Optical identification of faint X-ray sources in the core of ω Centauri

被引:17
作者
Carson, JE
Cool, AM
Grindlay, JE
机构
[1] San Francisco State Univ, Dept Phys & Astron, San Francisco, CA 94132 USA
[2] Harvard Univ, Dept Astron, Cambridge, MA 02138 USA
关键词
binaries : close; globular clusters : individual (omega Centauri); novae; cataclysmic variables; white dwarfs; X-rays : stars;
D O I
10.1086/308582
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
We present the results of a search for optical counterparts of three faint X-ray sources in the core of NGC 5139 (omega Cen) with the HST Wide Field Planetary Camera 2. Using images taken through the F656N (H alpha), F675W, and F336W filters, we have identified two stars with strong H alpha and UV excesses, one in each of two of the X-ray error circles, and a possible optical counterpart in the third. The absolute magnitudes, broadband colors, and inferred emission-line strengths of all three stars are typical of cataclysmic variables (CVs). Further comparisons of the disk properties of the two strong candidates to CVs in the held strengthen our conclusion that they are promising CV candidates.
引用
收藏
页码:461 / 466
页数:6
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