核心提示:欧洲航天局的“普朗克”探测器日前首次探测到连接两个星系团的热气体带。
欧洲航天局11月20日宣布,该机构的“普朗克”探测器日前首次探测到连接两个星系团的热气体带。
“普朗克”探测器日前探测发现,在距离地球约10亿光年的“埃布尔399”星系团和“埃布尔401”星系团之间有长达1000万光年的丝状热气体带。
欧航局初步推测,这些气体可能是由冷尘埃形成的纤维状物质和产生于星系团的气体混合而成。
“普朗克”探测器于2009年5月从法属圭亚那库鲁航天中心升空,主要任务是探测宇宙诞生的“余烬”——宇宙微波背景辐射,以帮助科学家研究早期宇宙形成和物质起源的奥秘。
据介绍,当宇宙微波背景辐射与星系团等巨大天体中的热气体相互作用时,就会导致能量分布产生变化,这个现象被称为“苏尼亚耶夫-泽尔多维奇效应”(简称“SZ”效应)。通过这一效应,“普朗克”探测器能探测到星系团间可能存在的丝状气体带。这次新发现便是“普朗克”首次利用“SZ”效应探测获得的。
新华网链接:http://news.xinhuanet.com/world/2012-11/21/c_113750793.htm
网易探索链接:http://discovery.163.com/12/1125/10/8H5B9AVD000125LI.html?from=index
早在2004年,南京师范大学的袁启荣教授等人就对Abell 399和Abell 401这一星系团对进行了研究,他们将文章发表在《Chinese Journal of Astronomy and Astrophysics》上,论文题目是:Merger Dynamics of the Pair of Galaxy Clusters A399 and A401,以下是文章摘要:
Abstract:Convincing evidence for a past interaction between the two rich clusters A399 and A401 was recently found in the X-ray imaging observations. We examine the structure and dynamics of this pair of galaxy clusters. A mixture-modeling algorithm was applied to obtain a robust partition into two clusters, which allowed us to discuss the virial mass and velocity distribution of each cluster. Assuming that these two clusters follow a linear orbit and they have once experienced a close encounter, we model the binary cluster as a two-body system. As a result, four gravitationally bound solutions are obtained. The recent X-ray observations seem to favor a scenario in which the two clusters with a true separation of 5.4h-1 Mpc are currently expanding at 583 km s-1 along a direction with a projection angle of 67.5°, and they will reach a maximum extent of 5.65 h-1 Mpc in about 1.0 h-1 Gyr.
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