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arXiv 2411.09522astro-ph.GA
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COSMOS2020:解开0.4<z<4星系恒星形成活动中质量与环境的作用

COSMOS2020: Disentangling the Role of Mass and Environment in Star Formation Activity of Galaxies at $0.4<z<4$

Sina Taamoli, Negin Nezhad, Bahram Mobasher, Faezeh Manesh, Nima Chartab, John R. Weaver, Peter L. Capak, Caitlin M. Casey, Ghassem Gozaliasl, Kasper E. Heintz,… 展开作者

Sina Taamoli, Negin Nezhad, Bahram Mobasher, Faezeh Manesh, Nima Chartab, John R. Weaver, Peter L. Capak, Caitlin M. Casey, Ghassem Gozaliasl, Kasper E. Heintz, Olivier Ilbert, Jeyhan S. Kartaltepe, Henry J. McCracken, David B. Sanders, Nicholas Scoville, Sune Toft, Darach Watson

AI总结:

基于COSMOS2020星表约21万个星系,研究0.4<z<4范围内质量与环境对恒星形成活动的影响,发现低红移时两者均抑制恒星形成,高红移时环境效应逆转并促进恒星形成,且质量始终是主导淬灭因素。

摘要:

内部因素和环境因素在星系恒星形成活动中的作用仍存在争议,尤其是在较高红移处。利用COSMOS星表的最新版本COSMOS2020以及我们此前研究中的密度测量,我们解开了环境与恒星质量对红移范围0.4<z<4内约210,000个星系样本的恒星形成率(SFR)和比恒星形成率(sSFR)的影响,并在三个宇宙时期呈现我们的发现:1)在z~1之前,平均SFR和sSFR在极高密度环境和分布的高质量端下降,这主要是由于大质量宁静星系群体的存在;2)在1<z<2时,环境依赖性减弱,而质量仍是恒星形成活动的主导因素;3)在z~2之后,我们的样本以恒星形成星系为主,我们观察到与本地宇宙中所见趋势的逆转:平均SFR随环境密度增加而升高。我们的分析表明,在所有红移处,环境淬灭效率和质量淬灭效率都随恒星质量增加而提高,且与大质量星系中的环境效应相比,质量是主导的淬灭因素。在2<z<4处,环境淬灭效率的负值表明,致密环境中恒星形成星系的比例超过了低密度区域中的比例,这可能是由于冷气体的更大可获得性、更高的并合率以及触发恒星形成活动的潮汐效应。

英文摘要:

The role of internal and environmental factors in the star formation activity of galaxies is still a matter of debate, particularly at higher redshifts. Leveraging the most recent release of the COSMOS catalog, COSMOS2020, and density measurements from our previous study we disentangle the impact of environment and stellar mass on the star formation rate (SFR), and specific SFR (sSFR) of a sample of $\sim 210,000$ galaxies within redshift range $0.4< z < 4$ and present our findings in three cosmic epochs: 1) out to $z\sim 1$, the average SFR and sSFR decline at extremely dense environments and high mass end of the distribution which is mostly due to the presence of the massive quiescent population; 2) at $1<z<2$, the environmental dependence diminishes, while mass is still the dominant factor in star formation activity; 3) beyond $z\sim 2$, our sample is dominated by star-forming galaxies and we observe a reversal of the trends seen in the local universe: the average SFR increases with increasing environmental density. Our analysis shows that both environmental and mass quenching efficiencies increase with stellar mass at all redshifts, with mass being the dominant quenching factor in massive galaxies compared to environmental effects. At $2<z<4$, negative values of environmental quenching efficiency suggest that the fraction of star-forming galaxies in dense environments exceeds that in less dense regions, likely due to the greater availability of cold gas, higher merger rates, and tidal effects that trigger star formation activity.

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。

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