Kavli Affiliate: Feng Yuan
| First 5 Authors: Hong-Xuan Jiang, Hong-Xuan Jiang, , ,
| Summary:
Sagittarius~A$^*$, the supermassive black hole at the center of our galaxy,
exhibits flares across various wavelengths, yet their origins remain elusive.
We performed 3D two-temperature General Relativistic Magnetohydrodynamic
(GRMHD) simulations of magnetized accretion flows initialized from multi-loop
magnetic field configuration onto a rotating black hole and conducted General
Relativistic Radiative Transfer (GRRT) calculations considering contributions
from both thermal and non-thermal synchrotron emission processes. Our results
indicate that the polarity inversion events from the multi-loop magnetic field
configurations can generate $138,rm THz$ flares consistent with observations
with the help of non-thermal emission. By tracing the intensity evolution of
light rays in GRRT calculations, we identify the precise location of the
flaring region and confirm that it originates from a large-scale polarity
inversion event. We observe time delays between different frequencies, with
lower-frequency radio flares lagging behind higher frequencies due to plasma
self-absorption in the disk. The time delay between near-infrared and 43 GHz
flares can reach up to $sim 50$ min, during which the flaring region gradually
shifts outward, becoming visible at lower frequencies. Our study confirms that
large-scale polarity inversion in a Standard And Normal Evolution (SANE)
accretion flow with a multi-loop initial magnetic configuration can be a
potential mechanism driving flares from Sgr~A$^*$.
| Search Query: ArXiv Query: search_query=au:”Feng Yuan”&id_list=&start=0&max_results=3