole at the Galactic center, Sagittarius A*, has experienced periods of higher activity in the past. The reflection of these past outbursts is observed in the molecular material surrounding the black hole but…

High Energy Astrophysical Phenomena · Physics 2014-10-21 Maïca Clavel , R. Terrier , A. Goldwurm , M. R. Morris , G. Ponti , S. Soldi , G. Trap

Proper motions and radial velocities of luminous infrared stars in the galactic center have provided strong evidence for a dark mass of 2.5 million solar masses in the central 0.05 pc of the galaxy. The leading hypothesis for this mass is a…

Astrophysics · Physics 2009-10-31 D. C. Backer , R. A. Sramek

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

The radio source Sagittarius A* (Sgr A*), is thought to be a supermassive black hole located at the centre of our Galaxy, that is accreting gas from the surrounding region. Using the high inferred accretion rates, however, standard…

Astrophysics · Physics 2007-05-23 Rohan Mahadevan

Studies of the inner few parsecs at the Galactic Centre provide evidence of a supermassive black hole, associated with the unusual, variable radio and infrared source Sgr A*. Our major aim is the study and analysis of the physical processes…

High Energy Astrophysical Phenomena · Physics 2016-02-03 E. M. Howard

We present high-resolution multiwavelength radio continuum images of the region within 150$"$ of Sgr A*, revealing a number of new extended features and stellar sources in this region. First, we detect a continuous 2" east-west ridge of…

Astrophysics of Galaxies · Physics 2016-03-16 F. Yusef-Zadeh , M. Wardle , R. Schödel , D. A. Roberts , W. Cotton , H. Bushouse , R. Arendt , M. Royster

We present the results of a 3.3-year project to monitor the flux density of Sagittarius A* at 2.0, 1.3, and 0.7 cm with the VLA. The fully calibrated light curves for Sgr A* at all three wavelengths are presented. Typical errors in the flux…

Astrophysics · Physics 2009-11-10 R. M. Herrnstein , J. -H. Zhao , G. C. Bower , W. M. Goss

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…

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…

We have performed monitoring observations of the 3-mm flux density toward the Galactic Center compact radio source Sgr A* with the Australia Telescope Compact Array since 2005 October. Careful calibrations of both elevation-dependent and…

Astrophysics of Galaxies · Physics 2009-07-22 Juan Li , Zhi-Qiang Shen , Atsushi Miyazaki , Lei Huang , R. J. Sault , Makoto Miyoshi , Masato Tsuboi , Takahiro Tsutsumi

Sagittarius A* (Sgr A*) -- the supermassive black hole (SMBH) in the center of our galaxy -- has been observed in most of the electromagnetic spectrum, from radio to X-rays. Diffuse gamma-ray emission has been observed around Sgr A* and a…

High Energy Astrophysical Phenomena · Physics 2021-09-08 Fabio Cafardo , Rodrigo Nemmen

Very strong evidence suggests that Sagittarius A*, a compact radio source at the center of the Milky Way, marks the position of a super massive black hole. The proximity of Sgr A* in combination with its mass makes its apparent event…

Astrophysics of Galaxies · Physics 2009-06-23 Vincent L. Fish , Sheperd S. Doeleman

Sub milli-arcsecond astrometry and imaging of the black hole Sgr A* at the Galactic centre may become possible in the near future at infrared and sub-millimetre wavelengths. Motivated by observations of short-term infrared and X-ray…

Astrophysics · Physics 2009-11-13 Avery E. Broderick , Abraham Loeb

We report on 85-101 GHz light curves of the Galactic Center supermassive black hole, Sagittarius A* (Sgr A*), observed in April 2017 with the Atacama Large Millimeter/submillimeter Array (ALMA). This study of high-cadence full-Stokes data…

High Energy Astrophysical Phenomena · Physics 2024-07-24 Maciek Wielgus , Sara Issaoun , Ivan Marti-Vidal , Razieh Emami , Monika Moscibrodzka , Christiaan D. Brinkerink , Ciriaco Goddi , Ed Fomalont

The relatively rapid spatial and temporal variability of the X-ray radiation from some molecular clouds near the Galactic center shows that this emission component is due to the reflection of X-rays generated by a source that was luminous…

High Energy Astrophysical Phenomena · Physics 2015-06-16 Maïca Clavel , R. Terrier , A. Goldwurm , M. R. Morris , G. Ponti , S. Soldi , G. Trap

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
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