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arXiv 2305.03082astro-ph.CO
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CHEX-MATE:约束星系团径向X射线表面亮度轮廓弥散的起源

CHEX-MATE: Constraining the origin of the scatter in galaxy cluster radial X-ray surface brightness profiles

I. Bartalucci, S. Molendi, E. Rasia, G. W. Pratt, M. Arnaud, M. Rossetti, F. Gastaldello, D. Eckert, M. Balboni, S. Borgani, H. Bourdin, M. G. Campitiello, S. D… 展开作者

I. Bartalucci, S. Molendi, E. Rasia, G. W. Pratt, M. Arnaud, M. Rossetti, F. Gastaldello, D. Eckert, M. Balboni, S. Borgani, H. Bourdin, M. G. Campitiello, S. De Grandi, M. De Petris, R. T. Duffy, S. Ettori, A. Ferragamo, M. Gaspari, R. Gavazzi, S. Ghizzardi, A. Iqbal, S. T. Kay, L. Lovisari, P. Mazzotta, B. J. Maughan, E. Pointecouteau, G. Riva, M. Sereno

AI总结:

本研究分析了118个星系团的X射线表面亮度轮廓,发现形态弛豫与受扰天体在0.4 R500处分叉,并首次利用模拟分解弥散成分,证实核心区高弥散源于气体真实分布差异且大于投影效应。

摘要:

我们研究了CHEX-MATE样本的空间分辨表面亮度轮廓的统计性质及弥散的起源,该样本由通过SZ效应选取的118个星系团组成。这些天体取自Planck SZ目录,覆盖了很宽的质量范围,M$_{500}=[2-15] \times 10^{14}$ M$_{\odot}$,以及红移范围,z=[0.05,0.6]。我们推导了表面亮度与发射量轮廓,并确定了完整样本的统计性质。我们发现在一个临界尺度,R$\sim 0.4 R_{500}$,以内,形态上弛豫的与受扰动的天体轮廓出现分叉。各子样本的中位数在$0.05\\,R_{500}$处相差约10倍。在应用适当的标度后,按质量和红移选取的子样本之间没有显著差异。我们将CHEX-MATE与从The Three Hundred宇宙学模拟套件中抽取的115个星系团样本进行了比较。我们发现模拟的发射量轮廓系统性地比观测轮廓更陡峭。首次利用模拟分解了导致轮廓间弥散的各个成分。我们考察了由逐个天体变化引起的弥散行为。我们发现,在$R<0.4R_{500}$处约110%的高弥散是由核心区气体分布的真实差异造成的。中间尺度,$R_{500} =[0.4-0.8]$,具有约0.56的最小弥散值,表明该区域星系团轮廓最接近自相似状态。更大尺度上由于气体复杂的空间分布,弥散有所增加。同样首次验证,在所有考虑的尺度上,由投影效应引起的弥散均小于由真实逐个天体变化引起的弥散。[节选]

英文摘要:

We investigate the statistical properties and the origin of the scatter within the spatially resolved surface brightness profiles of the CHEX-MATE sample, formed by 118 galaxy clusters selected via the SZ effect. These objects have been drawn from the Planck SZ catalogue and cover a wide range of masses, M$_{500}=[2-15] \times 10^{14} $M$_{\odot}$, and redshift, z=[0.05,0.6]. We derived the surface brightness and emission measure profiles and determined the statistical properties of the full sample. We found that there is a critical scale, R$\sim 0.4 R_{500}$, within which morphologically relaxed and disturbed object profiles diverge. The median of each sub-sample differs by a factor of $\sim 10$ at $0.05\,R_{500}$. There are no significant differences between mass- and redshift-selected sub-samples once proper scaling is applied. We compare CHEX-MATE with a sample of 115 clusters drawn from the The Three Hundred suite of cosmological simulations. We found that simulated emission measure profiles are systematically steeper than those of observations. For the first time, the simulations were used to break down the components causing the scatter between the profiles. We investigated the behaviour of the scatter due to object-by-object variation. We found that the high scatter, approximately 110%, at $R<0.4R_{500}$ is due to a genuine difference between the distribution of the gas in the core. The intermediate scale, $R_{500} =[0.4-0.8]$, is characterised by the minimum value of the scatter on the order of 0.56, indicating a region where cluster profiles are the closest to the self-similar regime. Larger scales are characterised by increasing scatter due to the complex spatial distribution of the gas. Also for the first time, we verify that the scatter due to projection effects is smaller than the scatter due to genuine object-by-object variation in all the considered scales. [abridged]

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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