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arXiv 2410.14404astro-ph.CO
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阿塔卡马宇宙学望远镜:星系团间桥梁的普查

The Atacama Cosmology Telescope: A census of bridges between galaxy clusters

G. Isopi, V. Capalbo, A. D. Hincks, L. Di Mascolo, E. Barbavara, E. S. Battistelli, J. R. Bond, W. Cui, W. R. Coulton, M. De Petris, M. Devlin, K. Dolag, J. Dun… 展开作者

G. Isopi, V. Capalbo, A. D. Hincks, L. Di Mascolo, E. Barbavara, E. S. Battistelli, J. R. Bond, W. Cui, W. R. Coulton, M. De Petris, M. Devlin, K. Dolag, J. Dunkley, D. Fabjan, A. Ferragamo, A. S. Gill, Y. Guan, M. Halpern, M. Hilton, J. P. Hughes, M. Lokken, J. van Marrewijk, K. Moodley, T. Mroczkowski, J. Orlowski-Scherer, E. Rasia, S. Santoni, C. Sifón, E. J. Wollack, G. Yepes

AI总结:

本文利用ACT的tSZ效应研究了星系团间的短纤维,通过叠加约100对星系团首次在中等红移下显著测得星系团间热气体信号,且结果与宇宙学模拟一致。

摘要:

根据CMB测量结果,重子物质约占宇宙质能密度的$5\\%$。这些重子中有很大一部分长期以来被称为“缺失”,它们存在于星系团外的低密度温热星系际介质(WHIM)中,勾勒出由大尺度暗物质纤维构成的“宇宙网”网络。多项研究已通过叠加方法以及在紧凑的大质量系统中观测单个纤维,探测到了这种星系团间的气体。在本文中,我们利用电离气体对CMB光的散射(即热Sunyaev-Zeldovich效应,tSZ效应),研究了由阿塔卡马宇宙学望远镜(ACT)探测到的大质量星系团($M_{500} \approx 3\times 10^{14} M_{\odot}$)之间连接的短纤维(< 10 Mpc)。第一部分工作是寻找适合进行高分辨率后续tSZ观测的候选体。我们识别出四对星系团,其星系团间信号高于噪声底(S/N $>$ 2),其中两对仅从ACT数据中就发现星系团间桥梁的统计显著性初步达到$>2σ$。在第二部分工作中,从相同的星系团样本出发,我们直接对约100对星系团进行叠加,观测到叠加星系团之间过剩的SZ信号为$y=(7.2^{+2.3}_{-2.5})\times 10^{-7}$,显著性为$3.3σ$。这是在中等红移($\langle z\rangle\approx 0.5$)下,对该质量范围内星系团间热气体的首次tSZ测量。我们将其与THE300和MAGNETICUM Pathfinder宇宙学模拟中具有相似红移和间距的模拟星系团对信号进行比较,发现广泛的一致性。此外,我们表明我们的测量结果与模拟中发现的纤维参数与嵌入晕质量之间的标度关系相一致。

英文摘要:

According to CMB measurements, baryonic matter constitutes about $5\%$ of the mass-energy density of the universe. A significant population of these baryons, for a long time referred to as `missing', resides in a low density, warm-hot intergalactic medium (WHIM) outside galaxy clusters, tracing the ``cosmic web'', a network of large scale dark matter filaments. Various studies have detected this inter-cluster gas, both by stacking and by observing individual filaments in compact, massive systems. In this paper, we study short filaments (< 10 Mpc) connecting massive clusters ($M_{500} \approx 3\times 10^{14} M_{\odot}$) detected by the Atacama Cosmology Telescope (ACT) using the scattering of CMB light off the ionised gas, a phenomenon known as the thermal Sunyaev-Zeldovich (tSZ) effect. The first part of this work is a search for suitable candidates for high resolution follow-up tSZ observations. We identify four cluster pairs with an intercluster signal above the noise floor (S/N $>$ 2), including two with a tentative $>2σ$ statistical significance for an intercluster bridge from the ACT data alone. In the second part of this work, starting from the same cluster sample, we directly stack on ${\sim}100$ cluster pairs and observe an excess SZ signal between the stacked clusters of $y=(7.2^{+2.3}_{-2.5})\times 10^{-7}$ with a significance of $3.3σ$. It is the first tSZ measurement of hot gas between clusters in this range of masses at moderate redshift ($\langle z\rangle\approx 0.5$). We compare this to the signal from simulated cluster pairs with similar redshifts and separations in the THE300 and MAGNETICUM Pathfinder cosmological simulations and find broad consistency. Additionally, we show that our measurement is consistent with scaling relations between filament parameters and mass of the embedded halos identified in simulations.

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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