How does galaxy environment matter? The relationship between galaxy environments, colour and stellar mass at 0.4 < z < 1 in the Palomar/DEEP2 survey
How does galaxy environment matter? The relationship between galaxy environments, colour and stellar mass at 0.4 < z < 1 in the Palomar/DEEP2 survey
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DOI：
10.1111/j.1365-2966.2010.17727.x
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发表时间：
2010-09
影响因子：
4.8
通讯作者：
R. Grutzbauch;C. Conselice;J. Varela;K. Bundy;M. Cooper;R. Skibba;C. Willmer
中科院分区：
文献类型：
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作者：
R. Grutzbauch;C. Conselice;J. Varela;K. Bundy;M. Cooper;R. Skibba;C. Willmer
基于POWIR近红外成像和DEEP 2光谱红移巡天的数据，我们提出了一项研究，描述了红移范围为0.4 < z < 1的星系的环境，直到恒星质量为log M*= 10.25 M。星系环境是以最近邻星系的密度、固定孔径密度以及半径为1 h−1 Mpc的邻近星系的运动学和动力学参数来衡量的。我们解开星系恒星质量，星系颜色和星系环境之间的相关性，不仅使用星系数密度，而且还使用其他环境特征，如速度色散，平均谐波半径和穿越时间。我们发现，星系的颜色和蓝色星系的比例在0.4 < z < 1时非常强烈地依赖于恒星质量，而在较低的红移（0.4 < z < 0.7）时，对局域数密度的依赖性很弱。这种环境影响在中等质量星系的颜色中最为明显（10.5 < log M* < 11），而低质量和高质量星系的颜色在红移和环境中基本保持不变。在恒星质量固定的情况下，颜色-密度关系几乎消失，而颜色-恒星质量关系在所有局域密度下都存在。我们发现在中等红移的恒星质量和环境之间的弱相关性，这有助于整体的颜色密度关系。此外，我们没有发现星系的颜色和维里质量，即母暗物质晕质量之间的显着相关性。因此，星系的恒星质量似乎是决定星系内在性质的关键参数，如正在进行的星星形成和颜色。
We present a study characterizing the environments of galaxies in the redshift range of 0.4 < z < 1 based on data from the POWIR near-infrared imaging and DEEP2 spectroscopic redshift surveys, down to a stellar mass of log M*= 10.25 M⊙. Galaxy environments are measured in terms of nearest-neighbour densities as well as fixed aperture densities and kinematical and dynamical parameters of neighbour galaxies within a radius of 1 h−1 Mpc. We disentangle the correlations between galaxy stellar mass, galaxy colour and galaxy environment, using not only galaxy number densities, but also other environmental characteristics such as velocity dispersion, mean harmonic radius and crossing time. We find that galaxy colour and the fraction of blue galaxies depends very strongly on stellar mass at 0.4 < z < 1, while a weak additional dependence on local number densities is in place at lower redshifts (0.4 < z < 0.7). This environmental influence is most visible in the colours of intermediate-mass galaxies (10.5 < log M* < 11), whereas colours of lower- and higher-mass galaxies remain largely unchanged with redshift and environment. At a fixed stellar mass, the colour–density relation almost disappears, while the colour–stellar mass relation is present at all local densities. We find a weak correlation between stellar mass and environment at intermediate redshifts, which contributes to the overall colour–density relation. We furthermore do not find a significant correlation between galaxy colour and virial mass, i.e. parent dark matter halo mass. Galaxy stellar mass thus appears to be the crucial defining parameter for intrinsic galaxy properties such as ongoing star formation and colour.