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Related papers: Radiative Models of Sgr A* from GRMHD Simulations

200 papers

Sgr A* represents a unique laboratory for the detailed study of accretion processes around a low-luminosity supermassive black hole (SMBH). Recent X-ray observations have allowed for spatially resolved modeling of the emission from the…

High Energy Astrophysical Phenomena · Physics 2018-11-28 Ren-Yi Ma , Shawn R. Roberts , Ya-Ping Li , Q. Daniel Wang

The interplay between supermassive black holes (SMBHs) and their environments is believed to command an essential role in galaxy evolution. The majority of these SMBHs are in the radiative inefficient accretion phase where this interplay…

High Energy Astrophysical Phenomena · Physics 2016-12-30 Shawn R. Roberts , Yan-Fei Jiang , Q. Daniel Wang , Jeremiah P. Ostriker

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…

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

Recent observations by the Event Horizon Telescope (EHT) of supermassive black holes M87* and Sgr A* offer valuable insights into their spacetime properties and astrophysical conditions. Utilizing a library of model images (~2 million for…

High Energy Astrophysical Phenomena · Physics 2024-09-25 A. I. Yfantis , S. Zhao , R. Gold , M. Mościbrodzka , A. E. Broderick

In accretion-based models for Sgr A* the X-ray, infrared, and millimeter emission arise in a hot, geometrically thick accretion flow close to the black hole. The spectrum and size of the source depend on the black hole mass accretion rate…

High Energy Astrophysical Phenomena · Physics 2015-06-04 Monika Moscibrodzka , Hotaka Shiokawa , Charles F. Gammie , Joshua C. Dolence

We investigate radiatively inefficient accretion flow models for Sgr A*, the supermassive black hole in our Galactic Center, in light of new observational constraints. Confirmation of linear polarization in the submm emission argues for…

Astrophysics · Physics 2009-11-07 Feng Yuan , Eliot Quataert , Ramesh Narayan

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

Sagittarius A* is a compact radio source at the Galactic center, powered by accretion of fully ionized plasmas into a supermassive black hole. However, the radio emission cannot be produced through the thermal synchrotron process by a…

High Energy Astrophysical Phenomena · Physics 2009-04-02 Kyle W. Martin , Siming Liu , Chris Fragile , Cong Yu , Chris L. Fryer

Recent high resolution observations of the Galactic center black hole allow for direct comparison with accretion disk simulations. We compare two-temperature synchrotron emission models from three dimensional, general relativistic…

High Energy Astrophysical Phenomena · Physics 2010-10-26 Jason Dexter , Eric Agol , P. Chris Fragile , Jonathan C. McKinney

Recent advances in general relativistic magnetohydrodynamic simulations have expanded and improved our understanding of the dynamics of black-hole accretion disks. However, current simulations do not capture the thermodynamics of electrons…

High Energy Astrophysical Phenomena · Physics 2015-06-23 Chi-Kwan Chan , Dimitrios Psaltis , Feryal Ozel , Ramesh Narayan , Aleksander Sadowski

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

Radiatively inefficient accretion flows (RIAFs) are believed to power supermassive black holes (SMBH) in the underluminous cores of galaxies. Such black holes are typically accompanied by flat-spectrum radio cores indicating the presence of…

High Energy Astrophysical Phenomena · Physics 2014-10-08 Monika Moscibrodzka , Heino Falcke , Hotaka Shiokawa , Charles F. Gammie

We use the public code ebhlight to carry out 3D radiative general relativistic magnetohydrodynamics (GRMHD) simulations of accretion onto the supermassive black hole in M87. The simulations self-consistently evolve a frequency-dependent…

High Energy Astrophysical Phenomena · Physics 2021-09-08 Philippe Z. Yao , Jason Dexter , Alexander Y. Chen , Benjamin R. Ryan , George N. Wong

We calculate the "observed at infinity" image and spectrum of the accretion structure in Sgr A*, by modelling it as an optically thin, constant angular momentum ion torus in hydrodynamic equilibrium. The physics we consider includes a…

Astrophysics of Galaxies · Physics 2013-02-19 Odele Straub , Frederic H. Vincent , Marek A. Abramowicz , Eric Gourgoulhon , Thibaut Paumard

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…

The observed spectral energy distribution of an accreting supermassive black hole typically forms a power-law spectrum in the Near Infrared (NIR) and optical wavelengths, that may be interpreted as a signature of accelerated electrons along…

High Energy Astrophysical Phenomena · Physics 2018-04-18 Jordy Davelaar , Monika Moscibrodzka , Thomas Bronzwaer , Heino Falcke

We present axisymmetric numerical simulations of radiatively inefficient accretion flows onto black holes combining general relativity, magnetohydrodynamics, self-consistent electron thermodynamics, and frequency-dependent radiation…

High Energy Astrophysical Phenomena · Physics 2017-08-09 Benjamin R. Ryan , Sean M. Ressler , Joshua C. Dolence , Alexander Tchekhovskoy , Charles F. Gammie , Eliot Quataert

We summarize recent observations and modeling of the brightest Sgr A* flare to be observed simultaneously in (near)-infrared and X-rays to date. Trying to explain the spectral characteristics of this flare through inverse Compton mechanisms…

We explore the variability properties of long, high cadence GRMHD simulations across the electromagnetic spectrum using an efficient, GPU-based radiative transfer algorithm. We focus on both disk- and jet-dominated simulations with…

High Energy Astrophysical Phenomena · Physics 2015-10-21 Chi-kwan Chan , Dimitrios Psaltis , Feryal Ozel , Lia Medeiros , Daniel Marrone , Aleksander Sadowski , Ramesh Narayan