首页    期刊浏览 2024年09月06日 星期五
登录注册

文章基本信息

  • 标题:The XMM Cluster Outskirts Project (X-COP): Thermodynamic properties of the intracluster medium out to R 200 in Abell 2319
  • 本地全文:下载
  • 作者:V. Ghirardini ; S. Ettori ; D. Eckert
  • 期刊名称:Astronomy & Astrophysics
  • 印刷版ISSN:0004-6361
  • 电子版ISSN:1432-0746
  • 出版年度:2018
  • 卷号:614
  • DOI:10.1051/0004-6361/201731748
  • 语种:English
  • 出版社:EDP Sciences
  • 摘要:Aims.We present the joint analysis of the X-ray and Sunyaev–Zel’dovich (SZ) signals in Abell 2319, the galaxy cluster with the highest signal-to-noise ratio in SZPlanckmaps and that has been surveyed within ourXMM-NewtonCluster Outskirts Project (X-COP), a very large program which aims to grasp the physical condition in 12 local (z< 0.1) and massive (M200> 3 × 1014 M⊙) galaxy clusters out toR200and beyond.Methods.We recover the profiles of the thermodynamic properties by the geometrical deprojection of the X-ray surface brightness, of the SZ Comptonization parameter, and accurate and robust spectroscopic measurements of the gas temperature out to 3.2 Mpc (1.6R200), 4 Mpc (2R200), and 1.6 Mpc (0.8R200), respectively. We resolve the clumpiness of the gas density to be below 20% over the entire observed volume. We also demonstrate that most of this clumpiness originates from the ongoing merger and can be associated with large-scale inhomogeneities (the “residual” clumpiness). We estimate the total mass through the hydrostatic equilibrium equation. This analysis is done both in azimuthally averaged radial bins and in eight independent angular sectors, enabling us to study in detail the azimuthal variance of the recovered properties.Results.Given the exquisite quality of the X-ray and SZ datasets, their radial extension, and their complementarity, we constrain atR200the total hydrostatic mass, modelled with a Navarro–Frenk–White profile at very high precision (M200= 10.7 ± 0.5stat.± 0.9syst.× 1014 M⊙). We identify the ongoing merger and how it is affecting differently the gas properties in the resolved azimuthal sectors. We have several indications that the merger has injected a high level of non-thermal pressure in this system: the clumping free density profile is above the average profile obtained by stacking Rosat/PSPC observations; the gas mass fraction recovered using our hydrostatic mass profile exceeds the expected cosmic gas fraction beyondR500; the pressure profile is flatter than the fit obtained by the Planck Collaboration; the entropy profile is flatter than the mean profile predicted from non-radiative simulations; the analysis in azimuthal sectors has revealed that these deviations occur in a preferred region of the cluster. All these tensions are resolved by requiring a relative support of about 40% from non-thermal to the total pressure atR200.
  • 关键词:Key wordsengalaxies: clusters: generalgalaxies: clusters: intracluster mediumX-rays: galaxies: clustersintergalactic medium
国家哲学社会科学文献中心版权所有