Galaxy Number Counts in the Hubble Deep Field as a Strong Constraint on a Hierarchical Galaxy Formation Model
Galaxy Number Counts in the Hubble Deep Field as a Strong Constraint on a Hierarchical Galaxy Formation Model
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哈勃深场中的星系数量是对分层星系形成模型的强有力约束
DOI：
10.1086/322260
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发表时间：
2001
期刊：
影响因子：
--
通讯作者：
Y. Yoshii
中科院分区：
文献类型：
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作者：
M. Nagashima;T. Totani;N. Gouda;Y. Yoshii
星系的数量计数重新分析使用半解析模型（SAM）的星系形成的层次聚类方案的基础上。我们已经确定了SAM中再现附近星系观测的天体物理参数，并利用它们预测了三种宇宙学模型中暗星系的计数和红移：（1）标准冷暗物质（CDM）宇宙，（2）具有非零宇宙学常数的低密度平坦宇宙，和（3）具有零宇宙学常数的低密度开放宇宙。我们的SAM分析的新奇在于包含了选择效应所产生的宇宙学调光的表面亮度的高红移星系，也从可见光的吸收内部尘埃和星系际的H I云。相反，以前的SAM分析，不考虑这种选择效应，我们发现从观察到的计数和红移的微弱星系在哈勃深场（HDF），标准的CDM宇宙是不可取的，和低密度的宇宙无论是有或没有宇宙学常数是有利的，最近的其他研究表明。此外，我们还发现，一个简单的星星形成时间尺度（SF）的公式（SF与银盘形成的动力学时间尺度成正比）不能再现HDF星系观测到的数-红移关系，SF时间尺度应该与红移几乎无关，这与其他SAM分析类星体形成和阻尼Lyα系统演化的结果一致。
Number counts of galaxies are reanalyzed using a semianalytic model (SAM) of galaxy formation based on the hierarchical clustering scenario. We have determined the astrophysical parameters in the SAM that reproduce observations of nearby galaxies and used them to predict the number counts and redshifts of faint galaxies for three cosmological models: (1) the standard cold dark matter (CDM) universe, (2) a low-density flat universe with nonzero cosmological constant, and (3) a low-density open universe with zero cosmological constant. The novelty of our SAM analysis is the inclusion of selection effects arising from the cosmological dimming of the surface brightness of high-redshift galaxies and also from the absorption of visible light by internal dust and intergalactic H I clouds. Contrary to previous SAM analyses that do not take into account such selection effects, we find from comparison with observed counts and redshifts of faint galaxies in the Hubble Deep Field (HDF) that the standard CDM universe is not preferred, and a low-density universe either with or without a cosmological constant is favorable, as suggested by other recent studies. Moreover, we find that a simple prescription for the timescale of star formation (SF), being proportional to the dynamical timescale of the formation of the galactic disk, is unable to reproduce the observed number-redshift relation for HDF galaxies, and that the SF timescale should be nearly independent of redshift, as suggested by other SAM analyses for the formation of quasars and the evolution of damped Lyα systems.
直接合成磷脂酰葡萄糖苷的新方法
DOI：
--
发表时间：
2022
期刊：
影响因子：
--
作者：
Kano Koki;Nozomi Ishii;Peter Greimel;Ichiro Matsuo
通讯作者：
Ichiro Matsuo