FIFTY M31 BLACK HOLE CANDIDATES IDENTIFIED BY CHANDRA AND XMM-NEWTON
FIFTY M31 BLACK HOLE CANDIDATES IDENTIFIED BY CHANDRA AND XMM-NEWTON
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钱德拉和 XMM-牛顿确定的 50 个 M31 黑洞候选者
DOI：
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发表时间：
2014
期刊：
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通讯作者：
S. Murray
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文献类型：
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作者：
R. Barnard;Michael R. Garcia;F. Primini;S. Murray;S. Murray
在过去的大约五年里，我们已经从M31的x射线光谱中确定了~ 35个黑洞候选者（BHCs）。我们的BHCs在高于中子星（NS） XB的上限的光度下，表现出与x射线双星（XB）硬态一致的0.3-10 keV光谱。当我们用圆盘黑体+黑体模型建模BHC光谱并与明亮的NS xb进行比较时，我们发现BHC与NS xb占据不同的参数空间。然而，BH XBs也可能表现出热主导（TD）状态，这在NS XBs中从未见过；这种TD态最常在x射线瞬变中观察到。我们在钱德拉对M31的巡天中检查了约50个x射线瞬变，发现13个具有适合分析的光谱。我们还在球状星团B045和B375中检查了视野之外的两个BHCs。我们有42个强有力的BHCs和8个可能的BHCs，可以从进一步的观察中受益。在球状星团中的15个BHCs中，有12个与NS光谱相差bbb50 σ。由于我们分析的改进，我们将之前确定的10种合理的BHCs升级为强BHCs。在M31* 6 '范围内的33个x射线瞬变的平均最大占空比为0.13；我们估计该区域40%的xb包含黑洞吸积体。值得注意的是，我们估计BHCs贡献了90%的XBs > 1038erg s - 1。
Over approximately the last five years, we have identified ∼35 black hole candidates (BHCs) in M31 from their X-ray spectra. Our BHCs exhibited 0.3–10 keV spectra consistent with the X-ray binary (XB) hard state at luminosities that are above the upper limit for neutron star (NS) XBs. When our BHC spectra were modeled with a disk blackbody + blackbody model for comparison with bright NS XBs, we found that the BHCs inhabited a different parameter space than the NS XBs. However, BH XBs may also exhibit a thermally dominated (TD) state that has never been seen in NS XBs; this TD state is most often observed in X-ray transients. We examined the ∼50 X-ray transients in our Chandra survey of M31 and found 13 with spectra suitable for analysis. We also examined two BHCs outside the field of view of our survey in the globular clusters B045 and B375. We have 42 strong BHCs and 8 plausible BHCs that may benefit from further observation. Of our 15 BHCs in globular clusters, 12 differ from NS spectra by >5σ. Due to improvements in our analysis, we have upgraded 10 previously identified plausible BHCs to strong BHCs. The mean maximum duty cycle of the 33 X-ray transients within 6′ of M31* is 0.13; we estimate that >40% of the XBs in this region contain BH accretors. Remarkably, we estimate that BHCs contribute >90% of those XBs >1038 erg s−1.