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arXiv 2607.14584astro-ph.GA

来自快速全天空氢原子巡天(FASHI)第二数据释放(DR2)的致密高速云团目录

A Catalog of Compact High-Velocity Clouds from the FAST All-Sky HI Survey (FASHI) DR2

Jin-Long Xu, Chuan-Peng Zhang, Xiao-Lan Liu, Nai-Ping Yu, Mei Ai, Ming Zhu

AI总结:

该研究基于FASHI DR2给出192个致密高速云团目录,其中多数为新发现的超致密高速云团。这些云团在空间和运动学上集中于仙女座星系,给出了相关质量数据,约一半遵循重子塔利-费舍尔关系且未发现光学对应体,或代表富含气体、无恒星的微型晕族,为暗星系搜索提供样本。

AI中文摘要:

高速云团(HVCs),尤其是致密高速云团(CHVCs),被认为是暗物质主导的次晕的气体示踪剂,在预测的暗物质子结构和观测到的卫星星系之间提供了关键的经验联系。本文展示了一个从快速全天空氢原子巡天(FASHI)数据释放2(DR2)中识别出的192个CHVCs的新目录。其中108个是超致密高速云团(UCHVCs),大部分是新发现。发现192个CHVCs中的185个在空间和运动学上集中在仙女座星系(M31)周围,平均本地标准静止系(LSR)速度为-296.1千米/秒,表明与M31有物理关联。采用M31距离0.8百万秒差距,得出氢原子质量在1.9×10⁵到4.0×10⁶太阳质量之间,动力学质量在1.0×10⁷到6.3×10⁸太阳质量之间。大约一半的CHVCs遵循重子塔利-费舍尔关系。在泛星1号成像中,直到极限星等m_g = 22.8都未检测到光学对应体。我们得出结论,这些CHVCs可能代表了富含气体、无恒星的微型晕族,为寻找暗星系提供了一个优秀样本。

英文摘要:

High-velocity clouds (HVCs) -- especially compact HVCs (CHVCs) -- are thought to serve as gaseous tracers of dark-matter-dominated subhalos, providing a crucial empirical link between the predicted dark matter substructure and observed satellite galaxies. In this paper, we present a new catalog of 192 CHVCs identified from the FAST All-Sky HI Survey (FASHI) Data Release 2 (DR2). Among these, 108 are ultra-compact HVCs (UCHVCs), the majority of which are new discoveries. We find that 185 of the 192 CHVCs are spatially and kinematically concentrated around the Andromeda galaxy (M31), with a median LSR velocity of -296.1 km/s, suggesting physical association with M31. Adopting an M31 distance of 0.8 Mpc, we derive HI masses in the range 1.9*10^{5} to 4.0*10^{6} Msun and dynamical masses from 1.0*10^{7} to 6.3*10^{8} Msun. Approximately half of the CHVCs follow the baryonic Tully--Fisher relation. No optical counterparts are detected in Pan-STARRS1 imaging down to a limiting magnitude of m_g = 22.8. We conclude that these CHVCs likely represent a population of gas-rich, starless minihalos and provide an excellent sample for the search for dark galaxies.

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