Simulating galaxies in the reionization era with FIRE-2: galaxy scaling relations, stellar mass functions, and luminosity functions
Simulating galaxies in the reionization era with FIRE-2: galaxy scaling relations, stellar mass functions, and luminosity functions
复制标题
DOI：
10.1093/mnras/sty1024
复制
发表时间：
2017-06
影响因子：
4.8
通讯作者：
Xiangcheng Ma;P. Hopkins;S. Garrison-Kimmel;C. Faucher-Giguère;E. Quataert;M. Boylan-Kolchin;C. Hayward
中科院分区：
文献类型：
--
作者：
Xiangcheng Ma;P. Hopkins;S. Garrison-Kimmel;C. Faucher-Giguère;E. Quataert;M. Boylan-Kolchin;C. Hayward
我们提出了现实环境反馈项目中 z>5 的一套宇宙学放大模拟，跨越 z=5 时的晕质量范围 M_halo~10^8-10^12 M_sun。我们预测了 z=5-12 的几个波段中的恒星质量-晕质量关系、恒星质量函数和光度函数。中值恒星质量与光晕质量关系在 z=5-12 时演化不强烈。光度函数的微端斜率随着红移的增加而变陡，这是从这些红移处的晕质量函数继承的。在z~6以下，恒星质量函数和紫外（UV）光度函数在M_star~10^4.5 M_sun以下（比M_1500~-12更弱）略微平坦，这是因为低质量晕中的恒星形成在再电离结束时受到电离背景的抑制。这种平坦化不会出现在较高的红移处。我们为 SFR-M_halo、SFR-M_star 和宽带星等-恒星质量关系提供依赖于红移的拟合函数。我们推导出 z=5-12 时的恒星形成速率密度和恒星质量密度，并表明在 z>8 时非常微弱星系的贡献变得更加重要。此外，我们发现比M_1500~-20更亮的z~6 UV光度函数的下降很大程度上是由于灰尘衰减造成的。比 M_1500=-13 (-17) 更亮的星系大约 37% (54%) 的紫外光度被 z~6 处的尘埃遮蔽。我们的结果与当前数据基本一致，并且可以通过未来的观察进行检验。
We present a suite of cosmological zoom-in simulations at z>5 from the Feedback In Realistic Environments project, spanning a halo mass range M_halo~10^8-10^12 M_sun at z=5. We predict the stellar mass-halo mass relation, stellar mass function, and luminosity function in several bands from z=5-12. The median stellar mass-halo mass relation does not evolve strongly at z=5-12. The faint-end slope of the luminosity function steepens with increasing redshift, as inherited from the halo mass function at these redshifts. Below z~6, the stellar mass function and ultraviolet (UV) luminosity function slightly flatten below M_star~10^4.5 M_sun (fainter than M_1500~-12), owing to the fact that star formation in low-mass halos is suppressed by the ionizing background by the end of reionization. Such flattening does not appear at higher redshifts. We provide redshift-dependent fitting functions for the SFR-M_halo, SFR-M_star, and broad-band magnitude-stellar mass relations. We derive the star formation rate density and stellar mass density at z=5-12 and show that the contribution from very faint galaxies becomes more important at z>8. Furthermore, we find that the decline in the z~6 UV luminosity function brighter than M_1500~-20 is largely due to dust attenuation. Approximately 37% (54%) of the UV luminosity from galaxies brighter than M_1500=-13 (-17) is obscured by dust at z~6. Our results broadly agree with current data and can be tested by future observations.