arXivDaily arXiv每日学术速递 周一至周五更新
稍安勿躁,官方尚未更新
arXiv 0707.4342astro-ph
收藏

AWM 7星系团的朱雀观测:温度、绝对辐射和整体运动

Suzaku Observations of AWM 7 Cluster of Galaxies: Temperature, Abundance and Bulk Motions

Kosuke Sato, Kyoko Matsushita, Yoshitaka Ishisaki, Noriko Y. Yamasaki, Manabu Ishida, Shin Sasaki, Takaya Ohashi

摘要:

我们对星系团AWM 7进行了3次观测,分别是中心区域和20 '东偏和20'西偏区域。温度和丰度剖面的测量范围为27 '~ 570 /h_70 kpc,对应于~0.35 r_180。团簇内介质的温度从中心的3.8keV略微降低到~ 0.35r180区域的3.4keV,表明团簇内介质的温度分布比附近的其他团簇更为平坦。在我们的观测中,Si与Fe的比例几乎是恒定的,而Mg与Fe的比例随着半径的增加而增加。西部地区的O/Fe比值随半径的增大而增大,东部地区的O/Fe比值随半径的增大而减小,但误差较大。这些特征表明,II型超新星的产物(O和Mg)和Ia型超新星的产物(Si和Fe)之间的富集过程是显着不同的。我们还研究了类He Fe-Ka线中心能量的位置移动,以寻找ICM可能的旋转。视线速度差的90%上限被推导为v ~ 2000 km/s,这表明AWM 7的椭圆率是由最近沿着大尺度暗条的气体定向下降引起的。

英文摘要:

We carried out 3 observations of the cluster of galaxies AWM 7, for the central region and 20'-east and 20'-west offset regions, with Suzaku. Temperature and abundance profiles are measured out to 27'~ 570 /h_70 kpc, which corresponded to ~0.35 r_180. The temperature of the intra-cluster medium (ICM) slightly decreases from 3.8 keV at the center to 3.4 keV in ~0.35 r_180 region, indicating a flatter profile than those in other nearby clusters. Abundance ratio of Si to Fe is almost constant in our observation, while Mg to Fe ratio increases with radius from the cluster center. O to Fe ratio in the west region shows increase with radius, while that in the east region is almost flat, though the errors are relatively large. These features suggest that the enrichment process is significantly different between products of type II supernovae (O and Mg) and those by type Ia supernovae (Si and Fe). We also examined positional shift of the central energy of He-like Fe-Ka line, in search of possible rotation of the ICM. The 90% upper limit for the line-of-sight velocity difference was derived to be v ~ 2000 km/s, suggesting that the ellipticity of AWM 7 is rather caused by a recent directional infall of the gas along the large-scale filament.

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。

↑