发表机构
Princeton University; Stanford University; Tel Aviv University; Siena College; Yale University; National Astronomical Observatory of Japan; Peking University（普林斯顿大学; 斯坦福大学; 特拉维夫大学; 锡耶纳学院; 耶鲁大学; 日本国立天文台; 北京大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究通过ELVES-Dwarf项目对局域体积内39个矮星系宿主的卫星系统进行系统搜索，确认39颗卫星，其丰度分布与TNG50模拟及银河系校准模型一致，且矮星系宿主周围卫星的熄灭比例低于银河系质量宿主。
AI 中文摘要
我们介绍了矮星系局域体积卫星探测项目（ELVES-Dwarf），这是一项针对局域体积内矮星系宿主周围卫星系统的系统普查。我们的最终样本包含39个主要为孤立的宿主，其恒星质量范围为$10^{7}<M_\u2605<10^{10}\\,M_\odot$，其中32个宿主是本研究中进行的统一搜索，另外7个来自文献。我们利用Legacy Surveys的155平方度成像数据，在每个宿主的投影维里半径范围内搜索卫星候选体。我们通过Subaru/HSC、Magellan/IMACS和Gemini/GMOS成像得到的表面亮度起伏距离，结合文献中的TRGB距离和径向速度来确定卫星的成员资格。在207个候选体中，我们确认了围绕这39个宿主的39个恒星质量$M_\u2605>10^5\\,M_\odot$的卫星。在我们的基准完整性阈值$M_\u2605\gtrsim10^{5.7}\\,M_\odot$以上且投影维里半径范围内，21个宿主没有确认的卫星，10个有1个，6个有2个，2个有4个，显示出卫星丰度在宿主之间存在显著差异。总体而言，观测到的卫星丰度和恒星质量函数与宇宙学模拟TNG50以及利用银河系卫星校准的星系形成模型的预测大致一致。卫星的投影径向分布也与理论预期以及银河系质量宿主周围的卫星群一致。相比之下，矮星系宿主周围卫星的熄灭比例远低于银河系质量宿主周围的比例，这表明环境熄灭在矮星系暗晕中效率较低。ELVES-Dwarf提供了第一个大型、同质、经距离确认的矮星系宿主周围卫星样本，为理解低密度环境下的星系形成与演化奠定了基础。
英文摘要
We present the Exploration of Local VolumE Satellites of Dwarf Galaxies (ELVES-Dwarf) survey, a systematic census of satellite systems around dwarf hosts in the Local Volume. Our final sample comprises 39 predominantly isolated hosts with stellar masses $10^{7}<M_\star<10^{10}\,M_\odot$, including 32 hosts searched uniformly in this work and 7 drawn from the literature. We search for satellite candidates within the projected virial radius of each host using $155~\mathrm{deg}^2$ of Legacy Surveys imaging data. We determine satellite membership using surface brightness fluctuation distances from Subaru/HSC, Magellan/IMACS, and Gemini/GMOS imaging, supplemented by literature TRGB distances and radial velocities. From 207 candidates, we confirm 39 satellites with $M_\star>10^5\,M_\odot$ around the 39 hosts. Above our fiducial completeness threshold of $M_\star\gtrsim10^{5.7}\,M_\odot$ and within the projected virial radius, 21 hosts have no confirmed satellites, 10 have one, six have two, and two have four, revealing substantial host-to-host scatter in satellite abundance. Overall, the observed satellite abundances and stellar mass functions are broadly consistent with predictions from the cosmological simulation TNG50 and galaxy formation models calibrated using Milky Way satellites. The projected radial distribution of the satellites is also consistent with theoretical expectations and with satellite populations around Milky Way-mass hosts. In contrast, the quenched fraction of satellites around dwarf hosts is substantially lower than around Milky Way-mass hosts, suggesting that environmental quenching is less efficient in dwarf halos. ELVES-Dwarf provides the first large, homogeneous, distance-confirmed sample of satellites around dwarf hosts and establishes a foundation for understanding galaxy formation and evolution in less-dense environments.
CommentsSubmitted to ApJ. Data available on the survey website: https://elves-surveys.github.io/elves-dwarf/
