A LINK BETWEEN STAR FORMATION QUENCHING AND INNER STELLAR MASS DENSITY IN SLOAN DIGITAL SKY SURVEY CENTRAL GALAXIES
A LINK BETWEEN STAR FORMATION QUENCHING AND INNER STELLAR MASS DENSITY IN SLOAN DIGITAL SKY SURVEY CENTRAL GALAXIES
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DOI：
10.1088/0004-637x/776/1/63
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发表时间：
2013-08
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影响因子：
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通讯作者：
Jerome J. Fang;S. Faber;D. Koo;A. Dekel
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作者：
Jerome J. Fang;S. Faber;D. Koo;A. Dekel
利用Sloan数字巡天中心星系样本研究了星系结构与星星形成猝灭之间的相关性，星系质量为9.75 < log M*/M < 11.25，红移z < 0.075。星系演化探测器的紫外线数据被用来将样本清晰地划分为恒星形成星系和淬灭星系，并识别过渡星系（绿色谷）。尽管蓝色和红色星系在视觉上有着明显的差异，但它们的平均径向恒星质量密度分布在固定质量下非常相似（特别是在外部区域）。半径为1 kpc的内部恒星质量表面密度，101，被用来量化星系演化过程中凸起的增长。当星系被划分成狭窄的质量箱时，它们在色平面上以固定质量的分布形成了合理的演化轨迹。当星系穿过蓝色星云时，δ 1似乎会增长，一旦它超过一个阈值，星系就会在固定的δ 1处熄灭。淬灭的阈值随恒星质量的增加而增加。然而，一些恒星形成星系的存在高于阈值101意味着一个致密的隆起是必要的，但不足以完全淬灭星系。这与两步淬火过程是一致的，在这个过程中，星系内的气体通过膨胀驱动的过程（如星暴、活动星系核反馈或形态淬火）被去除或稳定，以防止星星的形成，而外部气体吸积则被单独的晕驱动过程（如晕气体冲击加热）抑制。因此，淬灭取决于星系内部结构与周围暗物质晕之间的相互作用，两者之间缺乏完美的同步性可能会产生所观察到的颜色散射。
We study the correlation between galaxy structure and the quenching of star formation using a sample of Sloan Digital Sky Survey central galaxies with stellar masses 9.75 < log M*/M☉ < 11.25 and redshifts z < 0.075. Galaxy Evolution Explorer UV data are used to cleanly divide the sample into star-forming and quenched galaxies and to identify galaxies in transition (the green valley). Despite a stark difference in visual appearance between blue and red galaxies, their average radial stellar mass density profiles are remarkably similar (especially in the outer regions) at fixed mass. The inner stellar mass surface density within a radius of 1 kpc, Σ1, is used to quantify the growth of the bulge as galaxies evolve. When galaxies are divided into narrow mass bins, their distribution in the color-Σ1 plane at fixed mass forms plausible evolutionary tracks. Σ1 seems to grow as galaxies evolve through the blue cloud, and once it crosses a threshold value, galaxies are seen to quench at fixed Σ1. The Σ1 threshold for quenching grows with stellar mass, . However, the existence of some star-forming galaxies above the threshold Σ1 implies that a dense bulge is necessary but not sufficient to quench a galaxy fully. This would be consistent with a two-step quenching process in which gas within a galaxy is removed or stabilized against star formation by bulge-driven processes (such as a starburst, active galactic nucleus feedback, or morphological quenching), whereas external gas accretion is suppressed by separate halo-driven processes (such as halo gas shock heating). Quenching thus depends on an interplay between the inner structure of a galaxy and its surrounding dark matter halo, and lack of perfect synchrony between the two could produce the observed scatter in color versus Σ1.