Capture of a Red Giant by the Black Hole Sagittarius A* as a Possible Origin for the TeV Gamma Rays from the Galactic Center

2006 ◽  
Vol 641 (1) ◽  
pp. 288-292 ◽  
Author(s):  
Y. Lu ◽  
K. S. Cheng ◽  
Y. F. Huang
Keyword(s):  
Black Hole ◽  
Gamma Rays ◽  
Galactic Center ◽  
Sagittarius A ◽  
Red Giant ◽  
Tev Gamma Rays

scholarly journals The reflection of two past outbursts of Sagittarius A* observed by Chandra during the last decade

2013 ◽  
Vol 9 (S303) ◽  
pp. 344-348
Author(s):  
M. Clavel ◽  
R. Terrier ◽  
A. Goldwurm ◽  
M. R. Morris ◽  
G. Ponti ◽  
...  
Keyword(s):  
Black Hole ◽  
Galactic Center ◽  
Line Of Sight ◽  
High Resolution Data ◽  
The Past ◽  
Sagittarius A ◽  
Cloud Parameters ◽  
Angular Scale ◽  
Sgr A ◽  
First Time

AbstractThe supermassive black hole at the Galactic center, Sagittarius A* has experienced periods of higher activity in the past. The reflection of these past outbursts is observed in the molecular material surrounding the black hole but reconstructing its precise lightcurve is difficult since the distribution of the clouds along the line of sight is poorly constrained.Using Chandra high-resolution data collected from 1999 to 2011 we studied both the 6.4 keV and the 4–8 keV emission of the region located between Sgr A* and the Radio arc, characterizing its variations down to 15″ angular scale and 1-year time scale. The emission from the molecular clouds in the region varies significantly, showing either a 2-year peaked emission or 10-year linear variations. This is the first time that such fast variations are measured. Based on the cloud parameters, we conclude that these two behaviors are likely due to two distinct past outbursts of Sgr A* during which its luminosity rose to at least 1039 erg s−1.

scholarly journals Search for time lag in intra-day variability of Sgr A*

2013 ◽  
Vol 9 (S303) ◽  
pp. 322-323
Author(s):  
A. Miyazaki ◽  
S. S. Lee ◽  
B. W. Sohn ◽  
T. Jung ◽  
M. Tsuboi ◽  
...  
Keyword(s):  
Black Hole ◽  
Galactic Center ◽  
Time Lag ◽  
Light Curves ◽  
Time Lags ◽  
Significant Time ◽  
Sagittarius A ◽  
Receiver System ◽  
Sgr A ◽  
Plasma Blobs

AbstractWe searched the time lag between the intra-day variables (IDVs) of Sagittarius A* at 22, 43, and 86 GHz bands using the Korean VLBI Network (KVN). The time lags between the IDV flare peaks at 22 and 43 GHz are reported, and they suggest that the flare emissions come from adiabatically expanding plasma blobs, ejected close to the Galactic center black hole. We searched the time lags between light curves at 90 and 102 GHz using the Nobeyama Millimeter Array, but could not find significant time lags. In order to detect the diversity of the time lags of Sgr A* flares, we performed observations of Sgr A* in the 22, 43, and 86 GHz bands using the KVN in the winter of 2013. Because the receiver system of KVN can observe Sgr A* in these three bands simultaneously, the KVN is very useful to detect the time lags of Sgr A* flares.

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