标题： 星系团Abell 3571中一个可能的潮汐瓦解事件 显示英文标题

标题： A candidate tidal disruption event in the Galaxy cluster Abell 3571

摘要： 潮 disruption 事件是星系核暂时活动的可能来源，可以被视为星系中心存在超大质量黑洞的良好标志。 一个新X射线源偶然被ROSAT在对星系团A3571的PSPC指向观测中发现。 鉴于该目标在后续探测中的强烈流量衰减，我们研究了潮 disruption 场景作为事件可能解释的可能性。 我们使用ROSAT、XMM-Newton和Chandra对X射线暂现源的演化进行了长达约13年的跟踪观测。 我们还在ESO/MPI 2.2米望远镜上使用GROND获得了7波段光学/NIR测光数据。 我们报告了与Abell 3571星系团成员LEDA 095953关联的ROSAT源的X射线流量非常大的衰减。 我们测量的最大0.3-2.4 keV亮度为Log(L_X)=42.8 erg s^-1。 源的高状态至少持续了150 ks，之后L_X以~t^-2的速度下降。 最亮时期的光谱与温度kT ~0.12 keV的黑体一致。 此事件在10年内释放的总能量估计为Delta_E>2x10^50 erg。 我们将此事件解释为太阳型恒星被星系中心超大质量黑洞（即~10^7 M_sun）潮 disruption 的结果。 显示英文摘要

摘要： Tidal disruption events are possible sources of temporary nuclear activity in galactic nuclei and can be considered as good indicators of the existence of super massive black holes in the centers of galaxies. A new X-ray source has been serendipitously detected with ROSAT in a PSPC pointed observation of the galaxy cluster A3571. Given the strong flux decay of the object in subsequent detections, the tidal disruption scenario is investigated as possible explanationof the event. We followed up the evolution of the X-ray transient with ROSAT, XMM-Newton and Chandra for a total period of ~13 years. We also obtained 7-band optical/NIR photometry with GROND at the ESO/MPI 2.2m telescope. We report a very large decay of the X-ray flux of ROSAT source identified with the galaxy LEDA 095953 a member of the cluster Abell 3571. We measured a maximum 0.3-2.4 keV luminosity Log(L_X)=42.8 erg s^-1. The high state of the source lasted at least 150 ks, afterwards L_X declined as ~t^-2. The spectrum of the brightest epoch is consistent with a black body with temperature kT ~0.12 keV. The total energy released by this event in 10 yr was estimated to be Delta_E>2x10^50 erg. We interpret this event as a tidal disruption of a solar type star by the central supermassive black hole (i.e. ~10^7 M_sun) of the galaxy.