Ultraluminous X-ray source populations in normal galaxies: a preliminary survey with Chandra
Ultraluminous X-ray source populations in normal galaxies: a preliminary survey with Chandra
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DOI：
10.1046/j.1365-8711.2003.06802.x
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发表时间：
2003-05
影响因子：
4.8
通讯作者：
P. Humphrey;G.Fabbiano;M. Elvis;M. Church;M. Birmingham;UK.;H. C. F. Astrophysics;Cambridge University;Poland
中科院分区：
文献类型：
--
作者：
P. Humphrey;G.Fabbiano;M. Elvis;M. Church;M. Birmingham;UK.;H. C. F. Astrophysics;Cambridge University;Poland
本文介绍了利用联合收割机对13个正常星系中的超亮X射线源（ULX）进行钱德拉巡天的结果。检出22个ULX，即Lx> 1 × 1039 ergs - 1（L10），检出39个其它来源，Lx> 5 × 1038 ergs- 1（L5）。我们还使用径向强度分布从样品中去除扩展源。大多数源没有延伸，这对于典型的距离将发射区域大小限制为小于50 pc。X射线颜色-颜色图和光谱拟合结果进行了检查的指示剂的ULX性质。在较亮光源的情况下，光谱拟合通常需要双分量模型。只有在少数情况下，色图或光谱拟合才能提供黑洞性质的证据。我们没有发现与恒星质量相关的证据，但是，有一个很强的相关性与星星的形成所示的60 μm的流量，在以前的研究中发现。
We present results of a Chandra survey of the ultraluminous X-ray sources (ULX) in 13 normal galaxies, in which we combine source detection with X-ray flux measurement. 22 ULX were detected, i.e. with L x > 1 x 10 3 9 ergs - 1 (L 1 0 ) and 39 other sources were detected with L x > 5 × 10 3 8 erg s - 1 (L 5 ). We also use radial intensity profiles to remove extended sources from the sample. The majority of sources are not extended, which for a typical distance constrains the emission region size to less than 50 pc. X-ray colour-colour diagrams and spectral fitting results were examined for indicators of the ULX nature. In the case of the brighter sources, spectral fitting generally requires two-component models. In only a few cases do colour-colour diagrams or spectral fitting provide evidence of a black hole nature. We find no evidence of a correlation with stellar mass, however, there is a strong correlation with star formation as indicated by the 60-μm flux as found in previous studies.