Constraining the Accretion Flow in Sgr A* by General Relativistic Dynamical and Polarized Radiative Modeling

TL;DR

This paper models the polarized sub-mm spectra of Sgr A* using general relativistic magneto hydrodynamic simulations and radiative transfer, fitting observed data to constrain accretion flow parameters.

Contribution

It introduces a self-consistent method combining GRMHD simulations with polarized radiative transfer to analyze Sgr A* spectra.

Findings

Estimated inclination angle range: 42-75 degrees

Derived mass accretion rate: (1.4-7.0)×10^{-8} Msun/yr

Electron temperature at 6M: (3-4)×10^{10} K

Abstract

We briefly summarize the method of simulating Sgr A* polarized sub-mm spectra from the accretion flow and fitting the observed spectrum. The dynamical flow model is based on three-dimensional general relativistic magneto hydrodynamic simulations. Fully self-consistent radiative transfer of polarized cyclo-synchrotron emission is performed. We compile a mean sub-mm spectrum of Sgr A* and fit it with the mean simulated spectra. We estimate the ranges of inclination angle theta=42-75deg, mass accretion rate Mdot=(1.4-7.0)*10^{-8}Msun/yr, and electron temperature Te=(3-4)*10^{10}K at 6M. We discuss multiple caveats in dynamical modeling, which must be resolved to make further progress.