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arXiv 1706.03243astro-ph.GA
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银河系中心2.3arcmin × 2.3arcmin中心的近红外光变研究I。变量源目录

Near-Infrared Variability Study of the Central 2.3 arcmin x 2.3 arcmin of the Galactic Centre I. Catalog of Variable Sources

Hui Dong, Rainer Schodel, Benjamin F. Williams, Francisco Nogueras-Lara, Eulalia Gallego-Cano, Teresa Gallego-Calvente, Q. Daniel Wang, Mark R. Morris, Tuan Do, Andrea Ghez

摘要:

我们使用F153 M波段(1.53微米)的银河系中心的四年基线HST/WFC 3红外观测来识别中心~ 2.3 'x2.3'视场中的变星。我们分类3845长期(从几个月到几年的时间)和76短期(几天或更短的时间)变量之间的33070颗恒星的总样本。对于后者中的36个,我们还推导了它们的周期(<3天)。我们的星表不仅证实了以前工作中发现的明亮长周期变星和大质量食双星,而且还包含了许多新发现的暗淡变星。例如,我们第一次发现了朝向银河系中心的盾牌座δ和天琴座RR型恒星,以及一颗BL Her型恒星(周期< 1.3 d)。我们交叉相关我们的目录与以前的光谱研究,发现319个变量有明确的恒星类型,如沃尔夫-拉叶,OB主序星,超巨星和渐近巨星分支星。我们使用颜色和星等来推断这些恒星的可能变量类型,而没有精确测量的周期或光谱信息。我们的结论是,大多数未分类的变量可能是食/椭球双星和II型造父变星。我们的源目录将是有价值的,为未来的研究,旨在限制银河系核星团的距离,恒星形成的历史和大量的二进制部分。

英文摘要:

We used four-year baseline HST/WFC3 IR observations of the Galactic Centre in the F153M band (1.53 micron) to identify variable stars in the central ~2.3'x2.3' field. We classified 3845 long-term (periods from months to years) and 76 short-term (periods of a few days or less) variables among a total sample of 33070 stars. For 36 of the latter ones, we also derived their periods (<3 days). Our catalog not only confirms bright long period variables and massive eclipsing binaries identified in previous works, but also contains many newly recognized dim variable stars. For example, we found δScuti and RR Lyrae stars towards the Galactic Centre for the first time, as well as one BL Her star (period < 1.3 d). We cross-correlated our catalog with previous spectroscopic studies and found that 319 variables have well-defined stellar types, such as Wolf-Rayet, OB main sequence, supergiants and asymptotic giant branch stars. We used colours and magnitudes to infer the probable variable types for those stars without accurately measured periods or spectroscopic information. We conclude that the majority of unclassified variables could potentially be eclipsing/ellipsoidal binaries and Type II Cepheids. Our source catalog will be valuable for future studies aimed at constraining the distance, star formation history and massive binary fraction of the Milky Way nuclear star cluster.

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。

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