A machine learning approach to measuring the quenched fraction of low-mass satellites beyond the Local Group
A machine learning approach to measuring the quenched fraction of low-mass satellites beyond the Local Group
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DOI：
10.1093/mnras/stab523
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发表时间：
2021-02
影响因子：
4.8
通讯作者：
Devontae C. Baxter;M. Cooper;S. Fillingham
中科院分区：
文献类型：
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作者：
Devontae C. Baxter;M. Cooper;S. Fillingham
观测表明，卫星淬火在宇宙晚期被动的低质量星系的形成中起着重要作用。然而，对低质量卫星的研究受到了对微弱系统的局部环境和星星形成活动进行强有力描述的能力的限制。为了克服现有数据集的局限性，我们利用深测光条纹82的斯隆数字巡天，结合神经网络分类方案，研究抑制星星形成的低质量卫星星系在本地宇宙。使用统计驱动的方法，我们能够超越现有光谱数据集的限制，测量卫星猝灭分数，在群环境中的卫星恒星质量为107 M（Mhalo = 1013−14 h−1 M）。在高卫星恒星质量（1010 M），我们的分析成功地再现了现有的测量淬火馏分的光谱样品的基础上。推到较低的质量，我们发现，被动卫星的比例增加，潜在的信号中的主要淬火机制在M 109 M的变化。类似的本地组以前的研究结果，在低卫星质量的淬火分数的增加可能对应于增加的冲压压力剥离作为淬火机制组的功效。
Observations suggest that satellite quenching plays a major role in the build-up of passive, low-mass galaxies at late cosmic times. Studies of low-mass satellites, however, are limited by the ability to robustly characterize the local environment and star formation activity of faint systems. In an effort to overcome the limitations of existing data sets, we utilize deep photometry in Stripe 82 of the Sloan Digital Sky Survey, in conjunction with a neural network classification scheme, to study the suppression of star formation in low-mass satellite galaxies in the local Universe. Using a statistically driven approach, we are able to push beyond the limits of existing spectroscopic data sets, measuring the satellite quenched fraction down to satellite stellar masses of ∼107 M⊙ in group environments (Mhalo = 1013−14 h−1 M⊙). At high satellite stellar masses (≳1010 M⊙), our analysis successfully reproduces existing measurements of the quenched fraction based on spectroscopic samples. Pushing to lower masses, we find that the fraction of passive satellites increases, potentially signalling a change in the dominant quenching mechanism at M⋆ ∼ 109 M⊙. Similar to the results of previous studies of the Local Group, this increase in the quenched fraction at low satellite masses may correspond to an increase in the efficacy of ram-pressure stripping as a quenching mechanism in groups.