arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 0905.3555astro-ph.CO
收藏

OWLS中z=2的盘星系

Disk galaxies at z=2 in OWLS

Julio F. Navarro, Laura V. Sales, Joop Schaye, Claudio Dalla Vecchia, Volker Springel

摘要:

我们使用OWLS(OverWhelmingly Large Simulations)的宇宙学Nbody/气体动力学模拟研究模拟星系在z=2的属性。我们着重研究了演化恒星的超新星反馈对聚集在1 e 11 - 3e 12 h^{-1}M_ \odot晕中心的星系的重子质量和角动量含量的影响。我们的主要发现是,这样的星系的质量和角动量强烈耦合,在某种程度上,是近似独立的反馈:不同的反馈实施导致,在一个给定的晕,星系质量的变化很大,但离开星系的质量角动量的相关性在很大程度上不变。特别是,星系的角动量与其周围晕的角动量之比(j_d=J_gal/J_vir)与星系质量(以晕的维里质量为单位表示; m_d=M_gal/M_vir)密切相关。这种相关性与星系形成的半解析模型中普遍采用的m_d=j_d假设有很大的不同。我们利用这些结果来推断LCDM方案中所预期的z=2处盘星系的大小,并解释最近的观测结果的扩展盘在z~2

英文摘要:

We use the OWLS (OverWhelmingly Large Simulations) set of cosmological Nbody/gasdynamical simulations to study the properties of simulated galaxies at z=2. We focus on the effect of supernova feedback from evolving stars on the baryonic mass and angular momentum content of galaxies that assemble at the center of 1e11-3e12 h^{-1}M_\odot halos. Our main finding is that the mass and angular momentum of such galaxies are strongly coupled, in a way that is approximately independent of feedback: varying the feedback implementation leads, in a given halo, to large variations in galaxy mass but leaves the galaxy mass-angular momentum correlation largely unaltered. In particular, the ratio between the angular momentum of a galaxy and that of its surrounding halo (j_d=J_gal/J_vir) correlates closely with the galaxy mass (expressed in units of the virial mass of the halo; m_d=M_gal/M_vir). This correlation differs substantially from the m_d=j_d assumption commonly adopted in semianalytic models of galaxy formation. We use these results to infer the sizes of disk galaxies at z=2 expected in the LCDM scenario and to interpret recent observations of extended disks at z~2 by the SINS collaboration

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。

↑