论文标题
精灵三:银河系宿主的环境淬火
ELVES III: Environmental Quenching by Milky Way-Mass Hosts
论文作者
论文摘要
孤立的矮星系通常表现出强大的恒星形成,但卫星矮星系通常没有年轻的恒星,即使是在银河系中也没有恒星。因此,矮星系为停止恒星形成的环境过程提供了重要的实验室。我们探讨了左右卫星星系的样本,探索了局部体积卫星(精灵)调查的静态星系(淬灭分数)的平衡。我们提出淬灭的分数是卫星恒星质量,投射半径和宿主光环质量的函数,得出的结论是,总体而言,淬灭的分数与银河系相似,在卫星M* 〜10^8 m_sun处下降到50%以下。我们可能会看到暗示在较大半径下淬火效率较低。通过与半分析建模代码SATGEN进行比较,我们还能够推断出平均淬火时间随宿主卤素垃圾箱中卫星质量的函数。卫星恒星质量的淬火时间逐渐增加,而不是从迅速变为缓慢的淬火变化,这是银河系推断的。我们通常还比最近的流体动力学模拟还可以推断出更长的平均淬火时间。我们的结果与模型一致,该模型表明,通过横压剥离,可能是可能的大量淬火时间,这取决于环境培养基的块,卫星的轨道以及早期的预处理程度。
Isolated dwarf galaxies usually exhibit robust star formation but satellite dwarf galaxies are often devoid of young stars, even in Milky Way-mass groups. Dwarf galaxies thus offer an important laboratory of the environmental processes that cease star formation. We explore the balance of quiescent and star-forming galaxies (quenched fractions) for a sample of ~400 satellite galaxies around 30 Local Volume hosts from the Exploration of Local VolumE Satellites (ELVES) Survey. We present quenched fractions as a function of satellite stellar mass, projected radius, and host halo mass, to conclude that overall, the quenched fractions are similar to the Milky Way, dropping below 50% at satellite M* ~ 10^8 M_sun. We may see hints that quenching is less efficient at larger radius. Through comparison with the semi-analytic modeling code satgen, we are also able to infer average quenching times as a function of satellite mass in host halo-mass bins. There is a gradual increase in quenching time with satellite stellar mass rather than the abrupt change from rapid to slow quenching that has been inferred for the Milky Way. We also generally infer longer average quenching times than recent hydrodynamical simulations. Our results are consistent with models that suggest a wide range of quenching times are possible via ram-pressure stripping, depending on the clumpiness of the circumgalactic medium, the orbits of the satellites, and the degree of earlier preprocessing.