论文标题
带有TNG50的银河系和M31状星系的卫星：猝灭的分数，气体含量和星形形成历史
Satellites of Milky Way- and M31-like galaxies with TNG50: quenched fractions, gas content, and star formation histories
论文作者
论文摘要
我们分析了约有1200个卫星星系的淬火分数，气体含量和恒星形成历史，这些星系具有$ M_* \ GEQ 5 \ GEQ 5 \ times 10^6〜 {\ rm M} _ \ odot $左右，约198个银河系 - （mw）和仙女（M31）和TNG50中的oft-like（m31）托管。对于较小的质量，卫星淬灭的部分较小，与宿主星系较小的距离较小，并且与MW样宿主相比，M31的较大较大。随着卫星越过宿主的病毒半径，他们的气体含量下降了：大多数卫星在300 kpc以内的大多数卫星都缺乏$ z = 0 $的可检测到的气体储层，除非它们像麦哲伦云和M32一样大。然而，他们的出色组装表现出很大程度的多样性。平均而言，累积恒星形成历史更扩展，以更明亮，更大的卫星，并以更高的插入式卫星，以及那些在较少的宿主中的卫星。基于这些关系，我们甚至可以推断观察到的M31矮人的插入周期：例如0-4 Gyr of Magellanic Clouds和Leo I，分别为M32和IC 10的4-8和0-2 Gyr。 RAM压力剥离（与潮汐剥离结合使用）剥夺了TNG50卫星的气体储层，并最终消除了他们的星形地层，即使目前的卫星中只有几％在198 TNG50 MW/M31类似的宿主附近出现时出现为水母。自当前淬火TNG50卫星的淬火以来的典型时间为$ 6.9^{+2.5} _ { - 3.3}〜{\ rm gyr} $ ogo。 TNG50结果与观察到的MW和M31卫星的淬火分数和恒星组装一致，但是，使用$ M_* \ sim 10^{8-9}〜{\ rm M} _ \ rm M} _ \ odot $比TNG50和其他较低的淬火分数和其他观察。
We analyse the quenched fractions, gas content, and star formation histories of ~1200 satellite galaxies with $M_* \geq 5 \times 10^6~{\rm M}_\odot$ around 198 Milky Way- (MW) and Andromeda-like (M31) hosts in TNG50, the highest-resolution simulation of IllustrisTNG. Satellite quenched fractions are larger for smaller masses, for smaller distances to their host galaxy, and in the more massive M31-like compared to MW-like hosts. As satellites cross their host's virial radius, their gas content drops: most satellites within 300 kpc lack detectable gas reservoirs at $z=0$, unless they are massive like the Magellanic Clouds and M32. Nevertheless, their stellar assembly exhibits a large degree of diversity. On average, the cumulative star formation histories are more extended for brighter, more massive satellites with a later infall, and for those in less massive hosts. Based on these relationships, we can even infer infall periods for observedMWand M31 dwarfs: e.g. 0-4 Gyr ago for the Magellanic Clouds and Leo I, 4-8 and 0-2 Gyr ago for M32 and IC 10, respectively. Ram pressure stripping (in combination with tidal stripping) deprives TNG50 satellites of their gas reservoirs and ultimately quenches their star formation, even though only a few per cent of the present-day satellites around the 198 TNG50 MW/M31-like hosts appear as jellyfish. The typical time since quenching for currently quenched TNG50 satellites is $6.9^{+2.5}_{-3.3}~{\rm Gyr}$ ago. The TNG50 results are consistent with the quenched fractions and stellar assembly of observed MW and M31 satellites, however, satellites of the SAGA survey with $M_* \sim 10^{8-9}~{\rm M}_\odot$ exhibit lower quenched fractions than TNG50 and other, observed analogues.
