z~2盘宇宙学模拟中的短寿命恒星形成巨块
Short-lived star-forming giant clumps in cosmological simulations of z~2 disks
摘要：
许多观测到的大质量恒星形成z \approx 2星系都是表现出不规则形态的大圆盘，\sim 1 kpc，\sim 10^（8-10）Msun团块。我们提出了迄今为止最大的高分辨率宇宙学SPH模拟样本，该模拟放大了z \approx 2处\sim 10 ^（12）Msun晕中单个M* \sim 10 ^（10.5）Msun星系的形成。我们的代码包括强烈的恒星反馈参数化为动量驱动的星系风。该模型再现了这类星系的许多特征，如星系团的形态、平滑而单调的速度梯度、高气体分数（\sim 50%）和高比恒星形成率（\gtrsim 1Gyr^（-1））。根据最近的模型，巨大的团块（Mclump \sim（5 × 10^8 -10^9）Msun）通过引力不稳定性就地形成。然而，星系风对它们随后的演化至关重要。我们获得的巨大团块是短暂的，并被风驱动的质量损失所破坏。它们并不像最近忽略强风的研究所建议的那样，形成或迁移到星系中心。通过从现象学上实现从高红移星系，特别是从个别星系团观察到的风，我们的模拟再现了很好的新观测约束的星系团运动学和星系团年龄。特别是，在我们的模拟中再现了较老的团块似乎更靠近星系中心的观察结果，这是由于盘的内部向外形成而不是向内的团块迁移。
英文摘要：
Many observed massive star-forming z\approx2 galaxies are large disks that exhibit irregular morphologies, with \sim1kpc, \sim10^(8-10)Msun clumps. We present the largest sample to date of high-resolution cosmological SPH simulations that zoom-in on the formation of individual M*\sim10^(10.5)Msun galaxies in \sim10^(12)Msun halos at z\approx2. Our code includes strong stellar feedback parameterized as momentum-driven galactic winds. This model reproduces many characteristic features of this observed class of galaxies, such as their clumpy morphologies, smooth and monotonic velocity gradients, high gas fractions (f_g\sim50%) and high specific star-formation rates (\gtrsim1Gyr^(-1)). In accord with recent models, giant clumps (Mclump\sim(5x10^8-10^9)Msun) form in-situ via gravitational instabilities. However, the galactic winds are critical for their subsequent evolution. The giant clumps we obtain are short-lived and are disrupted by wind-driven mass loss. They do not virialise or migrate to the galaxy centers as suggested in recent work neglecting strong winds. By phenomenologically implementing the winds that are observed from high-redshift galaxies and in particular from individual clumps, our simulations reproduce well new observational constraints on clump kinematics and clump ages. In particular, the observation that older clumps appear closer to their galaxy centers is reproduced in our simulations, as a result of inside-out formation of the disks rather than inward clump migration.
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。
