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arXiv 1801.09754astro-ph.GA
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Horizon-AGN模拟中大质量早型星系的总密度分布:AGN反馈的影响及与观测的比较

Total density profile of massive early-type galaxies in Horizon-AGN simulation: impact of AGN feedback and comparison with observations

S. Peirani, A. Sonnenfeld, R. Gavazzi, M. Oguri, Y. Dubois, J. Silk, C. Pichon, J. Devriendt, S. Kaviraj

摘要:

利用两个大尺度宇宙流体动力学模拟Horizon-AGN(H-AGN)和Horizon-noAGN(H-noAGN,no AGN feedback),研究了AGN反馈的典型亚网格模型如何影响大质量早型星系(M*>10^11 Msun)有效半径处总密度剖面(暗物质+恒星)的演化.我们研究了z~0.3处质量加权密度斜率γ '_tot与有效半径、星系质量和宿主晕质量的依赖关系,发现包含活动星系核反馈总是导致与观测值和趋势更好的一致。我们的分析还表明,活动星系核反馈的列入有利于一个强相关性的gamma '_tot和密度斜率的暗物质组件,而在活动星系核活动的情况下,gamma'_tot是相当强的相关性的恒星组件的密度斜率。最后,我们发现从我们的星系样本中得到的gamma '_tot从z=2增加到z=0,与预期的观测趋势非常一致。推导出的斜率比包含活动星系核时的数据略低,因为模拟的星系往往过于延伸,特别是质量最小的星系。然而,没有AGN反馈的模拟致密星系的gamma '_tot值与观测值相比明显过高。

英文摘要:

Using the two large cosmological hydrodynamical simulations, Horizon-AGN (H-AGN) and Horizon-noAGN (H-noAGN, no AGN feedback), we investigate how a typical sub-grid model for AGN feedback affects the evolution of the total density profiles (dark matter + stars) at the effective radius of massive early-type galaxies (M*>10^11 Msun). We have studied the dependencies of the mass-weighted density slope gamma'_tot with the effective radius, the galaxy mass and the host halo mass at z~0.3 and found that the inclusion of AGN feedbackalways leads to a much better agreement with observational values and trends. Our analysis suggests also that the inclusion of AGN feedback favours a strong correlation between gamma'_tot and the density slope of the dark matter component while, in the absence of AGN activity, gamma'_tot is rather strongly correlated with the density slope of the stellar component. Finally, we find that gamma'_tot derived from our samples of galaxies increases from z=2 to z=0,in good agreement with the expected observational trend. The derived slopes are slightly lower than in the data when AGN is included because the simulated galaxies tend to be too extended, especially the least massive ones. However, the simulated compact galaxies without AGN feedback have gamma'_tot values that are significantly too high compared to observations.

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。

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