Flares from the Supermassive Black Hole Sgr A*

by Xi Lin (Shanghai Astronomical Observatory)

Tuesday 28 Mar 2023, 14:00 → 15:00 Asia/Shanghai

TDLI

Abstract

High-resolution near infrared observations with GRAVITY instrument have revealed rapid orbital motions of a hot spot around
Sgr A*, the supermassive black hole in our Galactic center, during its three bright flares. The projected distances of the spot to the black hole seems to increase with time. The values of distance, combined with the measured orbiting time, imply that the spot is rotating with a super-Keplerian velocity. Previously we have proposed a “CME” model for the flares by analogy with the coronal mass ejection model in solar physics. We apply the model to the interpretation of the GRAVITY results by calculating the dynamics of the ejected flux rope, the evolution of the magnetic field and the energy distribution of accelerated electrons, and the radiation of the system. We find that the model can well explain the observed light curve of the flares, the time-dependent distance and the super-Keplerian motion of the hot spot.

Biography

Xi Lin now is a Ph. D. Student of Shanghai Astronomical Observatory (SHAO) , his major is Astrophysics, Advisor: Prof. Feng Yuan

Education background: Sichuan University (SCU), B.S., Physics

 

Research Interests:

Black hole accretion physics

Particle acceleration process

GRMHD simulation and GRRT calculation

Chair

Mizuno Yosuke

Division

Astronomy and Astrophysics

Other information

Place: N630

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Meeting ID: 235-661-558