Candidate tidal disruption events from the XMM-Newton slew survey
Candidate tidal disruption events from the XMM-Newton slew survey
复制标题
DOI：
10.1051/0004-6361:20066072
复制
发表时间：
2006-12
影响因子：
6.5
通讯作者：
P. Esquej;R. Saxton;M. Freyberg;A. Read;B. Altieri;M. Sánchez-Portal;G. Hasinger
中科院分区：
文献类型：
--
作者：
P. Esquej;R. Saxton;M. Freyberg;A. Read;B. Altieri;M. Sánchez-Portal;G. Hasinger
上下文。近年来，从少数非活动星系观测到了巨幅X射线耀斑。这些不同寻常的现象最有可能的情况是，星系中心一个静止的超大质量黑洞使恒星发生潮汐分裂。目标。到目前为止，只观察到和证实了少数这类事件。更多事例的发现将使人们能够就潮汐扰动事件的频率、静止黑洞质量的分布及其在星系/活动星系核形成和演化等背景下的影响等性质得出一些基本结论。方法：研究方法。将XMM-牛顿旋转源星表与ROSAT PSPC全天巡天星表进行比较，已经探测到五个星系，XMM-牛顿星表相对于ROSAT PSPC上限亮度高达88倍，呈现出一种软X射线颜色。由回转观测得到的这些源的X射线光度在10^{41}-10^{44}$erg S-1的范围内，与潮汐破裂模型完全一致。该模型预测，在耀斑爆发的高峰期，耀斑的X射线光度最高可达1045erg S-1，接近黑洞的爱丁顿光度，随后通量将在数月至数年的时间尺度上衰减。为了弄清它们的性质并研究它们的动力学演化，我们对这些高度可变的天体进行了多波长的跟踪观测。结果。在这里，我们介绍了来自XMM-牛顿旋转调查的来源，这些来源可能符合潮汐破坏事件的范例。X射线和光学观测显示，其中两个天体与这一情景完全一致，另外三个来源显示出光学活动的迹象，需要在瞬变星系核现象中进行进一步研究。
Context. In recent years, giant amplitude X-ray flares have been observed from a handful of non-active galaxies. The most plausible scenario of these unusual phenomena is tidal disruption of a star by a quiescent supermassive black hole at the centre of the galaxy. Aims. Only a small number of these type of events have been observed and confirmed to date. The discovery of more cases would allow a number of fundamental conclusions to be drawn about properties such as the frequency of tidal disruption events, the distribution of quiescent black hole masses and their influence in the context of galaxy/AGN formation and evolution among others. Methods. Comparing the XMM-Newton Slew Survey Source Catalogue with the ROSAT PSPC All-Sky Survey five galaxies have been detected a factor of up to 88 brighter in XMM-Newton with respect to ROSAT PSPC upper limits and presenting a soft X-ray colour. X-ray luminosities of these sources derived from slew observations have been found in the range $10^{41}{-}10^{44}$ erg s -1 , fully consistent with the tidal disruption model. This model predicts that during the peak of the outburst, flares reach X-ray luminosities up to 10 45 erg s -1 , which is close to the Eddington luminosity of the black hole, and afterwards a decay of the flux on a time scale of months to years is expected. Multi-wavelength follow-up observations have been performed on these highly variable objects in order to disentangle their nature and to investigate their dynamical evolution. Results. Here we present sources coming from the XMM-Newton Slew Survey that could fit in the paradigm of tidal disruption events. X-ray and optical observations revealed that two of these objects are in full agreement with that scenario and three other sources that, showing signs of optical activity, need further investigation within the transient galactic nuclei phenomena.