文章基本信息

标题：First detection of a virial shock with SZ data: implication for the mass accretion rate of Abell 2319
本地全文：下载
作者：G. Hurier ; R. Adam ; U. Keshet 等
期刊名称：Astronomy & Astrophysics
印刷版ISSN：0004-6361
电子版ISSN：1432-0746
出版年度：2019
卷号：622
DOI：10.1051/0004-6361/201732468
语种：English
出版社：EDP Sciences
摘要：Shocks produced by the accretion of infalling gas in the outskirts of galaxy clusters are expected in the hierarchical structure formation scenario, as found in cosmological hydrodynamical simulations. Here, we report the detection of a shock front at a large radius in the pressure profile of the galaxy cluster A2319 at a significance of 8.6σ, usingPlanckthermal Sunyaev-Zel’dovich data. The shock is located at (2.93 ± 0.05) ×R500and is not dominated by any preferential radial direction. Using a parametric model of the pressure profile, we derive a lower limit on the Mach number of the infalling gas, ℳ > 3.25 at 95% confidence level. These results are consistent with expectations derived from hydrodynamical simulations. Finally, we use the shock location to constrain the accretion rate of A2319 toṀ≃ (1.4 ± 0.4) × 1014M⊙Gyr−1for a total mass ofM200 ≃ 1015 M⊙.
关键词：encosmic background radiationgalaxies: clusters: intracluster mediumgalaxies: clusters: individual: A2319