CHANDRA IDENTIFICATION OF 26 NEW BLACK HOLE CANDIDATES IN THE CENTRAL REGION OF M31
CHANDRA IDENTIFICATION OF 26 NEW BLACK HOLE CANDIDATES IN THE CENTRAL REGION OF M31
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钱德拉 (Chandra) 识别 M31 中央区域 26 个新黑洞候选者
DOI：
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发表时间：
2013
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通讯作者：
S. S. Murray
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作者：
R. Barnard;Michael R. Garcia;S. S. Murray;S. S. Murray
我们之前已经在M31中确定了10个M31黑洞候选者（BHC），仅从它们的X射线特性。它们表现出“硬态”发射光谱，在X射线双星（XB）中，当亮度超过爱丁顿10%时，它们包含一颗中子星星（NS）或黑洞，亮度明显超过NS阈值。其中9个与球状星团（GC）有关;因此，它们最有可能是低质量的X射线双星;本次调查包括8个。我们最近发现，通过结构函数的长期0.5-4.5千电子伏的变异性的XBs的分析，使我们能够从活动星系核分离XBs，即使发射光谱往往是相似的，这使我们能够搜索BHC外的GC。我们利用152个钱德拉观测数据，在距离M31核（M31*）20′的范围内，确定了26个新的BHC（12个强BHC，14个可能BHC）; XMM-牛顿观测增强了我们的一些分类。其中，7个出现在M31* 的100英寸以内;这支持了这样的理论，即该区域通过与GC中观察到的类似的动态过程经历了增强的XB产生。我们已经找到了一个参数空间，我们的BHCs是从银河系NS二进制文件分离：我们表明，模拟硬态光谱与磁盘黑体+黑体模型产生的参数，位于NS二进制文件，以这种方式建模所占用的空间之外。我们的BHC都位于NS参数空间内的概率是103 × 10−29。
We have previously identified 10 M31 black hole candidates (BHCs) in M31 from their X-ray properties alone. They exhibit “hard state” emission spectra that are seen at luminosities ≲10% Eddington in X-ray binaries (XBs) containing a neutron star (NS) or black hole, at luminosities that significantly exceed the NS threshold. Nine of these are associated with globular clusters (GCs); hence, these are most likely low mass X-ray binaries; eight are included in this survey. We have recently discovered that analysis of the long term 0.5–4.5 keV variability of XBs via structure functions allows us to separate XBs from active galactic nuclei, even though the emission spectra are often similar; this has enabled us to search for BHCs outside of GCs. We have identified 26 new BHCs (12 strong, 14 plausible) within 20′ of the M31 nucleus (M31*), using 152 Chandra observations spaced over ∼13 yr; some of our classifications were enhanced with XMM-Newton observations. Of these, seven appear within 100″ of M31*; this supports the theory suggesting that this region experiences enhanced XB production via dynamical processes similar to those seen in GCs. We have found a parameter space where our BHCs are separated from Galactic NS binaries: we show that modeling a simulated hard state spectrum with a disk blackbody + blackbody model yields parameters that lie outside the space occupied by NS binaries that are modeled this way. The probability that our BHCs all lie within the NS parameter space is ∼3 × 10−29.