The environmental dependence of the relations between stellar mass, structure, star formation and nuclear activity in galaxies
The environmental dependence of the relations between stellar mass, structure, star formation and nuclear activity in galaxies
复制标题
DOI：
10.1111/j.1365-2966.2004.08117.x
复制
发表时间：
2004-02
影响因子：
4.8
通讯作者：
G. Kauffmann;S. White;T. Heckman;B. Ménard;J. Brinchmann;S. Charlot;C. Tremonti;J. Brinkmann
中科院分区：
文献类型：
--
作者：
G. Kauffmann;S. White;T. Heckman;B. Ménard;J. Brinchmann;S. Charlot;C. Tremonti;J. Brinkmann
我们使用从斯隆数字巡天中抽取的一个完整的星系样本，来研究结构、恒星形成和核活动如何依赖于局域密度以及恒星质量。局域密度是通过计算在投影半径为2百万秒差距、深度为±500千米/秒的圆柱体内，高于一个固定绝对星等极限的星系数量来估算的。在低密度区域和高密度区域之间，星系的恒星质量分布朝着更高质量方向移动了近两倍。在恒星质量固定的情况下，恒星形成和核活动都强烈依赖于局域密度，而诸如大小和集中度等结构参数几乎与之无关。只有对于低质量星系（M* < 3×10¹⁰M⊙），恒星形成率才会随着局域密度的增加而急剧下降。我们发现，在过去10亿年里，恒星形成率的下降幅度与局域密度的增加幅度大致相同，这意味着恒星形成率的下降时间尺度约为10亿年。由于对于质量大于3×10¹⁰M⊙的星系，结构不依赖于环境，所以这些系统中近期恒星形成历史、尘埃和核活动的趋势不可能是由改变结构的过程（例如合并或骚扰）所驱动的。恒星形成历史 - 密度相关性对于局域密度的小尺度估算最为强烈。我们没有发现任何证据表明，在距离一个星系超过1百万秒差距的地方，恒星形成历史还会依赖于环境。最后，我们强调了星系群的变化作为密度的函数和作为红移的函数之间惊人的相似性。我们使用从N体模拟中得到的模拟星表来解释这是如何被理解的。
We use a complete sample of galaxies drawn from the Sloan Digital Sky Survey to study how structure, star formation and nuclear activity depend on local density and on stellar mass. Local density is estimated by counting galaxies above a fixed absolute magnitude limit within cylinders 2 Mpc in projected radius and ±500 km s -1 in depth. The stellar mass distribution of galaxies shifts by almost a factor of two towards higher masses between low-and high-density regions. At fixed stellar mass both star formation and nuclear activity depend strongly on local density, while structural parameters such as size and concentration are almost independent of it. Only for low-mass galaxies (M * 1-Gyr) time-scales. Since structure does not depend on environment for galaxies with masses greater than 3 x 10 10 M ○. , the trends in recent SFH, dust and nuclear activity in these systems cannot be driven by processes that alter structure, for example mergers or harassment. The SFH-density correlation is strongest for small-scale estimates of local density. We see no evidence that star formation history depends on environment more than 1 Mpc from a galaxy. Finally, we highlight a striking similarity between the changes in the galaxy population as a function of density and as a function of redshift. We use mock catalogues derived from N-body simulations to explain how this may be understood.