Stellar splashback: the edge of the intracluster light
Stellar splashback: the edge of the intracluster light
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DOI：
10.1093/mnras/staa3590
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发表时间：
2020-10
影响因子：
4.8
通讯作者：
A. Deason;K. Oman;Azadeh Fattahi;M. Schaller;M. Jauzac;Yuanyuan Zhang;M. Montes;Y. Bahé;C. Dalla Vecchia-C.-Dalla Vecchia-2124570738;S. Kay;Tilly A Evans
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文献类型：
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作者：
A. Deason;K. Oman;Azadeh Fattahi;M. Schaller;M. Jauzac;Yuanyuan Zhang;M. Montes;Y. Bahé;C. Dalla Vecchia-C.-Dalla Vecchia-2124570738;S. Kay;Tilly A Evans
我们研究的外围星系团的C-EAGLE模拟量化的恒星和暗物质分布的“边缘”。暗物质中最陡斜率的半径，也被称为回溅半径，位于~ r_200 m;这一特征的强度和位置取决于最近的质量吸积速率，与以前的工作非常一致。有趣的是，恒星的分布（或团内光，ICL）也有一个明确的边缘，这与晕的溅回半径直接相关。因此，检测ICL的边缘可以提供一个独立的测量晕的物理边界，和最近的质量吸积率。我们表明，这些焦散也可以看到在投影密度分布，但必须注意考虑到子结构和其他非扩散材料，这可能会导致偏置和/或削弱最陡的斜率的信号的影响。这对于恒星物质来说尤其重要，因为恒星物质比暗物质有更高的比例被束缚在暗晕中。最后，我们指出，“恒星回溅”特征的位置超出了ICL目前的观测限制，但这些大的投影距离（>>1 Mpc）和低的表面亮度（mu >> 32 mag/arcsec ^[2]）可以通过即将到来的观测设施（如维拉C.鲁宾天文台，南希格雷斯罗马太空望远镜，和欧几里得。
We examine the outskirts of galaxy clusters in the C-EAGLE simulations to quantify the "edges" of the stellar and dark matter distribution. The radius of the steepest slope in the dark matter, otherwise known as the splashback radius, is located at ~r_200m; the strength and location of this feature depends on the recent mass accretion rate, in good agreement with previous work. Interestingly, the stellar distribution (or intracluster light, ICL) also has a well-defined edge, which is directly related to the splashback radius of the halo. Thus, detecting the edge of the ICL can provide an independent measure of the physical boundary of the halo, and the recent mass accretion rate. We show that these caustics can also be seen in the projected density profiles, but care must be taken to account for the influence of substructures and other non-diffuse material, which can bias and/or weaken the signal of the steepest slope. This is particularly important for the stellar material, which has a higher fraction bound in subhaloes than the dark matter. Finally, we show that the "stellar splashback" feature is located beyond current observational constraints on the ICL, but these large projected distances (>>1 Mpc) and low surface brightnesses (mu >> 32 mag/arcsec^2) can be reached with upcoming observational facilities such as the Vera C. Rubin Observatory, the Nancy Grace Roman Space Telescope, and Euclid.