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Related papers: Global Structure of Accretion Flows in Sgr A*

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In this paper the jet model for the supermassive black hole candidate Sgr A* in the Center of the Galaxy is reviewed. The most recent model, with a reduced set of parameters, is able to account for all major radio properties of the source:…

Astrophysics · Physics 2007-05-23 Heino Falcke

We present general relativistic magnetohydrodynamic (GRMHD) numerical simulations of the accretion flow around the supermassive black hole in the Galactic centre, Sagittarius A* (Sgr A*). The simulations include for the first time radiative…

High Energy Astrophysical Phenomena · Physics 2015-06-05 Salomé Dibi , Samia Drappeau , P. Chris Fragile , Sera Markoff , Jason Dexter

We present results of our Chandra observation with the ACIS-I instrument centered on the position of Sagittarius A* (Sgr A*), the compact nonthermal radio source associated with the massive black hole (MBH) at the dynamical center of the…

Although it is widely accepted that most galaxies have supermassive black holes (SMBHs) at their centers^{1-3}, concrete proof has proved elusive. Sagittarius A* (Sgr A*)^4, an extremely compact radio source at the center of our Galaxy, is…

Astrophysics · Physics 2009-11-13 Zhi-Qiang Shen , K. Y. Lo , M. -C. Liang , Paul T. P. Ho , J. -H. Zhao

Recent observations of the radio and NIR source Sgr A* reinforce the interpretation of the Galactic Center as a scaled down version of an AGN. The discovery of an elongated structure at 43 GHz and increasing evidence for the presence of an…

Astrophysics · Physics 2011-05-23 Heino Falcke , Karl Mannheim , Peter L. Biermann

The compact radio source at the center of our Galaxy, Sagittarius A* (Sgr A*), is the subject of intensive study as it provides a close-up view of an accreting supermassive black hole. Sgr A* provides us with a prototype of a low-luminosity…

High Energy Astrophysical Phenomena · Physics 2021-07-29 Christiaan Brinkerink , Heino Falcke , Andreas Brunthaler , Casey Law

We present the combination of dynamical accretion model based on 3D GRMHD simulations and general relativistic (GR) polarized radiative transfer. We write down the formalism of and perform the GR ray-tracing of cyclo-synchrotron radiation…

High Energy Astrophysical Phenomena · Physics 2009-12-14 Roman V. Shcherbakov , Robert F. Penna

The compact, nonthermal radio source Sgr A* at the Galactic Center appears to be coincident with a 2.6 million solar mass point-like object. Its energy source may be the release of gravitational energy as gas from the interstellar medium…

Astrophysics · Physics 2009-10-31 Robert F. Coker , Fulvio Melia

Radiatively inefficient accretion flow models have been shown to accurately account for the spectrum and luminosity observed from Sgr A* in the X-ray regime down to mm wavelengths. However, observations at a few GHz cannot be explained by…

High Energy Astrophysical Phenomena · Physics 2017-07-19 Ian Christie , Maria Petropoulou , Petar Mimica , Dimitrios Giannios

Based on Bremer et al. (2011) and Eckart et al. (2012) we report on simultaneous observations and modeling of the millimeter, near-infrared, and X-ray flare emission of the source Sagittarius A* (SgrA*) associated with the super-massive…

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 radio source Sgr A* in the Galactic center emits a polarized spectrum at millimeter and sub-millimeter wavelengths that is strongly suggestive of relativistic disk accretion onto a massive black hole. We use the well-constrained mass of…

Astrophysics · Physics 2009-11-06 Benjamin C. Bromley , Fulvio Melia , Siming Liu

The Galactic Center black hole Sgr A* is the archetypical example of an underfed massive black hole. The extremely low accretion rate can be understood in radiatively inefficient accretion flow models. Testing those models has proven to be…

Radio and mm-wavelength observations of Sagittarius A* (Sgr A*), the radio source associated with the supermassive black hole at the center of our Galaxy, show that it behaves as a partially self-absorbed synchrotron-emitting source. The…

We review the physical processes that occur at the center of the Galaxy and that are related to the supermassive black hole Sgr A* residing there. The discovery of high-velocity S0 stars orbiting Sgr A* for the first time allowed measuring…

High Energy Astrophysical Phenomena · Physics 2015-12-10 V. I. Dokuchaev , Yu. N. Eroshenko

Sagittarius A* (Sgr A*) is a strong, compact radio source believed to be powered by a super-massive black hole at the galactic center. Extinction by dust and gas in the galactic plane prevents observing it optically, but its position and…

Astrophysics of Galaxies · Physics 2023-01-18 David Gordon , Aletha de Witt , Christopher S. Jacobs

We revisit theoretical and observational constraints on geometrically-thin disk accretion in Sagittarius A* (Sgr A*). We show that the combined effects of mass outflows and electron energization in the hot part of the accretion flow can…

Astrophysics · Physics 2009-11-13 Erin J. D. Jolley , Zdenka Kuncic

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 have analyzed a comprehensive submillimeter (including new observations simultaneous with…