TY - JOUR
T1 - On the comparison of AGN with GRMHD simulations
T2 - I. Sgr A
AU - Anantua, Richard
AU - Ressler, Sean
AU - Quataert, Eliot
N1 - Funding Information:
This work was supported in part by NSF grants AST 13-33612 and AST 1715054, Chandra theory grant TM7-18006X from the Smithsonian Institution, and a Simons Investigator award from the Simons Foundation. This work was made possible by computing time granted by UC Berkeley on the Savio cluster. RA carried out part of this work supported by the Alliance for Graduate Education and the Professorate (AGEP) and the Simons Foundation and the remainder of this work at the Black Hole Initiative at Harvard University, which is supported by a grant from the John Templeton Foundation. RA is also supported by the NSF MSIP grant no. AST-1440254. SR was supported in part by the NASA Earth and Space Science Fellowship and the Gordon and Betty Moore Foundation through grant no. GBMF7392 during part of the duration of this work. We all thank the scientific editor’s thorough and incisive comments, which greatly improved the overall quality of this work.
Funding Information:
This work was supported in part by NSF grants AST 13-33612 and AST 1715054, Chandra theory grant TM7-18006X from the Smithsonian Institution, and a Simons Investigator award from the Simons Foundation. This work was made possible by computing time granted by UC Berkeley on the Savio cluster. RA carried out part of this work supported by the Alliance for Graduate Education and the Professorate (AGEP) and the Simons Foundation and the remainder of this work at the Black Hole Initiative at Harvard University, which is supported by a grant from the John Templeton Foundation. RA is also supported by the NSFMSIP grant no. AST-1440254. SR was supported in part by the NASA Earth and Space Science Fellowship and the Gordon and Betty Moore Foundation through grant no. GBMF7392 during part of the duration of this work. We all thank the scientific editor's thorough and incisive comments, which greatly improved the overall quality of this work.
Publisher Copyright:
© 2020 The Author(s).
PY - 2020/3/1
Y1 - 2020/3/1
N2 - We present models of Galactic Centre emission in the vicinity of Sagittarius A∗ that use parametrizations of the electron temperature or energy density. These models include those inspired by two-temperature general relativistic magnetohydrodynamic (GRMHD) simulations as well as jet-motivated prescriptions generalizing equipartition of particle and magnetic energies. From these models, we calculate spectra and images and classify them according to their distinct observational features. Some models produce morphological and spectral features, e.g. image sizes, the sub-mm bump, and low-frequency spectral slope compatible with observations. Models with spectra consistent with observations produce the most compact images, with the most prominent, asymmetric photon rings. Limb-brightened outflows are also visible in many models. Of all the models we consider, that which represents the current data the best is one in which electrons are relativistically hot when magnetic pressure is larger than the thermal pressure, but cold (i.e. negligibly contributing to the emission) otherwise. This work is part of a series also applying the 'observing' simulations methodology to near-horizon regions of supermassive black holes in M87 and 3C 279.
AB - We present models of Galactic Centre emission in the vicinity of Sagittarius A∗ that use parametrizations of the electron temperature or energy density. These models include those inspired by two-temperature general relativistic magnetohydrodynamic (GRMHD) simulations as well as jet-motivated prescriptions generalizing equipartition of particle and magnetic energies. From these models, we calculate spectra and images and classify them according to their distinct observational features. Some models produce morphological and spectral features, e.g. image sizes, the sub-mm bump, and low-frequency spectral slope compatible with observations. Models with spectra consistent with observations produce the most compact images, with the most prominent, asymmetric photon rings. Limb-brightened outflows are also visible in many models. Of all the models we consider, that which represents the current data the best is one in which electrons are relativistically hot when magnetic pressure is larger than the thermal pressure, but cold (i.e. negligibly contributing to the emission) otherwise. This work is part of a series also applying the 'observing' simulations methodology to near-horizon regions of supermassive black holes in M87 and 3C 279.
KW - Accretion, accretion discs
KW - Black hole physics
KW - MHD
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U2 - 10.1093/mnras/staa318
DO - 10.1093/mnras/staa318
M3 - Article
AN - SCOPUS:85087157162
SN - 0035-8711
VL - 493
SP - 1404
EP - 1418
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
IS - 1
ER -