A systematic study of X-ray variability in the ROSAT all-sky survey
A systematic study of X-ray variability in the ROSAT all-sky survey
复制标题
ROSAT 全天巡天 X 射线变异性的系统研究
DOI：
--
复制
发表时间：
2003
期刊：
影响因子：
--
通讯作者：
J. Schmitt
中科院分区：
文献类型：
--
作者：
B. Fuhrmeister;J. Schmitt
我们系统地研究了ROSAT全天巡天(RASS)X射线源之间的可变性。我们生成了大约3万个X射线点源的光曲线，探测到的X射线点源在背景高度足够高。在我们的可变性研究中，开发了不同的搜索算法，以便分别识别耀斑、周期和趋势。可变X射线源与SIMBAD、USNO-A2.0和NED数据库中的对应X射线源进行了光学识别，但很大一部分X射线源仍然没有编目的光学对应源。在1207个可变源中，767个(63.5%)与恒星有关，118个(9.8%)来自河外，10个(0.8%)与其他来源有关，312个(25.8%)不能与光学星表中的条目唯一确定。我们给出了可变X射线群的统计分析，并给出了在ROSAT全天巡天中探测到的一些突出的X射线可变性的例子。这些来源中最突出的是白矮星，表面上看起来是单一的，但仍显示出周期性的变化。在BLLac 1E1757.7+7034中，已经探测到了许多来自迄今未被识别的耀斑恒星的耀斑以及长期变化。
We present a systematic search for variability among the ROSAT All-Sky Survey (RASS) X-ray sources. We gen- erated lightcurves for about 30 000 X-ray point sources detected sufficiently high above background. For our variability study different search algorithms were developed in order to recognize flares, periods and trends, respectively. The variable X-ray sources were optically identified with counterparts in the SIMBAD, the USNO-A2.0 and NED data bases, but a significant part of the X-ray sources remains without cataloged optical counterparts. Out of the 1207 sources classified as variable 767 (63.5%) were identified with stars, 118 (9.8%) are of extragalactic origin, 10 (0.8%) are identified with other sources and 312 (25.8%) could not uniquely be identified with entries in optical catalogs. We give a statistical analysis of the variable X-ray population and present some outstanding examples of X-ray variability detected in the ROSAT all-sky survey. Most prominent among these sources are white dwarfs, apparently single, yet nevertheless showing periodic variability. Many flares from hitherto unrecognised flare stars have been detected as well as long term variability in the BL Lac 1E1757.7+7034.