The New Numerical Galaxy Catalog ($\nu^2$GC): An Updated Semi-analytic Model of Galaxy and AGN with Large Cosmological N-body Simulation
The New Numerical Galaxy Catalog ($\nu^2$GC): An Updated Semi-analytic Model of Galaxy and AGN with Large Cosmological N-body Simulation
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DOI：
10.1093/pasj/psw005
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发表时间：
2015-08
期刊：
影响因子：
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通讯作者：
R. Makiya;M. Enoki;T. Ishiyama;Masakazu A. R. Kobayashi;M. Nagashima;T. Okamoto;K. Okoshi;T. Oogi-T.-O
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文献类型：
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作者：
R. Makiya;M. Enoki;T. Ishiyama;Masakazu A. R. Kobayashi;M. Nagashima;T. Okamoto;K. Okoshi;T. Oogi-T.-O
我们提出了一个新的宇宙学星系形成模型，$\nu^2$GC，作为我们以前的模型$\nu$GC的更新版本。我们采用了所谓的“半解析”方法，其中暗物质晕的形成历史由${\itN}$体模拟计算，而重子物理如气体冷却、星星形成和超新星反馈等则由唯象方程简单地模拟。模型的主要更新如下：（1）在最先进的${\itN}$体模拟中构造了暗物质晕的合并树，（2）介绍了超大质量黑洞的形成和演化过程以及活动星系核（AGN）活动对气体冷却的抑制，（3）考虑了宇宙紫外背景对星系际气体的加热，（4）利用马尔可夫链蒙特卡罗方法对与天体物理过程相关的自由参数进行了调整。我们对暗物质晕的${\it N}$体模拟具有前所未有的盒子大小和质量分辨率（最大的模拟在1.12 Gpc/h的盒子中包含5500亿个粒子），从而能够研究更小和更稀有的物体。对模型进行了调整，使之能拟合本星系的光度函数和中性氢的质量函数。该模型较好地再现了Tully-Fisher关系、旋涡星系的大小-星等关系以及球核质量与黑洞质量的标度关系等局部观测结果。此外，该模型还很好地再现了宇宙星星的形成历史和静止坐标系K带光度函数的红移演化。模拟星系和活动星系核的数值目录在网上公开。
We present a new cosmological galaxy formation model, $\nu^2$GC, as an updated version of our previous model $\nu$GC. We adopt the so-called "semi-analytic" approach, in which the formation history of dark matter halos is computed by ${\it N}$-body simulations, while the baryon physics such as gas cooling, star formation and supernova feedback are simply modeled by phenomenological equations. Major updates of the model are as follows: (1) the merger trees of dark matter halos are constructed in state-of-the-art ${\it N}$-body simulations, (2) we introduce the formation and evolution process of supermassive black holes and the suppression of gas cooling due to active galactic nucleus (AGN) activity, (3) we include heating of the intergalactic gas by the cosmic UV background, and (4) we tune some free parameters related to the astrophysical processes using a Markov chain Monte Carlo method. Our ${\it N}$-body simulations of dark matter halos have unprecedented box size and mass resolution (the largest simulation contains 550 billion particles in a 1.12 Gpc/h box), enabling the study of much smaller and rarer objects. The model was tuned to fit the luminosity functions of local galaxies and mass function of neutral hydrogen. Local observations, such as the Tully-Fisher relation, size-magnitude relation of spiral galaxies and scaling relation between the bulge mass and black hole mass were well reproduced by the model. Moreover, the model also well reproduced the cosmic star formation history and the redshift evolution of rest-frame ${\it K}$-band luminosity functions. The numerical catalog of the simulated galaxies and AGNs is publicly available on the web.