An Inverse Compton Scattering Origin of X-Ray Flares from Sgr A*
Abstract
The X-ray and near-IR emission from Sgr A* is dominated by flaring, while a quiescent component dominates the emission at radio and submillimeter (sub-mm) wavelengths. The spectral energy distribution of the quiescent emission from Sgr A* peaks at sub-mm wavelengths and is modeled as synchrotron radiation from a thermal population of electrons in the accretion flow, with electron temperatures ranging up to ~5-20 MeV. Here, we investigate the mechanism by which X-ray flare emission is produced through the interaction of the quiescent and flaring components of Sgr A*. The X-ray flare emission has been interpreted as inverse Compton, self-synchrotron Compton, or synchrotron emission. We present results of simultaneous X-ray and near-IR observations and show evidence that X-ray peak flare emission lags behind near-IR flare emission with a time delay ranging from a few to tens of minutes. Our inverse Compton scattering modeling places constraints on the electron density and temperature distributions of the accretion flow and on the locations where flares are produced. In the context of this model, the strong X-ray counterparts to near-IR flares arising from the inner disk should show no significant time delay, whereas near-IR flares in the outer disk should show a broadened and delayed X-ray flare.
- Publication:
-
The Astronomical Journal
- Pub Date:
- July 2012
- DOI:
- 10.1088/0004-6256/144/1/1
- arXiv:
- arXiv:1203.2188
- Bibcode:
- 2012AJ....144....1Y
- Keywords:
-
- black hole physics;
- Galaxy: center;
- infrared: general;
- ISM: clouds;
- ISM: general;
- X-rays: general;
- Astrophysics - High Energy Astrophysical Phenomena
- E-Print:
- 22 pages, 6 figures, 2 tables, AJ (in press)