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外文期刊>The Astrophysical journal
>MASS AND ENVIRONMENT AS DRIVERS OF GALAXY EVOLUTION. II. THE QUENCHING OF SATELLITE GALAXIES AS THE ORIGIN OF ENVIRONMENTAL EFFECTS
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MASS AND ENVIRONMENT AS DRIVERS OF GALAXY EVOLUTION. II. THE QUENCHING OF SATELLITE GALAXIES AS THE ORIGIN OF ENVIRONMENTAL EFFECTS
We extend the phenomenological study of the evolving galaxy population of Peng et?al. (2010) to the central/satellite dichotomy in Yang et?al. Sloan Digital Sky Survey (SDSS) groups. We find that satellite galaxies are responsible for all the environmental effects in our earlier work. The fraction of centrals that are red does not depend on their environment but only on their stellar masses, whereas that of the satellites depends on both. We define a relative satellite quenching efficiency εsat, which is the fraction of blue centrals that are quenched upon becoming the satellite of another galaxy. This is shown to be independent of stellar mass, but to depend strongly on local overdensity, δ, ranging between 0.2 and at least 0.8. The red fraction of satellites correlate much better with the local overdensity δ, a measure of location within the group, than with the richness of the group, i.e., dark matter halo mass. This, and the fact that satellite quenching depends on local density and not on either the stellar mass of the galaxy or the dark matter halo mass, gives clues as to the nature of the satellite-quenching process. We furthermore show that the action of mass quenching on satellite galaxies is also independent of the dark matter mass of the parent halo. We then apply the Peng et?al. approach to predict the mass functions of central and satellite galaxies, split into passive and active galaxies, and show that these match very well the observed mass functions from SDSS, further strengthening the validity of this phenomenological approach. We highlight the fact that the observed M* is exactly the same for the star-forming centrals and satellites and the observed M* for the star-forming satellites is independent of halo mass above 1012 M ☉, which emphasizes the universality of the mass-quenching process that we identified in Peng et?al. Post-quenching merging modifies the mass function of the central galaxies but can increase the mass of typical centrals by only about 25%.
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机译：我们扩展了彭等人正在进化的银河系种群的现象学研究。 （2010）到杨等人的中央/卫星二分法。斯隆数字天空调查（SDSS）组。我们发现，在我们早期的工作中，卫星星系对所有环境影响负有责任。红色的中心部分不取决于其环境，而仅取决于其恒星质量，而卫星的部分取决于这两者。我们定义了一个相对的卫星猝灭效率εsat，它是蓝色中心在成为另一个星系的卫星后被猝灭的部分。已显示这与恒星质量无关，但在很大程度上取决于局部过密度δ，范围在0.2到至少0.8之间。卫星的红色部分与局部超密度δ（组内位置的度量）的相关性比与组的丰富度（即暗物质晕圈质量）的相关性更好。这以及卫星猝灭取决于局部密度而不取决于星系的恒星质量或暗物质晕质量的事实，为卫星猝灭过程的性质提供了线索。我们进一步表明，质量猝灭对卫星星系的作用也与母体晕的暗物质质量无关。然后我们应用Peng等人。这种方法可以预测中心星系和卫星星系的质量函数，分为被动星系和主动星系，并且表明它们与从SDSS观测到的质量函数非常匹配，从而进一步增强了这种现象学方法的有效性。我们强调这样一个事实：对于恒星形成的中心和卫星，观测到的M *完全相同，对于恒星形成的卫星，观测到的M *与1012 M above以上的晕质量无关，这强调了质量恒量的普遍性。我们在Peng等人中确定的淬火过程。猝灭后合并会修改中心星系的质量函数，但只会使典型中心的质量增加约25％。
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