Astronomy and Astrophysics – Astrophysics
Scientific paper
2004-08-17
Astrophys.J. 615 (2004) 242-252
Astronomy and Astrophysics
Astrophysics
27 pages, 8 figures, 4 tables, accepted for ApJ
Scientific paper
10.1086/424373
The archival XMM-Newton data of the central region of M31 were analyzed for diffuse X-ray emission. Point sources with the 0.5--10 keV luminosity exceeding $\sim 4 \times 10^{35}$ erg s$^{-1}$ were detected. Their summed spectra are well reproduced by a combination of a disk black-body component and a black-body component, implying that the emission mainly comes from an assembly of luminous low-mass X-ray binaries. After excluding these point sources, spectra were accumulated over a circular region of $6\arcmin$ (1.2 kpc) centered on the nucleus. In the energy range above 2 keV, these residual spectra are understood mainly as contributions of unresolved faint sources and spill-over of photons from the excluded point sources. There is in addition a hint of a $\sim 6.6$ keV line emission, which can be produced by a hot (temperature several keV) thin-thermal plasma. Below 2 keV, the spectra involve three additional softer components expressed by thin-thermal plasma emission models, of which the temperatures are $\sim 0.6$, $\sim 0.3$, and $\sim 0.1$ keV. Their 0.5--10 keV luminosities within 6$\arcmin$ are measured to be $\sim 1.2 \times 10^{38}$ erg s$^{-1}$, $\sim 1.6 \times 10^{38}$ erg s$^{-1}$, and $\sim 4 \times 10^{37}$ erg s$^{-1}$ in the order of decreasing temperature. The archival Chandra data of the central region of M31 yielded consistent results. By incorporating different annular regions, all the three softer thermal components were confirmed to be significantly extended. These results are compared with reports from previous studies. A discussion is presented on the origin of each thermal emission component.
Kokubun Motohide
Makishima Kazuo.
Okada Yuu
Takahashi Hiromitsu
No associations
LandOfFree
XMM-Newton and Chandra Observations of the Central Region of M31 does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with XMM-Newton and Chandra Observations of the Central Region of M31, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and XMM-Newton and Chandra Observations of the Central Region of M31 will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-646540