We propose a strategy for searching for isolated stellar mass black holes in the solar neighborhood with the Sloan Digital Sky Survey. Due to spherical accretion of the inter-stellar medium and the ambient magnetic field, an isolated black hole is expected to emit a blended, thermal synchrotron spectrum with a roughly flat peak from the optical down to the far infra-red. We find that the Sloan Survey will be able to detect isolated black holes, in the considered mass range of 1--100M_{\odot}, out to a few hundred parsecs, depending on the local conditions of the ISM. We also find that the black holes are photmetrically distinguishable from field stars and they have a photometry similar to QSOs. They can be further singled out from QSO searches because they have a featureless spectrum with no emission lines. The Sloan Survey will likely find hundreds of objects that meet these criteria, and to further reduce the number of candidates, we suggest other selection criteria such as infra-red searches and proper motion measurements. Estimates indicate that dozens of black holes may exist out to a few hundred parsecs. If no black hole candidates are found in this survey, important limits can be placed on the local density of black holes and the halo fraction in black holes, especially for masses greater than about 20 M_{\odot}.
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机译:我们提出了一种通过斯隆数字天空调查在太阳附近搜寻孤立的恒星质量黑洞的策略。由于星际介质和周围磁场的球形积聚,预计一个孤立的黑洞会发出混合的热同步加速器光谱,从光学到远红外的峰值大致平坦。我们发现,根据ISM的当地条件,斯隆调查将能够检测到孤立的黑洞,该黑洞的质量范围为1--100M _ {\ odot},可达数百秒秒。我们还发现黑洞与野外恒星在光度学上可以区分开,并且它们的光度与QSO相似。由于它们具有无谱线且没有发射谱线,因此可以从QSO搜索中进一步选择它们。斯隆问卷调查可能会找到数百个满足这些条件的物体,并且为了进一步减少候选对象的数量,我们建议使用其他选择条件,例如红外搜索和适当的运动测量。估计表明,几十个黑洞可能存在数百秒差距。如果在此调查中未找到候选黑洞,则可以对黑洞的局部密度和黑洞中的光晕分数设置重要的限制,尤其是对于质量大于约20 M _ {\ odot}的情况。
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