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Related papers: Modelling the black hole silhouette in Sgr A* with…

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We review results from general relativistic axisymmetric magnetohydrodynamic simulations of accretion in Sgr A*. We use general relativistic radiative transfer methods and to produce a broad band (from millimeter to gamma-rays) spectrum.…

High Energy Astrophysical Phenomena · Physics 2010-02-08 M. Moscibrodzka , C. F. Gammie , J. Dolence , H. Shiokawa , P. K. Leung

SgrA$^*$ is the supermassive black hole candidate at the center of the Galaxy and an ideal laboratory to test general relativity. Following previous work by other authors, we use the Polish doughnut model to describe an optically thin and…

General Relativity and Quantum Cosmology · Physics 2015-12-02 Nan Lin , Zilong Li , Jake Arthur , Rachel Asquith , Cosimo Bambi

Context. The properties of the accretion flow surrounding the supermassive central black hole of the Galaxy, Sgr A*, will be scrutinized by the new-generation instrument GRAVITY and the Event Horizon Telescope (EHT). Developing fast,…

High Energy Astrophysical Phenomena · Physics 2019-04-17 F. H. Vincent , M. A. Abramowicz , A. A. Zdziarski , M. Wielgus , T. Paumard , G. Perrin , O. Straub

The global structure of optically thin advection dominated accretion flows which are composed of two-temperature plasma around black holes is calculated. We adopt the full set of basic equations including the advective energy transport in…

Astrophysics · Physics 2009-10-30 T. Manmoto , S. Mineshige , M. Kusunose

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

Context. The supermassive black hole, Sagittarius (Sgr) A*, in the centre of our Galaxy has the largest angular size in the sky among all astrophysical black holes. Its shadow, assuming no rotation, spans ~ 50 microarcsec. Resolving such…

Astrophysics of Galaxies · Physics 2015-06-19 F. H. Vincent , W. Yan , O. Straub , A. A. Zdziarski , M. A. Abramowicz

High-resolution, multi-wavelength, and time-domain observations of the Galactic centre black hole candidate, Sgr A*, allow for a direct test of contemporary accretion theory. To date, all models have assumed alignment between the accretion…

High Energy Astrophysical Phenomena · Physics 2015-06-04 Jason Dexter , P. Chris Fragile

The accretion flow around the Galactic Center black hole Sagittarius A* (Sgr A*) is expected to have an electron temperature that is distinct from the ion temperature, due to weak Coulomb coupling in the low-density plasma. We present four…

High Energy Astrophysical Phenomena · Physics 2018-05-31 Andrew Chael , Michael E. Rowan , Ramesh Narayan , Michael D. Johnson , Lorenzo Sironi

We obtain estimates of Sgr A* accretion flow and black hole parameters by fitting polarized sub-mm observations with spectra computed using three-dimensional (3D) general relativistic (GR) magnetohydrodynamical (MHD) (GRMHD) simulations.…

High Energy Astrophysical Phenomena · Physics 2015-05-19 Roman V. Shcherbakov , Robert F. Penna , Jonathan C. McKinney

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

Using flow models based on axisymmetric general relativistic magnetohydrodynamics (GRMHD) simulations, we construct radiative models for sgr A*. Spectral energy distributions that include the effects of thermal synchrotron emission and…

High Energy Astrophysical Phenomena · Physics 2014-11-20 Monika Moscibrodzka , Charles F. Gammie , Joshua C. Dolence , Hotaka Shiokawa , Po Kin Leung

We present a numerical method which evolves a two-temperature, magnetized, radiative, accretion flow around a black hole, within the framework of general relativistic radiation magnetohydrodynamics. As implemented in the code KORAL, the gas…

High Energy Astrophysical Phenomena · Physics 2017-01-18 A. Sadowski , M. Wielgus , R. Narayan , D. Abarca , J. C. McKinney , A. Chael

We present numerical simulations of the axisymmetric accretion of a massive magnetized plasma torus on a rotating black hole. We use a realistic equation of state, which takes into account neutrino cooling and energy loss due to nucleus…

High Energy Astrophysical Phenomena · Physics 2014-11-20 Maxim V. Barkov , Anton N. Baushev

Sgr A* is probably the supermassive black hole being investigated most extensively due to its proximity. Several theoretical models for its steady state emission have been proposed in the past two decades. Both the radiative-inefficient…

High Energy Astrophysical Phenomena · Physics 2015-06-23 Ya-Ping Li , Feng Yuan , Q. Daniel Wang

In fully general relativity, we calculate the images of the radiatively inefficient accretion flow (RIAF) surrounding a Kerr black hole with arbitrary spins, inclination angles, and observational wavelengths. For the same initial…

High Energy Astrophysical Phenomena · Physics 2014-11-18 Ye-Fei Yuan , Xinwu Cao , Lei Huang , Zhi-Qiang Shen

The radio source Sagittarius A* (Sgr A*) is believed to be a hot, inhomogeneous, magnetized plasma flowing near the event horizon of the 3 million solar mass black hole at the galactic center. At a distance of 8000 parsecs the black hole…

Astrophysics · Physics 2008-11-26 Scott C. Noble , Po Kin Leung , Charles F. Gammie , Laura G. Book

In the last several years, a number of observing campaigns of the massive black hole Sgr A* has been carried out in order to address two important issues: one concerns the underluminous nature of Sgr A* with its bolometric luminosity being…

Astrophysics of Galaxies · Physics 2015-05-18 F. Yusef-Zadeh , M. Wardle

Images from the vicinity of the black hole horizon at the Galactic centre (Sgr A*) could be obtained in the near future with a Very Large Baseline Array of sub-millimetre telescopes. The recently observed short-term infrared and X-ray…

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

Recent millimeter-VLBI observations of Sagittarius A* (Sgr A*) have, for the first time, directly probed distances comparable to the horizon scale of a black hole. This provides unprecedented access to the environment immediately around the…

Astrophysics · Physics 2010-01-15 Avery E. Broderick , Vincent L. Fish , Sheperd S. Doeleman , Abraham Loeb

The recent detection of polarized radiation from Sgr A* requires a non-thermal electron distribution for the emitting plasma. The Faraday rotation measure must be small, placing strong limits on the density and magnetic field strength. We…

Astrophysics · Physics 2009-10-31 Eric Agol
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