arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2401.06211astro-ph.GA
收藏

追溯宇宙时间中的淬灭历程

Tracing the Quenching Journey across Cosmic Time

Gabriella De Lucia, Fabio Fontanot, Lizhi Xie, Michaela Hirschmann

AI总结:

本文介绍GAEA星系形成模型的最新版本,通过改进AGN反馈、类星体风和卫星星系气体剥离处理,显著提升了对星系淬灭比例和数密度的预测精度,并与观测数据高度吻合。

摘要:

我们介绍了GAEA星系形成模型的最新版本。我们的新模型结合了(i)对活动星系核(AGN)反馈的更新处理,包括对超大质量黑洞上冷气体吸积的改进建模以及类星体风的显式实现;以及(ii)对卫星星系冷热气体剥离的改进建模。我们表明,我们的最新模型预测的比恒星形成率(specific SFR)分布与本地宇宙的观测测量结果高度一致。我们更新后的模型预测的淬灭比例与高达z~3-4的数据非常吻合,并且在低恒星质量端预测的淬灭星系数密度出现拐点,这与当前的观测估计在定性上一致。我们表明,相对于我们模型的先前版本,行为改善的主要原因是针对低星系质量(<10^10 Msun)卫星星系的更新处理,以及在中等至大恒星质量(>10^10 Msun)范围内纳入类星体风。然而,我们表明,由于我们将冷气体显式划分为原子和分子组分,从而改进了恒星形成阈值的处理,这在抑制大质量星系中过度的残余恒星形成方面也发挥了重要作用。虽然我们的分析基于利用恒星形成率信息的宁静星系选择,但我们证明,不同(颜色-颜色)选择方法的影响并不显著,至少在高于当前巡天完备极限的星系中是如此。我们的新模型预测在z>3处的大质量宁静星系数密度是最近发表的模型中最大的。然而,我们的模型预测似乎仍低于JWST之后的观测测量结果。我们表明,预期的宇宙方差很大,可以轻松容纳一些最新的测量结果。

英文摘要:

We present the latest version of the GAEA model of galaxy formation. Our new model combines (i) an updated treatment of AGN feedback including an improved modelling of cold gas accretion on super-massive BHs and an explicit implementation of quasar winds; and (ii) an improved modelling of cold and hot gas stripping from satellite galaxies. We show that our latest model predicts specific SFR distributions that are in remarkable agreement with observational measurements in the local Universe. Our updated model predicts quenched fractions that are in very nice agreement with data up to z~3-4, and a turn-over of the number densities of quenched galaxies at low stellar masses that is in qualitative agreement with current observational estimates. We show that the main reasons for the improved behaviour with respect to previous renditions of our model are the updated treatment for satellites at low galaxy masses (<10^10 Msun) and the inclusion of quasar winds at intermediate to large stellar masses (>10^10 Msun). However, we show that the better treatment of the star formation threshold, due to our explicit partitioning of the cold gas in its atomic and molecular components, also plays an important role in suppressing excessive residual star formation in massive galaxies. While our analysis is based on a selection of quiescent galaxies that takes advantage of the information about their SFR, we demonstrate that the impact of a different (colour-colour) selection is not significant, at least for galaxies above the completeness limits of current surveys. Our new model predicts number densities of massive quiescent galaxies at z>3 that are the largest among recently published models. Yet, our model predictions appear still to be below post-JWST observational measurements. We show that the expected cosmic variance is large, and can easily accommodate some of the most recent measurements.

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。

↑