A semi-analytical model for the formation and evolution of radio relics in galaxy clusters
A semi-analytical model for the formation and evolution of radio relics in galaxy clusters
复制标题
星系团中射电遗迹形成和演化的半解析模型
DOI：
10.1093/mnras/stac2694
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发表时间：
2022-09
影响因子：
4.8
通讯作者：
Zheng Xianzhong
中科院分区：
文献类型：
--
作者：
Zhou Yihao;Xu Haiguang;Zhu Zhenghao;Zhao Yuanyuan;Fan Shida;Shan Chenxi;Zhu Yongkai;Hao Lei;Ji Li;Zhang Zhongli;Zheng Xianzhong
射电遗迹是位于星系团外围区域的mpc大小的同步加速器源。基于弥漫性激波加速（DSA）情景的模型已被广泛接受来解释射电遗迹的形成。然而，这些模型面临的一个关键挑战是，大多数观测到的冲击似乎太弱，无法产生可探测的辐射，除非化石电子（一群先前已经加速的温和高能电子）被包括在模型中。为了解决这一问题，我们提出了一种新的半解析模型，将化石相对论电子引入到DSA理论中来描述无线电遗迹的形成和演化，该模型受到14个观测遗迹样本的约束，并采用Press-Schechter形式分别模拟了50、158和1400 MHz波段20°× 20°天空场的遗迹。结果表明，化石电子对射电辐射的贡献很大，在158 MHz处产生的辐射比单纯热电子产生的辐射亮4个数量级，模拟的射电遗迹目录的功率分布与观测到的P1400-Mvir关系相符。我们预测Mvir>1.2×1014M⊙的7.1%星团将拥有158mhz的遗迹，这与LOFAR 2米巡天第二次数据发布的结果（10±6%）一致。我们还发现，在未来的再电离实验中，射电遗迹可能会造成严重的前景污染，类似于射电晕的污染。活动星系核（agn）提供种子化石相对论性电子的可能性是通过计算激波在传播过程中预期遇到的无线电响亮agn的数量来评估的。
Radio relics are Mpc-sized synchrotron sources located in the peripheral regions of galaxy clusters. Models based on the diffuse shock acceleration (DSA) scenario have been widely accepted to explain the formation of radio relics. However, a critical challenge to these models is that most observed shocks seem too weak to generate detectable emission, unless fossil electrons, a population of mildly energetic electrons that have been accelerated previously, are included in the models. To address this issue, we present a new semi-analytical model to describe the formation and evolution of radio relics by incorporating fossil relativistic electrons into DSA theory, which is constrained by a sample of 14 observed relics, and employ the Press-Schechter formalism to simulate the relics in a 20° × 20° sky field at 50, 158, and 1400 MHz, respectively. Results show that fossil electrons contribute significantly to the radio emission, which can generate radiation four orders of magnitude brighter than that solely produced by thermal electrons at 158 MHz, and the power distribution of our simulated radio relic catalogue can reconcile the observed P1400-Mvir relation. We predict that 7.1 per cent clusters with Mvir>1.2×1014M⊙ would host relics at 158 MHz, which is consistent with the result of 10±6 per cent given by the Second Data Release of the LOFAR Two-meter Sky Survey. It is also found that radio relics are expected to cause severe foreground contamination in future epoch of reionization experiments, similar to that of radio haloes. The possibility of active galactic nuclei (AGNs) providing seed fossil relativistic electrons is evaluated by calculating the number of radio-loud AGNs that a shock is expected to encounter during its propagation.
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DOI：
10.1007/0-306-48096-4_1
发表时间：
2001-05
期刊：
arXiv: Astrophysics
影响因子：
--
作者：
C. Sarazin
通讯作者：
C. Sarazin
DOI：
10.1016/0364-9229(79)90019-8
发表时间：
2016
期刊：
--
影响因子：
--
作者：
C. Freytag
通讯作者：
C. Freytag
DOI：
10.5860/choice.47-0244
发表时间：
2009-12
期刊：
Undergraduate Lecture Notes in Physics
影响因子：
--
作者：
Fulvio Melia
通讯作者：
Fulvio Melia
DOI：
10.1002/9783527618170
发表时间：
2014
期刊：
--
影响因子：
--
作者：
D. Kakkad
通讯作者：
D. Kakkad