NO CONFIRMED NEW ISOLATED NEUTRON STARS IN THE SDSS DATA RELEASE 4
NO CONFIRMED NEW ISOLATED NEUTRON STARS IN THE SDSS DATA RELEASE 4
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SDSS 数据发布 4 中没有确认新的孤立中子星
DOI：
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发表时间：
2011
期刊：
影响因子：
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通讯作者：
W. Voges
中科院分区：
文献类型：
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作者：
M. Agüeros;B. Posselt;S. Anderson;P. Rosenfield;F. Haberl;L. Homer;B. Margon;Emily Newsom;W. Voges
我们报告了从ROSAT全天巡天（RASS）和斯隆数字巡天（SDSS）数据发布4的相关性中确定的候选x射线明亮，无线电安静的孤立中子星（ins）的后续观测。我们获得了钱德拉x射线天文台13个候选天体的曝光，以便在光学空白的RASS误差圈内精确定位x射线发射源。这些观察结果排除了12个目标作为良好的INS候选者。我们讨论了xmm -牛顿、双子座北天文台和阿帕奇角天文台对剩余候选者的后续观测。我们认为这个天体可能是河外源，具有异常高的对数（fX/fopt） ~ 2.4。我们还使用Popov等人的种群综合模型的更新版本来估计SDSS Data Release 7足迹中ras检测到的INSs数量。我们发现，这些模型在SDSS成像的11,000 deg2中预测了~ 3-4个INSs，这与调查足迹内已知的INSs数量一致。此外，我们对SDSS足迹中确定的四个新候选INS的分析表明，它们不太可能被确认为INS；总之，这些结果表明，从RASS和SDSS的进一步相关性中不太可能发现新的INSs。
We report on follow-up observations of candidate X-ray-bright, radio-quiet isolated neutron stars (INSs) identified from correlations of the ROSAT All-Sky Survey (RASS) and the Sloan Digital Sky Survey (SDSS) Data Release 4 in Agüeros et al. We obtained Chandra X-ray Observatory exposures for 13 candidates in order to pinpoint the source of X-ray emission in optically blank RASS error circles. These observations eliminated 12 targets as good INS candidates. We discuss subsequent observations of the remaining candidate with XMM-Newton, the Gemini North Observatory, and the Apache Point Observatory. We identify this object as a likely extragalactic source with an unusually high log (fX/fopt) ∼ 2.4. We also use an updated version of the population synthesis models of Popov et al. to estimate the number of RASS-detected INSs in the SDSS Data Release 7 footprint. We find that these models predict ∼3–4 INSs in the 11,000 deg2 imaged by SDSS, which is consistent with the number of known INSs that fall within the survey footprint. In addition, our analysis of the four new INS candidates identified in the SDSS footprint implies that they are unlikely to be confirmed as INSs; together, these results suggest that new INSs are not likely to be found from further correlations of the RASS and SDSS.