An Empirical Model for the Galaxy Luminosity and Star-Formation Rate Function at High Redshift
An Empirical Model for the Galaxy Luminosity and Star-Formation Rate Function at High Redshift
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DOI：
10.1093/mnras/stv2469
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发表时间：
2015-07
期刊：
影响因子：
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通讯作者：
N. Mashian;P. Oesch;A. Loeb
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作者：
N. Mashian;P. Oesch;A. Loeb
利用最新测量的早期星系的紫外光度函数(LFS)和尘埃估计，我们得到了更新的z~4-8处尘埃校正恒星形成率函数(SFRF)，并对其进行了模拟，以预测星系向更高红移z>；8的演化。我们使用丰度匹配技术，通过将z~4-8处观测到的恒星形成率函数的形状映射到晕质量函数，来校准星系恒星形成率(SFR)与宿主晕质量M$(H)之间的关系。由此产生的标度律在这个红移范围内基本保持不变。我们用平均的SFR-Mh关系再现了观测到的410的SFR函数，表明JWST将能够通过一个大规模的金库大小的计划来探测到z15以外的星系。我们还得到了恒星形成率、密度和相关的星系再电离历史的红移演化。集成到当前HUDF12/XDF探测极限(M$_uv}~-17.7mag)的模型导致SFRd在高红移时衰减为(1+z)$^-10.4pm0.3}$，并且不能重现观测到的CMB电子散射光学厚度$0.066至1$\sigma$。另一方面，我们发现，如果星系的SfR远低于当前的探测极限(M<sup>uv</sup>-5.7mag)，则宇宙的电离度为z6.5，光学厚度为0.054美元，这与最近在1西格玛水平上得到的普朗克值一致。
Using the most recent measurements of the ultraviolet (UV) luminosity functions (LFs) and dust estimates of early galaxies, we derive updated dust-corrected star-formation rate functions (SFRFs) at z~4-8, which we model to predict the evolution to higher redshifts, z>8. We employ abundance matching techniques to calibrate a relation between galaxy star formation rate (SFR) and host halo mass M$_{h}$ by mapping the shape of the observed SFRFs at z~4-8 to that of the halo mass function. The resulting scaling law remains roughly constant over this redshift range. We apply the average SFR-M$_{h}$ relation to reproduce the observed SFR functions at 4 10 indicate that JWST will be able to detect galaxies out to z~15 with an extensive treasury sized program. We also derive the redshift evolution of the star formation rate density and associated reionization history by galaxies. Models which integrate down to the current HUDF12/XDF detection limit (M$_{UV}$ ~ -17.7 mag) result in a SFRD that declines as (1+z)$^{-10.4\pm0.3}$ at high redshift and fail to reproduce the observed CMB electron scattering optical depth, $\tau$ ~ 0.066, to within 1$\sigma$. On the other hand, we find that the inclusion of galaxies with SFRs well below the current detection limit (M$_{UV}$ < -5.7 mag) leads to a fully reionized universe by z ~ 6.5 and an optical depth of $\tau$ ~ 0.054, consistent with the recently derived Planck value at the 1$\sigma$ level.