星系团A2319的多色测光研究
发布时间：2019-02-26 21:40
【摘要】：作为宇宙中最大的引力束缚系统,星系团通常位于宇宙纤维状结构的节点上,是宇宙大尺度结构的示踪物,也是研究星系之间相互作用和各种演化过程的环境效应的重要实验室。 本文主要利用BATC(Beijing-Arizona-Taiwan-Connecticut)的多色测光数据,对星系团A2319(zc=0.0557)进行了初步的测光研究。BATC多色测光系统利用国家天文台兴隆观测基地的60/90厘米施密特望远镜,配备了15个中带(a-k,m-P)滤光片,波长覆盖范围从3000A到10000A。在58’×58’视场中,NASA/IPAC Extragalactic Database (NED)已经收录了140个已知光谱红移的星系数据,其中137个星系是A2319的成员星系(样本Ⅰ)。样本Ⅰ的空间投影分布与局域速度分布均支持A2319是个动力学活跃的星系团,这也与X射线的观测相吻合。K-test表明在A2319中心区域存在2个子结构,而且空间投影分布有东北-西南方向的拉伸。根据位力定理,估算了A2319主团和子团的质量,二者在投影角α处于22°到82°范围内是引力束缚的。 利用BATC多色测光数据,我们通过双色图和测光红移估计来挑选A2319中暗成员星系的候选体。A2319处于低银纬(～13°)天区,视宁度较差的BATC图像具有严重的前景星场污染。为了排除暗成员星系候选体中由于前景星场污染造成的伪源,我们利用美国Steward大学的Bok2.3m望远镜的视宁度良好的U波段图像,最终挑选出233个暗成员星系。与样本Ⅰ合并得到了一个包括370个成员星系的大样本(样本Ⅱ)。基于样本Ⅱ,A2319成员星系的空间分布表现出更明显的动力学子结构。局域速度分布的统计检验显示,星系团A2319西北(NW)方向10’处存在显著的子结构,与前人的研究结果相符。同时,在团中心西北方向大约22’处还发现一个子团。 此外,基于Sloan光谱巡天数据提供的242个成员星系的光谱,利用星族合成软件STARLIGHT获得了这些成员星系的星族成份和恒星形成历史,研究了这些星系的恒星形成性质(如特征星族年龄、金属丰度、恒星质量和恒星形成率等)随星系面密度的变化规律。研究结果表明：处于环境密度较高的团中心区域的星系具有较高的星族年龄和金属丰度,其比恒星形成率较低,而在最近24.5Myr内的恒星形成活动受到抑制。最后,我们还确认了星系金属丰度、比恒星形成率与恒星质量的相关性。该部分研究是一年前通过团队合作完成,论文已经被《天文学报》接收,即将发表。
[Abstract]:As the largest gravitational binding system in the universe, the cluster of galaxies is usually located at the node of the cosmic fibrous structure and is a tracer of the large-scale structure of the universe. It is also an important laboratory for the study of intergalactic interactions and the environmental effects of various evolutionary processes. In this paper, we mainly use the multicolor photometric data of BATC (Beijing-Arizona-Taiwan-Connecticut), A preliminary photometric study of cluster A2319 (zc=0.0557) has been carried out. The BATC multicolor photometric system uses the 60-90 cm Schmidt telescope at the National Observatory's Xinglong observation Base and is equipped with 15 medium-band (aqk, mp) filters. The BATC multicolor photometric system uses the 60-90 cm Schmidt telescope at the National Observatory's Xinglong Observatory. Wavelength coverage from 3000A to 10000A In the 58'脳 58 'field of view, NASA/IPAC Extragalactic Database (NED) has recorded 140 known spectral redshifts of galaxies, of which 137 are member galaxies of A2319 (sample I). Both the spatial projection distribution and the local velocity distribution of sample 鈪，
本文编号：2431170
[Abstract]:As the largest gravitational binding system in the universe, the cluster of galaxies is usually located at the node of the cosmic fibrous structure and is a tracer of the large-scale structure of the universe. It is also an important laboratory for the study of intergalactic interactions and the environmental effects of various evolutionary processes. In this paper, we mainly use the multicolor photometric data of BATC (Beijing-Arizona-Taiwan-Connecticut), A preliminary photometric study of cluster A2319 (zc=0.0557) has been carried out. The BATC multicolor photometric system uses the 60-90 cm Schmidt telescope at the National Observatory's Xinglong observation Base and is equipped with 15 medium-band (aqk, mp) filters. The BATC multicolor photometric system uses the 60-90 cm Schmidt telescope at the National Observatory's Xinglong Observatory. Wavelength coverage from 3000A to 10000A In the 58'脳 58 'field of view, NASA/IPAC Extragalactic Database (NED) has recorded 140 known spectral redshifts of galaxies, of which 137 are member galaxies of A2319 (sample I). Both the spatial projection distribution and the local velocity distribution of sample 鈪，
本文编号：2431170
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