ROSAT HRI observations of the Local Group galaxies IC 10, NGC 147 and NGC 185
ROSAT HRI observations of the Local Group galaxies IC 10, NGC 147 and NGC 185
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ROSAT HRI 对本星系群 IC 10、NGC 147 和 NGC 185 的观测
DOI：
10.1093/mnras/291.4.709
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发表时间：
1997
影响因子：
4.8
通讯作者：
Paul W. Hodge
中科院分区：
文献类型：
--
作者：
W. Brandt;M. Ward;M. Ward;A. Fabian;Paul W. Hodge;Paul W. Hodge
本文报道了用ROSAT高分辨率成象仪（HRI）对IC 10、NGC 147和NGC 185进行的尖X射线观测。这是三个本星系群星系，以前从未在X射线领域详细研究过。IC 10是离我们银河系最近的星暴星系，NGC 147和NGC 185是M31的伴星。我们发现了一个与IC 10相一致的可变X射线源。这个辐射源位于一个巨大的非热辐射泡的中心附近，它与IC 10中的一颗发射线星星的位置重合，IC 10被归类为WN型沃尔夫-拉叶星星。我们证明，一个混乱的前景或背景源是不可能的。X射线源可能是IC 10中的X射线双星，它可能是Wolf-Rayet +黑洞双星。该源的平均和最大0.1- 2.5 keV各向同性光度约为2和4倍10^{38} erg/s。我们在NGC 147或NGC 185的中心区域没有发现任何来源。我们对它们的中心X射线发射设置了上限，并列出了与它们的外部范围一致的所有X射线源。我们还提出了第一个X射线探测的充分研究的Algol型二进制TV Cas和W UMa型二进制BH Cas，这两个偶然观察到在我们的IC 10指向。
We report on pointed X-ray observations of IC 10, NGC 147 and NGC 185 made with the ROSAT High Resolution Imager (HRI). These are three Local Group galaxies that have never been previously studied in detail in the X-ray regime. IC 10 is the closest starburst galaxy to our own Galaxy, and NGC 147 and NGC 185 are companions to M31. We have discovered a variable X-ray source coincident with IC 10. The source is located near the centre of a large, non-thermal bubble of radio emission, and it is positionally coincident with an emission line star in IC 10 which has been classified as a WN type Wolf-Rayet star. We demonstrate that a confusing foreground or background source is improbable. The X-ray source is probably an X-ray binary in IC 10, and it may be a Wolf-Rayet + black hole binary. The source has mean and maximum 0.1--2.5 keV isotropic luminosities of about 2 and 4 times 10^{38} erg/s. We do not detect any sources in the central regions of NGC 147 or NGC 185. We place upper limits on their central X-ray emission, and we list all X-ray sources coincident with their outer extents. We also present the first X-ray detections of the well-studied Algol-type binary TV Cas and the W UMa-type binary BH Cas, which were both serendipitously observed during our IC 10 pointing.