The dependence of star formation history and internal structure on stellar mass for 105 low‐redshift galaxies
The dependence of star formation history and internal structure on stellar mass for 105 low‐redshift galaxies
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DOI：
10.1046/j.1365-8711.2003.06292.x
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发表时间：
2002-05
影响因子：
4.8
通讯作者：
G. Kauffmann;T. Heckman;S. White;S. Charlot;C. Tremonti;E. Peng;M. Seibert;J. Brinkmann;R. Nich
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文献类型：
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作者：
G. Kauffmann;T. Heckman;S. White;S. Charlot;C. Tremonti;E. Peng;M. Seibert;J. Brinkmann;R. Nich
本文以斯隆数字巡天的122808个星系为样本，研究了恒星质量、星星形成历史、大小和内部结构之间的关系。我们发现，低红移星系分为两个不同的家庭在3 × 10 - 1 0 M O的恒星质量。低质量星系有年轻的恒星群体，低表面质量密度和典型的圆盘低浓度。它们的星星形成历史与表面质量密度的相关性比与恒星质量的相关性更强。在我们的样本中，质量最低的星系中有很大一部分经历了最近的星爆。在恒星质量一定的情况下，低质量星系的大小服从对数正态分布，色散σ（In R50）<$0.5，这与它们在引力主导的暗物质晕中通过冷却和凝聚而几乎没有角动量损失的观点非常一致。它们的平均恒星表面质量密度与恒星质量的比例为μ * M * 0.54，这表明盘状星系的恒星质量与其晕质量的三次方成正比。所有这些都表明，在低质量星系中，重子转化为恒星的效率与晕质量成比例地增加，这可能是超新星反馈过程的结果。当恒星质量超过3 × 10 10 M O时，有一个快速增加的部分星系的老恒星人口，高表面质量密度和高浓度的典型的隆起。在这种状态下，尺寸分布保持对数正态分布，但其色散随着质量的增加而迅速减小，并且恒星质量表面密度的中值近似为常数。这表明，在最高质量的晕中，星星的形成效率降低，而在大质量星系聚集后，几乎没有星星形成。
We study the relations between stellar mass, star formation history, size and internal structure for a complete sample of 122 808 galaxies drawn from the Sloan Digital Sky Survey. We show that low-redshift galaxies divide into two distinct families at a stellar mass of 3 x 10 1 0 M O .. Lower-mass galaxies have young stellar populations, low surface mass densities and the low concentrations typical of discs. Their star formation histories are more strongly correlated with surface mass density than with stellar mass. A significant fraction of the lowest-mass galaxies in our sample have experienced recent starbursts. At given stellar mass, the sizes of low-mass galaxies are lognormally distributed with dispersion σ(In R 5 0 ) ∼0.5, in excellent agreement with the idea that they form with little angular momentum loss through cooling and condensation in a gravitationally dominant dark matter halo. Their median stellar surface mass density scales with stellar mass as μ * M * 0.54, suggesting that the stellar mass of a disc galaxy is proportional to the three halves power of its halo mass. All of this suggests that the efficiency of the conversion of baryons into stars in low-mass galaxies increases in proportion to halo mass, perhaps as a result of supernova feedback processes. At stellar masses above 3 x 10 1 0 M O ., there is a rapidly increasing fraction of galaxies with old stellar populations, high surface mass densities and the high concentrations typical of bulges. In this regime, the size distribution remains lognormal, but its dispersion decreases rapidly with increasing mass and the median stellar mass surface density is approximately constant. This suggests that the star formation efficiency decreases in the highest-mass haloes, and that little star formation occurs in massive galaxies after they have assembled.