Time Variability of the Neutral Iron Lines from the Sgr B2 Region and its Implication of a Past Outburst of Sgr A$^*$
| dc.creator | Inui, Tatsuya | |
| dc.creator | Koyama, Katsuji | |
| dc.creator | Matsumoto, Hironori | |
| dc.creator | Tsuru, Takeshi Go | |
| dc.date | 2008-03-11 | |
| dc.date.accessioned | 2026-07-07T09:26:09Z | |
| dc.date.available | 2026-07-07T09:26:09Z | |
| dc.description | We investigate long-term X-ray behaviors from the Sgr B2 complex using archival data of the X-ray satellites Suzaku, XMM-Newton, Chandra and ASCA. The observed region of the Sgr B2 complex includes two prominent spots in the Fe I K-$α$ line at 6.40 keV, a giant molecular cloud M 0.66$-$0.02 known as the ``Sgr B2 cloud'' and an unusual X-ray source G 0.570$-$0.018. Although these 6.40 keV spots have spatial extensions of a few pc scale, the morphology and flux of the 6.40 keV line has been time variable for 10 years, in contrast to the constant flux of the Fe XXV-K$α$ line at 6.67 keV in the Galactic diffuse X-ray emission. This time variation is mostly due to M 0.66$-$0.02; the 6.40 keV line flux declined in 2001 and decreased to 60% in the time span 1994--2005. The other spot G 0.570$-$0.018 is found to be conspicuous only in the Chandra observation in 2000. From the long-term time variability ($\sim$10 years) of the Sgr B2 complex, we infer that the Galactic Center black hole Sgr A$^*$ was X-ray bright in the past 300 year and exhibited a time variability with a period of a few years. | |
| dc.description | 13 pages, 9 figures, pasj | |
| dc.identifier | https://arxiv.org/abs/0803.1528 | |
| dc.identifier | http://arxiv.org/abs/0803.1528 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/156651 | |
| dc.subject | Astrophysics | |
| dc.title | Time Variability of the Neutral Iron Lines from the Sgr B2 Region and its Implication of a Past Outburst of Sgr A$^*$ | |
| dc.type | text |