Interpreting the Relationship between Galaxy Luminosity, Color, and Environment
Interpreting the Relationship between Galaxy Luminosity, Color, and Environment
复制标题
DOI：
10.1086/431658
复制
发表时间：
2004-06
期刊：
影响因子：
--
通讯作者：
A. Berlind;M. Blanton;D. Hogg;D. Weinberg;R. Dav'e;D. Eisenstein;N. Katz
中科院分区：
文献类型：
--
作者：
A. Berlind;M. Blanton;D. Hogg;D. Weinberg;R. Dav'e;D. Eisenstein;N. Katz
我们在星系形成的宇宙学模拟中研究了星系亮度、颜色和环境之间的关系。使用一个简单的处方来分配模拟星系的颜色和亮度，我们将预测的关系与SDSS星系的观测结果进行了比较，发现该模型成功地预测了数据中看到的大多数定性特征，但也显示了一些有趣的差异。具体地说，模拟预测了明亮红色星系周围的局部密度是光度的一个强递增函数，但在固定光度下不太依赖于颜色。此外，我们表明这些趋势是由于暗物质晕中的中心星系，其重子质量与晕质量密切相关。模拟还预测，蓝色星系周围的局部密度是一个强烈的颜色递增函数，但不太依赖于固定颜色下的亮度。我们表明这些趋势是由于晕中的卫星星系，其恒星年龄与晕质量相关。最后，模拟不能预测在低光度红星系周围观测到的环境对光度的依赖性。然而，我们表明，这很可能是由于模拟的有限分辨率。一项更高分辨率、更小体积模拟的研究表明，这种依赖性是由以下事实造成的：所有低光度的红色星系都是大质量晕中的卫星星系，而中等光度的红色星系是大质量晕中的卫星星系和小质量晕中的中心星系的混合物。
We study the relationship between galaxy luminosity, color, and environment in a cosmological simulation of galaxy formation. Using a simple prescription to assign colors and luminosities to simulated galaxies, we compare the predicted relationship with that observed for SDSS galaxies and find that the model successfully predicts most of the qualitative features seen in the data, but also shows some interesting differences. Specifically, the simulation predicts that the local density around bright red galaxies is a strong increasing function of luminosity, but does not depend much on color at fixed luminosity. Moreover, we show that these trends are due to central galaxies in dark matter halos whose baryonic masses correlate strongly with halo mass. The simulation also predicts that the local density around blue galaxies is a strong increasing function of color, but does not depend much on luminosity at fixed color. We show that these trends are due to satellite galaxies in halos whose stellar ages correlate with halo mass. Finally, the simulation fails to predict the luminosity dependence of environments observed around low-luminosity red galaxies. However, we show that this is most likely due to the simulation's limited resolution. A study of a higher resolution, smaller volume simulation suggests that this dependence is caused by the fact that all low-luminosity red galaxies are satellites in massive halos, whereas intermediate-luminosity red galaxies are a mixture of satellites in massive halos, and central galaxies in less massive halos.