Multiwavelength Monitoring of Sgr A* During Chandra Observations of Multiple X-ray Flares
Abstract
Sgr A* was observed with the ACIS-I instrument on the Chandra X-Ray Observatory for 0.5 Ms during the period 22 May 2002 to 4 June 2002. Three X-ray flares with amplitudes in excess of a factor of 10 and several flares of lower amplitude were detected. The flare durations ranged from half an hour to several hours with rise and fall times of a few hundred seconds, similar to the original X-ray flare discovered with Chandra in 2000. These observations confirm that rapid X-ray flaring of Sgr A* is common. Averaging over all Chandra observations from 1999-2002, a total of 0.6 Ms, the mean rate of factor-of-10 flares is 0.6 +\- 0.3 per day. During the Chandra observations, a network of ground-based telescopes were employed for simultaneous observations for varying amounts of time and at various wavelengths: the Keck-I Telescope at 2 and 10 microns; the VLT at 2 to 5 microns; the Magellan-Baade Telescope at 10 microns; the SMA at 1 mm; the ATCA and the Owens Valley Millimeter Array at 3 mm; the VLBA at 7 mm; and the VLA at 0.7, 1.3 and 2 cm. We compare the variability properties in the X-ray and longer wavelength bands to assess models for the origin of the X-ray flares from Sgr A*. This research was supported by NASA grant NAS8-39073.
- Publication:
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American Astronomical Society Meeting Abstracts
- Pub Date:
- December 2002
- Bibcode:
- 2002AAS...201.3108B