ELVES. III. Environmental Quenching by Milky Way–mass Hosts
ELVES. III. Environmental Quenching by Milky Way–mass Hosts
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DOI：
10.3847/1538-4357/acc58c
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发表时间：
2022-10
期刊：
影响因子：
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通讯作者：
J. Greene;S. Danieli;S. Carlsten;R. Beaton;F. Jiang;Jiaxuan Li
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作者：
J. Greene;S. Danieli;S. Carlsten;R. Beaton;F. Jiang;Jiaxuan Li
孤立的矮星系通常表现出强劲的恒星形成，但卫星矮星系往往缺乏年轻的恒星，即使在银河系质量群中也是如此。因此，矮星系为停止恒星形成的环境过程提供了一个重要的实验室。我们对来自局部体积卫星探索（elf）调查的约30个局部体积宿主的约400个卫星星系样本探索了静止星系和恒星形成星系（淬灭部分）的平衡。我们将淬灭的部分作为卫星恒星质量、投影半径和宿主光晕质量的函数，得出结论，总的来说，淬灭的部分与银河系相似，在卫星M *≈108 M⊙处下降到50%以下。我们可能会看到在较大半径处淬火效率较低的迹象。通过与半解析建模代码SatGen的比较，我们还能够推断出在宿主光晕质量仓中平均淬火时间作为卫星质量的函数。随着卫星恒星质量的增加，猝灭时间逐渐增加，而不是像银河系那样从快速猝灭到缓慢猝灭的突然变化。与最近的流体动力学模拟相比，我们通常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，根据环星系介质的团块性、卫星的轨道和早期预处理的程度，冲压压力剥离可能产生大范围的淬火时间。
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 * ≈ 108 M ⊙. We may see hints that quenching is less efficient at larger radii. Through comparison with the semianalytic 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.