SYNCHROTRON BLOB MODEL OF INFRARED AND X-RAY FLARES FROM SAGITTARIUS A*

被引：10

作者：

Kusunose, Masaaki ^{[1
]}

Takahara, Fumio ^{[2
]}

机构：

[1] Kwansei Gakuin Univ, Dept Phys, Sch Sci & Technol, Sanda 6691337, Japan

[2] Osaka Univ, Dept Earth & Space Sci, Grad Sch Sci, Toyonaka, Osaka 5600043, Japan

来源：

ASTROPHYSICAL JOURNAL | 2011年 / 726卷 / 01期

关键词：

acceleration of particles; black hole physics; Galaxy: center; radiation mechanisms: non-thermal; SUPERMASSIVE BLACK-HOLE; DOMINATED ACCRETION FLOW; HIGH-ENERGY EMISSION; SGR-A; GALACTIC-CENTER; GAMMA-RAYS; MILLIMETER; MULTIWAVELENGTH; DIRECTION; BLAZARS;

D O I：

10.1088/0004-637X/726/1/54

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

Sagittarius A* in the Galactic center harbors a supermassive black hole and exhibits various active phenomena. Besides quiescent emission in radio and submillimeter radiation, flares in the near-infrared (NIR) and X-ray bands are observed to occur frequently. We study a time-dependent model of the flares, assuming that the emission is from a blob ejected from the central object. Electrons obeying a power law with the exponential cutoff are assumed to be injected in the blob for a limited time interval. The flare data of 2007 April 4 were used to determine the values of model parameters. The spectral energy distribution of flare emission is explained by nonthermal synchrotron radiation in the NIR and X-ray bands. The model light curves suggest that electron acceleration is still underway during the rising phase of the flares. GeV gamma-rays are also emitted by synchrotron self-Compton scattering, although their luminosity is not strictly constrained by the current model. If the GeV emission is faint, the plasma blob is dominated by the magnetic energy density over the electron kinetic energy density. Observations in the GeV band will clarify the origin of the blob.

引用

页数：6

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