The significant effects of stellar mass estimation on galaxy pair fractions.
The significant effects of stellar mass estimation on galaxy pair fractions.
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恒星质量估计对星系对分数的显着影响。
DOI：
10.1093/mnras/staa2966
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发表时间：
2020
期刊：
影响因子：
--
通讯作者：
C. Conselice
中科院分区：
文献类型：
--
作者：
P. Grylls;F. Shankar;C. Conselice
对星系对的数量和演化的测量存在差异。配对分数似乎是敏感的标准来选择配对分数和方法来分析调查数据。本文利用STEEL统计经验模型探讨了恒星质量估算与星系偶分数之间的联系。以前的结果发现，对分数是敏感的选择时，选择什么资格作为一对，例如光度或恒星质量的选择。我们发现，不同的估计恒星质量，如光度选择质光比或IMF的恒星质量函数的影响也显着影响派生的星系对分数。通过利用星系晕的联系，我们调查这些系统的对分数的影响。我们约束星系晕连接使用恒星质量晕质量关系的两个观测到的恒星质量函数，和插图TNG恒星质量函数。此外，我们还创建了一套玩具模型，其中恒星质量晕质量关系是手动改变的。对于每一个恒星质量晕质量关系的对分数，及其演变，产生。我们发现，高质量星系的数量密度的增强导致恒星质量晕质量关系的陡峭化，导致对分数的减少。我们认为，这是一个相当大的偏差，必须占比较对分数时的原因。
There exist discrepancies in measurements of the number and evolution of galaxy pairs. The pair fraction appears to be sensitive to both the criteria used to select pair fraction and the methods used to analyze survey data. This paper explores the connection between stellar mass estimation and the pair fraction of galaxies making use of STEEL, the Statistical sEmi-Emprical modeL. Previous results have found the pair fraction is sensitive to choices made when selecting what qualifies as a pair, for example luminosity or stellar mass selections. We find that different estimations of stellar mass such as photometric choice mass-to-light ratio or IMF that effect the stellar mass function also significantly affect the derived galaxy pair fraction. By making use of the galaxy halo connection we investigate these systematic affects on the pair fraction. We constrain the galaxy halo connection using the stellar-mass-halo-mass relationship for two observed stellar mass functions, and the Illustris TNG stellar mass function. Furthermore, we also create a suite of toy models where the stellar-mass-halo-mass relationship is manually changed. For each stellar-mass-halo-mass relation the pair fraction, and its evolution, are generated. We find that enhancements to the number density of high mass galaxies cause steepening of the stellar-mass-halo mass relation, resulting in a reduction of the pair fraction. We argue this is a considerable cause of bias that must be accounted for when comparing pair fractions.