标题： 56 个 MATLAS 低光度星系的径向速度和恒星种群特性观测结果 显示英文标题

标题： Radial velocities and stellar population properties of 56 MATLAS dwarf galaxies observed with MUSE

摘要： 矮星系在本星系群、邻近星系群和选定的星系团中已被广泛研究，这使我们对宇宙中特定位置的它们的整体恒星和动力学特性有了可靠的认识。 对这些特性的深入研究揭示了它们之间的相关性，包括众所周知的普遍恒星质量-金属丰度关系。 然而，由于矮星系存在于各种不同的环境中，通过将这些天体的研究扩展到各种位置，可以深入了解星系形成和演化。 我们展示了对56个矮星系的MUSE光谱数据，作为对MATLAS调查在本地体积以外低至中等密度环境中的后续研究。 这些矮星系的恒星质量范围为$M_{*}/M_{\odot}$ = 10$^{6.1}$-10$^{9.4}$，距离范围为D = 14-148 Mpc，其中大部分（75%）位于MATLAS调查的目标范围内（10-45 Mpc）。 因此，我们报告了在此处呈现的子样本中，MATLAS调查中矮星系半自动识别的成功率为75%（矮椭圆星系为79%）。 使用pPXF全谱拟合，我们确定了它们的视线速度，并能够将大多数与它们的巨大多星系宿主匹配。 对其光谱的仔细检查显示，约30%显示出清晰的发射线，因此有恒星形成活动。 我们估计了它们的恒星种群特性（年龄和金属量），并将我们的结果与其他研究本地体积和星系团中矮星系的工作进行了比较。 我们发现，本文中呈现的矮星系在相同恒星质量下表现出相对于恒星质量-金属丰度关系向较低金属量的系统偏移。 在本工作所探测的恒星质量范围内，其他工作中也存在类似的偏差，可能是由于使用了不同的金属量推导方法。 显示英文摘要

摘要： Dwarf galaxies have been extensively studied in the Local Group, in nearby groups, and selected clusters, giving us a robust picture of their global stellar and dynamical properties in particular locations in the Universe. Intense study of these properties has revealed correlations between them, including the well known universal stellar mass-metallicity relation. However, since dwarfs play a role in a vast range of different environments, much can be learned about galaxy formation and evolution through extending the study of these objects to various locations. We present MUSE spectroscopy of a sample of 56 dwarf galaxies as a follow-up to the MATLAS survey in low-to-moderate density environments beyond the Local Volume. The dwarfs have stellar masses in the range of $M_{*}/M_{\odot}$ = 10$^{6.1}$-10$^{9.4}$ and show a distance range of D = 14-148 Mpc, the majority (75%) of which are located in the range targeted by the MATLAS survey (10-45 Mpc). We thus report a 75% (79% for dwarf ellipticals) success rate for the semi-automatic identification of dwarf galaxies in the MATLAS survey on the here presented subsample. Using pPXF full spectrum fitting, we determine their line-of-sight velocity and can match the majority of them with their massive host galaxy. Close inspection of their spectra reveals that ~30% show clear emission lines and thus star formation activity. We estimate their stellar population properties (age and metallicity) and compare our results with other works investigating Local Volume and cluster dwarf galaxies. We find that the dwarf galaxies presented in this work show a systematic offset from the stellar mass-metallicity relation towards lower metallicities at the same stellar mass. A similar deviation is present in other works in the stellar mass range probed in this work and might be attributed to the use of different methodologies for deriving the metallicity.