Feedback and the structure of simulated galaxies at redshift z=2
Feedback and the structure of simulated galaxies at redshift z=2
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红移 z=2 时的反馈和模拟星系的结构
DOI：
10.1111/j.1365-2966.2010.17391.x
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发表时间：
2010
影响因子：
4.8
通讯作者：
C. Booth
中科院分区：
文献类型：
--
作者：
L. Sales;J. Navarro;J. Schaye;C. D. Vecchia;V. Springel;C. Booth
我们利用压倒性大型模拟（owl）项目的宇宙学n体/气体动力学运行研究了模拟高红移星系的性质。这些运行对比了几种不同效果的反馈实现：从没有反馈，到超新星驱动的风，再到强大的活动星系核（AGN）驱动的流出。这些不同的反馈模型导致了z = 2处明亮星系的丰度和结构特性的巨大变化。与早期的工作一致，低效或没有反馈的模型导致大质量致密星系的形成，这些星系收集了每个晕中所有可用重子的很大一部分（超过50%）。提高反馈效率降低了重子质量，增大了模拟星系的大小。与没有反馈的情况相比，一个包含超新星驱动的气体流出的模型，在agn的能量输出的帮助下，减少了大约10倍的星系质量。其他模型给出的结果则介于这两个极端之间。尽管在星系形成效率上存在很大差异，一个星系的净比角动量平均大约是其周围晕的一半，与晕质量（在探测范围内）和反馈方案无关。因此，反馈对星系重子质量的影响要比其自旋严重得多。反馈诱导了角动量含量和星系质量之间的强相关性，这在星系的尺度关系和形态上留下了印记。令人鼓舞的是，我们发现星系盘在中等反馈运行中很常见，在光晕中心的所有星系中，通常有50%的星系组成，其质量超过1011 m圆点。在这种运行中形成的模拟星系的大小、恒星质量和旋转速度在z = 2时介于大型恒星形成盘和紧凑的早期型星系之间。一旦这些稀有天体的详细丰度和结构特性得到很好的确定，就有可能利用它们来衡量高红移星系形成过程中反馈的总体效果。
We study the properties of simulated high-redshift galaxies using cosmological N-body/gasdynamical runs from the OverWhelmingly Large Simulations (OWLS) project. The runs contrast several feedback implementations of varying effectiveness: from no feedback, to supernova-driven winds to powerful active galactic nucleus (AGN)-driven outflows. These different feedback models result in large variations in the abundance and structural properties of bright galaxies at z = 2. In agreement with earlier work, models with inefficient or no feedback lead to the formation of massive compact galaxies collecting a large fraction (upwards of 50 per cent) of all available baryons in each halo. Increasing the efficiency of feedback reduces the baryonic mass and increases the size of simulated galaxies. A model that includes supernova-driven gas outflows aided by the energetic output of AGNs reduces galaxy masses by roughly a factor of similar to 10 compared with the no-feedback case. Other models give results that straddle these two extremes. Despite the large differences in galaxy formation efficiency, the net specific angular momentum of a galaxy is, on average, roughly half that of its surrounding halo, independent of halo mass (in the range probed) and of the feedback scheme. Feedback thus affects the baryonic mass of a galaxy much more severely than its spin. Feedback induces strong correlations between angular momentum content and galaxy mass that leave their imprint on galaxy scaling relations and morphologies. Encouragingly, we find that galaxy discs are common in moderate-feedback runs, making up typically similar to 50 per cent of all galaxies at the centres of haloes with virial mass exceeding similar to 1011 M-circle dot. The size, stellar masses and circular speeds of simulated galaxies formed in such runs have properties in between those of large star-forming discs and of compact early-type galaxies at z = 2. Once the detailed abundance and structural properties of these rare objects are well established, it may be possible to use them to gauge the overall efficacy of feedback in the formation of high-redshift galaxies.
DOI：
10.1111/j.1365-2966.2009.15034.x
发表时间：
2008-08
影响因子：
4.8
作者：
K. Dolag;S. Borgani;S. Borgani;S. Borgani;G. Murante;V. Springel
通讯作者：
K. Dolag;S. Borgani;S. Borgani;S. Borgani;G. Murante;V. Springel