X-ray monitoring of optical novae in M 31 from July 2004 to February 2005
X-ray monitoring of optical novae in M 31 from July 2004 to February 2005
复制标题
2004年7月至2005年2月对M 31光学新星的X射线监测
DOI：
--
复制
发表时间：
2006
期刊：
影响因子：
--
通讯作者：
Stella Seitz
中科院分区：
文献类型：
--
作者：
W. Pietsch;F. Haberl;G. Sala;H. Stiele;K. Hornoch;A. Riffeser;J. Fliri;Ralf Bender;S. Buhler;V. Burwitz;Jochen Greiner;Stella Seitz
语境。根据 ROSAT 和早期 XMM-Newton 和 Chandra 观测，光学新星最近被确定为 M 31 中主要的超软 X 射线源。目标。本文报告了基于档案钱德拉 HRC-I和ACIS-I以及2004年7月至2005年2月获得的星系中心区域的XMM-牛顿观测结果，寻找M 31中光学新星的X射线对应物的方法。我们系统地确定了 2003 年 11 月至 X 射线覆盖范围结束期间爆发的所有已知光学新星的对应物的 X 射线亮度或上限。此外，我们还确定了四颗较早爆发的新星的对应物的 X 射线亮度。结果。为了与 X 射线数据进行比较，我们根据我们自己的新星搜索程序和文献中报告的所有新星创建了 M 31 中的光学新星目录。我们收集了所有已知的属性，并按照 CBAT 方案对新星进行命名。在 X 射线光学爆发后的一年内，我们检测到了 34 颗新星中的 11 颗。虽然对于 11 颗新星，我们检测到超软源阶段的结束，但有 7 颗新星在爆发后超过 1200、1600、1950、2650、3100、3370 和 3380 天仍然明亮。一颗新星被发现在爆发后 50 天开启，另一颗新星则在爆发后 200 天开启。三颗新星意外地在光学爆发后 50 天内开始出现短暂的 X 射线爆发，仅持续两到三个月。几个新星的 X 射线发射可以通过硬度比和/或 X 射线光谱或通过将 HRC-I 计数率与 ACIS-I 计数率或上限进行比较来表征为超软。结论。超软 X 射线检测到的光学新星数量远高于之前的估计 (>$30\%$)。我们使用 X 射线光变曲线来估计白矮星和喷射物的燃烧质量。
Context. Optical novae have recently been identified as the major class of supersoft X-ray sources in M 31 based on ROSAT and early XMM-Newton and Chandra observations. Aims. This paper reports on a search for X-ray counterparts of optical novae in M 31 based on archival Chandra HRC-I and ACIS-I as well as XMM-Newton observations of the galaxy center region obtained from July 2004 to February 2005. Methods. We systematically determine X-ray brightness or upper limit for counterparts of all known optical novae with outbursts between November 2003 to the end of the X-ray coverage. In addition, we determine the X-ray brightnesses for counterparts of four novae with earlier outbursts. Results. For comparison with the X-ray data we created a catalogue of optical novae in M 31 based on our own nova search programs and on all novae reported in the literature. We collected all known properties and named the novae consistently following the CBAT scheme. We detect eleven out of 34 novae within a year after the optical outburst in X-rays. While for eleven novae we detect the end of the supersoft source phase, seven novae are still bright more than 1200, 1600, 1950, 2650, 3100, 3370 and 3380 d after outburst. One nova is detected to turn on 50 d, another 200 d after outburst. Three novae unexpectedly showed short X-ray outbursts starting within 50 d after the optical outburst and lasting only two to three months. The X-ray emission of several of the novae can be characterized as supersoft from hardness ratios and/or X-ray spectra or by comparing HRC-I count rates with ACIS-I count rates or upper limits. Conclusions. The number of detected optical novae at supersoft X-rays is much higher than previously estimated (>$30\%$). We use the X-ray light curves to estimate the burned masses of the White Dwarf and of the ejecta.