发表机构
Institute for Astronomy, University of Hawaii; Main Astronomical Observatory, National Academy of Sciences of Ukraine; Special Astrophysical Observatory, Russian Academy of Sciences; Space Telescope Science Institute; Astronomy Department, University of Maryland（夏威夷大学天体物理研究所; 乌克兰国家科学院主天文台; 俄罗斯科学院特殊天文台; 太空望远镜科学研究所; 马里兰大学天文学系）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究探讨本地空洞的不规则矮星系KKR 18的特征，发现其红巨星分支极度缺失，推断这类星系为晚到星系，缺乏古老恒星成分。
AI 中文摘要
KKR 18是位于本地空洞的一个不规则矮星系，距离9.46 Mpc，富含气体，20至100百万年前经历过活跃的恒星形成阶段。根据发射光谱，其金属丰度为太阳的4%，符合极贫金属（XMP）星系的定义。它最显著的特征是红巨星分支极度缺失，该特征与少数其他矮星系共有，据此推断这些星系缺乏古老恒星成分，被认为是晚到星系（LAG）。
英文摘要
KKR 18 is a dwarf irregular galaxy in the Local Void at a distance of 9.46 Mpc. It is gas rich and was experiencing vigorous star formation 20 - 100 Myr ago. Its metallicity is 4% of Solar from an emission spectrum, qualifying is as extremely metal poor (XMP). Its most remarkable characteristic is an extremely deficient Red Giant Branch. This feature is shared with a small number of other dwarf galaxies and it is inferred that they lack ancient stellar components. It is suggested that these are late arrival galaxies (LAG).
Comments12 pages, 13 figures. Submitted to The Astrophysical Journal
