arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新,休息一下吧,周末愉快~~
arXiv 1609.04402astro-ph.GA
收藏

$Λ$ CDM允许的最大质量星系和黑洞

The Most Massive Galaxies and Black Holes Allowed by $Λ$CDM

Peter Behroozi, Joseph Silk

摘要:

给定星系的恒星质量,它的宿主晕质量有一个下限,来自宇宙重子分数和已知的重子物理学。在z>4时,星系恒星质量函数对晕数密度的下限接近预期的$Λ$ CDM晕质量函数。高红移星系恒星质量函数因此可以对大质量晕的数密度进行有趣的限制,否则很难测量。虽然z<8时的晕质量函数与观测到的星系恒星质量一致,但如果星系重子转换效率随红移增加,JWST和WFIRST将使可用约束的红移范围增加一倍以上。我们计算最大星系恒星质量作为红移的函数,从$Λ$ CDM给出预期的晕数密度。我们将类似的论证应用于黑洞。如果他们的维里质量估计是准确的,单是数密度约束就表明类星体SDSS J1044-0125和SDSS J010013.02+280225.8可能有黑洞质量-恒星质量比高于中值z=0的关系,证实了劳尔偏差的预期。最后,我们提出了一个公共代码来评估的概率,显然$Λ$ CDM不一致的高质量晕被检测到的多重调查和观测误差的综合影响。

英文摘要:

Given a galaxy's stellar mass, its host halo mass has a lower limit from the cosmic baryon fraction and known baryonic physics. At z>4, galaxy stellar mass functions place lower limits on halo number densities that approach expected $Λ$CDM halo mass functions. High-redshift galaxy stellar mass functions can thus place interesting limits on number densities of massive haloes, which are otherwise very difficult to measure. Although halo mass functions at z<8 are consistent with observed galaxy stellar masses if galaxy baryonic conversion efficiencies increase with redshift, JWST and WFIRST will more than double the redshift range over which useful constraints are available. We calculate maximum galaxy stellar masses as a function of redshift given expected halo number densities from $Λ$CDM. We apply similar arguments to black holes. If their virial mass estimates are accurate, number density constraints alone suggest that the quasars SDSS J1044-0125 and SDSS J010013.02+280225.8 likely have black hole mass -- stellar mass ratios higher than the median z=0 relation, confirming the expectation from Lauer bias. Finally, we present a public code to evaluate the probability of an apparently $Λ$CDM-inconsistent high-mass halo being detected given the combined effects of multiple surveys and observational errors.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑