How is star formation quenched in massive galaxies
How is star formation quenched in massive galaxies
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DOI：
10.1111/j.1365-2966.2010.16961.x
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发表时间：
2010-01
影响因子：
4.8
通讯作者：
J. Gabor;R. Davé;K. Finlator;K. Finlator;B. Oppenheimer;B. Oppenheimer
中科院分区：
文献类型：
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作者：
J. Gabor;R. Davé;K. Finlator;K. Finlator;B. Oppenheimer;B. Oppenheimer
当今观测到的星系颜色的双峰性长期以来一直是分层星系形成模型的一个挑战，因为它需要一些物理过程来淬灭（并保持淬灭）大质量星系中的恒星形成。在这里，我们通过对宇宙流体动力学模拟中的星系恒星形成历史进行后处理来检查猝灭的现象学模型，该模拟很好地再现了恒星形成星系的观测结果。我们考虑基于主要合并、光环质量阈值、气体温度阈值及其变体的淬火配方。我们将由此产生的模拟恒星形成历史与观测到的 g r 颜色星等图以及来自 SDSS 的红色和蓝色光度函数进行比较。合并和光环质量猝灭情景各自产生了独特的红色序列和蓝色星系云，这些星系与数据广泛一致，尽管只是在相当极端的假设下。然而，详细而言，两种情况下模拟的红色序列斜率和幅度都有些差异，也许可以追溯到模拟星系中的低金属丰度。合并猝灭会产生更大质量的蓝色星系、更早的猝灭以及更多年轻恒星的霜化；与相关数据相比，倾向于合并而不是光晕质量淬灭。尽管物理驱动的猝灭模型可以产生红色序列，但仍然存在有趣的一般差异，这表明需要额外的物理学来重现红色和死亡星系的恒星形成和富集历史。
The bimodality in observed present-day galaxy colours has long been a challenge for hierarchical galaxy formation models, as it requires some physical process to quench (and keep quenched) star formation in massive galaxies. Here we examine phenomenological models of quenching by post-processing the star formation histories of galaxies from cosmological hydrodynamic simulations that reproduce observations of star-forming galaxies reasonably well. We consider recipes for quenching based on major mergers, halo mass thresholds, gas temperature thresholds, and variants thereof. We compare the resulting simulated star formation histories to observed g r colour-magnitude diagrams and red and blue luminosity functions from SDSS. The merger and halo mass quenching scenarios each yield a distinct red sequence and blue cloud of galaxies that are in broad agreement with data, albeit only under rather extreme assumptions. In detail, however, the simulated red sequence slope and amplitude in both scenarios are somewhat discrepant, perhaps traceable to low metallicities in simulated galaxies. Merger quenching produces more massive blue galaxies, earlier quenching, and more frosting of young stars; comparing to relevant data tends to favor merger over halo mass quenching. Although physically-motivated quenching models can produce a red sequence, interesting generic discrepancies remain that indicate that additional physics is required to reproduce the star formation and enrichment histories of red and dead galaxies.