MORPHOLOGICAL QUENCHING OF STAR FORMATION: MAKING EARLY-TYPE GALAXIES RED
MORPHOLOGICAL QUENCHING OF STAR FORMATION: MAKING EARLY-TYPE GALAXIES RED
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DOI：
10.1088/0004-637x/707/1/250
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发表时间：
2009-05
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影响因子：
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通讯作者：
M. Martig;F. Bournaud;R. Teyssier;A. Dekel
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文献类型：
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作者：
M. Martig;F. Bournaud;R. Teyssier;A. Dekel
指出了早型星系中星星形成猝灭的一种自然机制。它自动将星系的颜色与其形态联系起来，不需要消耗气体、去除或终止气体供应。由于星星的形成发生在引力不稳定的气体盘中，当气体盘变得稳定而不会碎裂成束缚的团块时，恒星就会被淬灭。这可能是由于恒星球体的生长，例如合并。我们提出的概念，形态淬火（MQ）使用标准磁盘不稳定性分析，并证明其自然发生在宇宙学模拟使用一个有效的放大技术。我们表明，从恒星盘的过渡到球体可以足以稳定的气体盘，淬火星星的形成，并把ETG红色和死亡，而气体吸积继续。在没有恒星形成团块的情况下，盘内的剪切扰动可以激起盘稳定所必需的湍流。虽然其他淬灭机制，如气体剥离，活动星系核反馈，维里冲击加热和引力加热仅限于大质量晕，MQ可以解释红色ETG的出现也在质量小于1012 M的晕中。在今天的一些红色椭圆星系中观察到的致密气体盘可能是这种机制的遗迹，而具有淬灭气体盘的红色星系在高红移时可能更常见。
We point out a natural mechanism for quenching of star formation in early-type galaxies (ETGs). It automatically links the color of a galaxy with its morphology and does not require gas consumption, removal or termination of gas supply. Given that star formation takes place in gravitationally unstable gas disks, it can be quenched when a disk becomes stable against fragmentation to bound clumps. This can result from the growth of a stellar spheroid, for instance by mergers. We present the concept of morphological quenching (MQ) using standard disk instability analysis, and demonstrate its natural occurrence in a cosmological simulation using an efficient zoom-in technique. We show that the transition from a stellar disk to a spheroid can be sufficient to stabilize the gas disk, quench star formation, and turn an ETG red and dead while gas accretion continues. The turbulence necessary for disk stability can be stirred up by sheared perturbations within the disk in the absence of bound star-forming clumps. While other quenching mechanisms, such as gas stripping, active galactic nucleus feedback, virial shock heating, and gravitational heating are limited to massive halos, MQ can explain the appearance of red ETGs also in halos less massive than ∼1012 M ☉. The dense gas disks observed in some of today's red ellipticals may be the relics of this mechanism, whereas red galaxies with quenched gas disks could be more frequent at high redshift.