论文标题

$^{3} $ cosmos:跨宇宙时间的分子气体质量和主要序列星系范围的人口普查

A$^{3}$COSMOS: A census on the molecular gas mass and extent of main-sequence galaxies across cosmic time

论文作者

Wang, Tsan-Ming, Magnelli, Benjamin, Schinnerer, Eva, Liu, Daizhong, Modak, Ziad Aziz, Jiménez-Andrade, Eric Faustino, Karoumpis, Christos, Kokorev, Vasily, Bertoldi, Frank

论文摘要

首次限制$> 10^{10} $ m $ _ {\ odot} $ main-sequence(ms)星系$ 0.4 <z <z <3.6 $的质量完成样本的平均质量和范围。我们将基于创新的$ UV $叠加分析应用于大型档案库Atacama大型毫米/亚毫米阵列(ALMA)观测值。这种堆叠分析提供了银河系种群分子气体的平均质量和程度的测量。 MS星系的分子气体质量随红移和恒星质量而演变。在所有恒星群众中,分子气体分数从$ z \ sim3.2 $减少到$ z \ sim0 $。在给定的红移下,MS星系的分子气体分数随着恒星质量的降低,大致与其特定恒星形成速率的速率大致相同。 MS星系的分子气体耗竭时间在$ z> 0.5 $中保持大致恒定,价值为300--500 MYR,但从$ z \ sim0.5 $增加到$ z \ sim0 $,增加了3倍。 MS星系的分子气体耗竭时间的这种演变可以从它们的分子气表面密度的演变以及看似通用的仅MS $σ_{M _ {M _ {\ rm mol}} - σ_{\ = _ {\ rm sfr} $与推断的1.13,i.13,i.ee.ee.,k的相关性。 MS星系的远红外尺寸与红移或恒星质量没有显着演化,平均圆形半光线半径为2.2 kpc。最后,我们的平均分子气体质量低于以前的估计,这可能是由于文献研究偏向具有大量气体储层的单独检测的MS星系。首先,MS星系的分子气体含量调节其在宇宙时间的恒星形成,而其星形形成效率的变化起着次要作用。尽管它们的气体含量和SFR的演变很大,但MS星系还是沿看似通用的仅MS-KS关系进化。

To constrain for the first time the mean mass and extent of the molecular gas of a mass-complete sample of $>10^{10}$M$_{\odot}$ main-sequence (MS) galaxies at $0.4<z<3.6$. We apply an innovative $uv$-based stacking analysis to a large set of archival Atacama Large Millimeter/submillimeter Array (ALMA) observations. This stacking analysis provides measurements of the mean mass and extent of the molecular gas of galaxy populations. The molecular gas mass of MS galaxies evolves with redshift and stellar mass. At all stellar masses, the molecular gas fraction decreases by a factor of 24 from $z\sim3.2$ to $z\sim0$. At a given redshift, the molecular gas fraction of MS galaxies decreases with stellar mass, at roughly the same rate as their specific star formation rate decreases. The molecular gas depletion time of MS galaxies remains roughly constant at $z>0.5$ with a value of 300--500 Myr, but increases by a factor of 3 from $z\sim0.5$ to $z\sim0$. This evolution of the molecular gas depletion time of MS galaxies can be predicted from the evolution of their molecular gas surface density and a seemingly universal MS-only $Σ_{M_{\rm mol}}-Σ_{\rm SFR}$ relation with an inferred slope of 1.13, i.e., the so-called KS relation. The far-infrared size of MS galaxies shows no significant evolution with redshift or stellar mass, with a mean circularized half-light radius of 2.2 kpc. Finally, our mean molecular gas masses are lower than previous estimates, likely caused by the fact that literature studies were biased towards individually-detected MS galaxies with massive gas reservoirs. To first order, the molecular gas content of MS galaxies regulates their star formation across cosmic time, while variation of their star formation efficiency plays a secondary role. Despite a large evolution of their gas content and SFRs, MS galaxies evolved along a seemingly universal MS-only KS relation.

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