前二十亿年中的星系：基于面密度调制的恒星形成与反馈的早期形成和熄灭
Galaxies in the first two billion years: Earlier formation and quenching with surface-density modulated star formation and feedback
- Max Planck Institute for Astrophysics（马克斯·普朗克天体物理学研究所）
- Ludwig-Maximilians-Universität München（慕尼黑大学）
- Argelander-Institut für Astronomie（阿根德纳天文学研究所）
机构由 AI 辅助整理，请以论文原文为准。
AI总结：
本研究通过L-Galaxies半解析模型，以局部气体面密度调控恒星形成与反馈，显著提高了高红移大质量明亮星系的丰度，并缓解了模型与JWST观测间的矛盾。
AI中文摘要：
JWST揭示了宇宙历史前二十亿年中存在的大质量、紫外明亮、致密且部分已熄灭的星系，这对当前的星系形成模型提出了挑战。我们开发了一个扩展的L-Galaxies半解析模型，运行在MillenniumTNG暗物质-only模拟上，并追踪了$0 \le z \lesssim 15$范围内的星系演化。该模型将恒星形成效率和恒星反馈能量的耦合与局部冷气体面密度联系起来，使得在致密气体中恒星形成高效而反馈无效。我们包含了耗散性富气体并合以及恒星和气体盘中的盘不稳定性。所有参数通过一个新的并行化马尔可夫链蒙特卡洛框架，同时针对$z\simeq0-4$的恒星质量函数和熄灭比例以及$z\simeq11-12$的紫外光度函数进行校准。该模型再现了直到$z\approx 11$的恒星质量函数，并在$z\gtrsim9$时将大质量且紫外明亮星系的数量比旧版本提高了最多两个数量级。尽管AGN反馈方案未变，但增强的核球增长和黑洞供能使得$z\simeq3-8$的大质量熄灭星系数量增加了两个数量级，而耗散性并合产生了致密的遗迹，其紫外尺寸-光度关系与$z\simeq10-13$的观测相符。在低红移下，星系的大小、冷气体含量、金属丰度、径向轮廓和形态仍与观测一致。我们的结果表明，通过局部气体面密度调节恒星形成和反馈，可以显著减少宇宙黎明时期模型与JWST观测之间的张力，而无需修改初始质量函数、非标准宇宙学或新的AGN物理。
英文摘要：
JWST has revealed massive, UV-bright, compact, and in some cases quenched galaxies in the first two billion years of cosmic history, challenging current galaxy formation models. We develop an extended L-Galaxies semi-analytic model, run on the MillenniumTNG dark-matter-only simulation, and follow galaxy evolution over $0 \le z \lesssim 15$. The model ties the star formation efficiency and the coupling of stellar feedback energy to the local cold gas surface density, making star formation efficient and feedback ineffective in dense gas. We include dissipative gas-rich mergers and disc instabilities in stellar and gaseous discs. All parameters are calibrated simultaneously against stellar mass functions and quenched fractions at $z\simeq0-4$ and UV luminosity functions at $z\simeq11-12$ with a new parallelised Markov chain Monte Carlo framework. The model reproduces the stellar mass function up to $z\approx 11$ and increases the abundance of massive and UV-bright galaxies at $z\gtrsim9$ by up to two orders of magnitude over the legacy version. Although the AGN feedback prescription is unchanged, the enhanced bulge growth and black hole fuelling make massive quenched galaxies at $z\simeq3-8$ two orders of magnitude more abundant, while dissipative mergers produce compact remnants with UV size-luminosity relations matching observations at $z\simeq10-13$. At low redshift, galaxy sizes, cold-gas content, metallicities, radial profiles, and morphologies remain consistent with observations. Our results indicate that the tension between models and JWST observations at cosmic dawn can be substantially reduced by regulating star formation and feedback through the local gas surface density, without a modified initial mass function, non-standard cosmology, or new AGN physics.
