arXivDaily arXiv每日学术速递 周一至周五更新
北美退伍军人节(Veterans Day),12 日无更新
arXiv 1002.4811astro-ph.CO
收藏

Abell 1689的朱雀观测:与大尺度结构相关的各向异性温度和熵分布

Suzaku Observation of Abell 1689: Anisotropic Temperature and Entropy Distributions Associated with the Large-Scale Structure

Madoka Kawaharada, Nobuhiro Okabe, Keiichi Umetsu, Motokazu Takizawa, Kyoko Matsushita, Yasushi Fukazawa, Takashi Hamana, Satoshi Miyazaki, Kazuhiro Nakazawa, Takaya Ohashi

摘要:

我们介绍了Abell 1689中的簇内介质(ICM)的朱雀观测结果,结合SDSS数据的补充分析以及Subaru/Suprime-Cam和HST/ACS观测的弱透镜和强透镜分析。在4.0 sigma显著性下检测到来自位力半径周围的ICM的微弱X射线发射。我们发现星系团外围的各向异性气体温度和熵分布与星系的大尺度结构有关。东北部(NE)郊区的高温和熵区与过密的对流结构有关。与低密度空隙环境接触的外围区域具有低的气体温度和熵,偏离流体静力平衡。这些结果表明,ICM的热化发生更快地沿导电结构比空隙区域。联合X射线和透镜分析表明,流体静力学质量是$\sim60-90%$的球面透镜,但相当于一个三轴晕质量误差内$0.6r_{2500} \simlt r \simlt 0.8r_{500}$,它是显着的偏见低$\simlt60%$内$0.4r_{2500}$,无论质量模型。$r_{500}$内的热气体压力最多为$\sim50$ --总压力的60%,以完全平衡球形透镜质量的重力,而$\sim30$ --维里半径周围的40%。虽然当考虑可能的晕三轴性时,这些构成了下限,但这些相对较小的热压力贡献将需要额外的压力源,例如体积和/或湍流运动。

英文摘要:

(Abridged) We present results of Suzaku observations of the intracluster medium (ICM) in Abell 1689, combined with complementary analysis of the SDSS data and weak and strong lensing analysis of Subaru/Suprime-Cam and HST/ACS observations. Faint X-ray emission from the ICM around the virial radius is detected at 4.0 sigma significance. We find anisotropic gas temperature and entropy distributions in cluster outskirts correlated with large-scale structure of galaxies. The high temperature and entropy region in the northeastern (NE) outskirts is connected to an overdense filamentary structure. The outskirt regions in contact with low density void environments have low gas temperatures and entropies, deviating from hydrostatic equilibrium. These results suggest that thermalization of the ICM occurs faster along the filamentary structures than the void regions. A joint X-ray and lensing analysis shows that the hydrostatic mass is $\sim60-90%$ of spherical lensing one but comparable to a triaxial halo mass within errors in $0.6r_{2500} \simlt r \simlt 0.8r_{500}$, and that it is significantly biased as low as $\simlt60%$ within $0.4r_{2500}$, irrespective of mass models. The thermal gas pressure within $r_{500}$ is, at most, $\sim50$--60% of the total pressure to balance fully the gravity of the spherical lensing mass, and $\sim30$--40% around the virial radius. Although these constitute lower limits when one considers the possible halo triaxiality, these small relative contributions of thermal pressure would require additional sources of pressure, such as bulk and/or turbulent motions.

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。

↑