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arXiv 2006.09159astro-ph.GAastro-ph.CO
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从透镜状星系到蓝致密矮星系：恒星质量分数由盘引力不稳定性调控

From lenticulars to blue compact dwarfs: the stellar mass fraction is regulated by disc gravitational instability

Alessandro B. Romeo, Oscar Agertz, Florent Renaud

备注：
MNRAS, in press. Fig. 4, Sect. 4 and the last itemized paragraph of Sect. 5 are new, and demonstrate the importance of our results for the simulation community
发表信息：
MNRAS, 499, 5656 (2020)
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AI总结：

本研究利用大质量星系样本对比分析恒星-晕质量关系，提出基于盘引力不稳定性的新标度关系，证明其调控恒星质量分数演化，且该过程在各类盘星系中具有普适性。

摘要：

恒星-晕质量关系（SHMR）不仅是我们获取星系与其暗物质晕之间关联信息的主要来源之一，也是衡量星系形成模型性能的重要指标。本文我们使用了同时拥有高质量旋转曲线和近红外表面测光的最大规模星系样本之一，对SHMR开展了详细的对比分析。我们的分析表明，各类常用的SHMR形式之间存在显著的统计学差异，并展现了一种新的、具有物理动机的标度关系的预测能力——该关系通过盘引力不稳定性，将恒星质量分数（$M_{\u27e9}/M_{\u210d}$）与恒星比角动量（$j_{\u27e9}$）、恒星径向速度弥散（$σ_{\u27e9}$）联系起来。利用这一关系，我们证明了两点：（i）即便对于最先进的宇宙流体动力学模拟而言，重现星系形成的效率也极具挑战性；（ii）恒星质量分数的演化由盘引力不稳定性调控：当$M_{\u27e9}/M_{\u210d}$发生变化时，$j_{\u27e9}$和$σ_{\u27e9}$也会按照我们的标度关系预测的那样发生变化，从而抹去了这一演化的“记忆”。这意味着，在所有形态类型的盘星系中，从透镜状星系到蓝致密矮星系，盘引力不稳定性过程都呈现出惊人的一致性。具体而言，Toomre $Q$值的宇宙学弥散为0.2 dex，这对恒星和原子气体来说都是一个普适值。

英文摘要：

The stellar-to-halo mass relation (SHMR) is not only one of the main sources of information we have on the connection between galaxies and their dark matter haloes, but also an important indicator of the performance of galaxy formation models. Here we use one of the largest sample of galaxies with both high-quality rotation curves and near-infrared surface photometry, and perform a detailed comparative analysis of the SHMR. Our analysis shows that there are significant statistical differences between popular forms of the SHMR, and illustrates the predictive power of a new physically motivated scaling relation, which connects the stellar mass fraction ($M_{\star}/M_{\mathrm{h}}$) to the stellar specific angular momentum ($j_{\star}$) and the stellar radial velocity dispersion ($σ_{\star}$) via disc gravitational instability. Making use of such a relation, we demonstrate (i) how challenging it is to reproduce the efficiency of galaxy formation even for state-of-the-art cosmological hydrodynamical simulations, and (ii) that the evolution of the stellar mass fraction is regulated by disc gravitational instability: when $M_{\star}/M_{\mathrm{h}}$ varies, $j_{\star}$ and $σ_{\star}$ also vary as predicted by our scaling relation, thus erasing the memory of such evolution. This implies that the process of disc gravitational instability is intriguingly uniform across disc galaxies of all morphological types: from lenticulars to blue compact dwarfs. In particular, the cosmic variance of Toomre's $Q$ is 0.2 dex, a universal value for both stars and atomic gas.

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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