文章基本信息

标题：NO CONFIRMED NEW ISOLATED NEUTRON STARS IN THE SDSS DATA RELEASE 4*
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作者：Marcel A. Agüeros ; Bettina Posselt ; Scott F. Anderson 等
期刊名称：The Astronomical journal
印刷版ISSN：0004-6256
电子版ISSN：1538-3881
出版年度：2011
卷号：141
期号：6
DOI：10.1088/0004-6256/141/6/176
语种：English
出版社：American Institute of Physics
摘要：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 (f X/f opt) ~ 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.
关键词：stars: neutron Online-only material: color figure