eROSITA X射线扫描的eta Chamaeleontis集群
eROSITA X-ray scan of the eta Chamaeleontis cluster
摘要：
附近的年轻疏散星团eta Chamaeleontis在其CalPV阶段被eROSITA/SRG观测了150 k。eROSITA数据是在场扫描模式下采集的，这是一种遵循矩形网格状图案的光谱-伦琴-伽马（SRG）观察模式，此处覆盖5x 5度场，曝光深度约为5 ks。我们研究已知的成员在X射线和搜索潜在的新成员的预期分散的低质量集群人口。探测到的辐射源是通过交叉匹配X射线源与盖亚和2 MASS来识别的，年轻恒星是通过它们的X射线活动、在色星等图中的位置以及它们的天体测量和运动学特性来识别的。获得了团簇成员的X射线光度、光变曲线和光谱，并与以前的X射线数据进行了比较。其他成员检索的文献结果被用来验证我们的新成员候选人在观察领域。我们确定X射线属性几乎所有已知的eta Cha成员，并确定五个额外的恒星系统，显示基本相同的特性，但更分散。其中4个先前被提议为潜在成员;我们的X射线研究支持这一状态。根据它们的空间分布，预计在我们调查的天空区域之外还有更多的成员。这些被确认的恒星系统很可能属于被抛出的晕群，这使得eta Cha星团的成员总数至少达到23个。
英文摘要：
The nearby young open cluster eta Chamaeleontis has been observed by eROSITA/SRG during its CalPV phase for 150 ks. The eROSITA data were taken in the field-scan mode, an observing mode of Spectrum-Roentgen-Gamma (SRG) that follows a rectangular grid-like pattern, here covering a 5x5 deg field with an exposure depth of about 5 ks. We study the known members in X-rays and search for potential new members of the anticipated dispersed low-mass cluster population. Detected sources were identified by cross-matching X-ray sources with Gaia and 2MASS, and young stars were identified by their X-ray activity, the position in the color-magnitude diagram, and by their astrometric and kinematic properties. X-ray-luminosities, light curves, and spectra of cluster members were obtained and compared with previous X-ray data. Literature results of other member searches were used to verify our new member candidates in the observed field. We determine X-ray properties of virtually all known eta Cha members and identify five additional stellar systems that show basically identical characteristics, but are more dispersed. Four of them were previously proposed as potential members; this status is supported by our X-ray study. Based on their spatial distribution, further members are expected beyond the sky region we surveyed. The identified stellar systems very likely belong to the ejected halo population, which brings the total number of eta Cha cluster members to at least 23.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
