The discrete X-ray source population in M31
The discrete X-ray source population in M31
复制标题
M31 中的离散 X 射线源群
DOI：
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发表时间：
1991
期刊：
影响因子：
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通讯作者：
G. Fabbiano
中科院分区：
文献类型：
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作者：
G. Trinchieri;G. Fabbiano
本文分析了M31的爱因斯坦成像观测结果。探测到108个独立的X射线源，在M31的距离上，其亮度范围从5 x 10 exp 36 ergs/s到10 exp 38 ergs/s以上。其中14个光源的亮度足以对X射线数据进行光谱拟合。除了科卢拉、雷亚莱和佩雷斯（1990）已经报道的两个来源外，还发现了14个来源在爱因斯坦的观测中有所不同。与先前的报道相反，没有实质性的差异被发现之间的X射线源的光度分布在隆起和在磁盘。在中心区域的X射线发射的等高线图，并与光学轮廓的表面亮度的径向分布进行了比较。据推测，相对于恒星的含量，该盘在X射线下相对较暗。隆起源的空间分布进行了比较，光学新星和发射状图像的隆起。这些比较限制了低质量X射线双星形成的模型。
Results of an analysis of the complete set of Einstein imaging observations of M31 are reported. One-hundred-eight individual X-ray sources are detected, with (0.2-4.0 keV) luminosities ranging from 5 x 10 exp 36 ergs/s to above 10 exp 38 ergs/s at the distance of M31. Fourteen of these sources are luminous enough to perform a spectral fit of the X-ray data. Fourteen sources are found to vary between Einstein observations, in addition to the two sources already reported by Collura, Reale, and Peres (1990). Contrary to earlier reports, no substantial difference is found between the luminosity distributions of X-ray sources in the bulge and in the disk. Contour maps of the X-ray emission in the central region is presented, and the radial distribution of the surface brightness is compared with the optical profiles. It is inferred that the disk is relatively underluminous in X-rays, relative to the stellar content. The spatial distribution of bulge sources is compared with that of optical novae and with emission-like images of the bulge. These comparisons constrain models of the formation of low-mass X-ray binaries.