红移z＜1卫星星系的恒星形成终止效率的研究

发布时间：2018-01-24 16:54

本文关键词： 星系演化卫星星系星系颜色恒星形成率　出处：《沈阳师范大学》2015年硕士论文　论文类型：学位论文

【摘要】：星系中恒星形成活动降低甚至终止的过程被称为星系的quenching过程。此过程是当前星系形成与演化的热点问题之一。目前的研究表明,影响星系quenching的因素可归纳为两类:一类是内部原因,如AGN的反馈、超新星爆发等原因把冷气体吹离、星系核球的增长);另外一类是外部原因,如环境影响,星系落入了更大的暗物质晕的过程中,受到激波加热或者引力能转化成热能加热或是暗物质晕的影响,星系受到周围星系或者暗物质的剥离作用。在标准星系形成与演化模型下,环境因素对卫星星系的quenching影响比中心星系更为重要。最近基于颜色分类标准的研究表明:从近邻宇宙一直追溯至红移z~0.8,卫星星系的恒星形成终止效率约为0.5。然而,由于受到星系中尘埃红化的影响,实际上一些基于颜色选择的“宁静星系”中的恒星形成活动可能并未终止。因此,本文利用DEEP2/AEGIS巡天的Gerke等人的中等红移(0.4z1)的星系群表,并结合SDSS巡天DR7版本的Yang等人的低红移(0.02z0.07)星系群表,重新研究了星系群环境对z1星系的quenching的影响。我们对比分析了基于颜色分类和恒星形成率(SFR)分类的结果。本文的主要结果如下:(1)在特定的恒星质量区间10.2 log(M/M)10.8???内,分别用颜色U-B和恒星形成率区分是否有恒星形成的星系,无论是哪种分类标准,卫星星系和中心星系中恒星形成终止的星系比例均随着红移的减小而增加,在相同的红移区间内,卫星星系中恒星形成终止的比例高于中心星系。(2)基于恒星形成率得到的恒星形成终止的星系比例比基于颜色得到的比例约30%,这导致卫星星系中基于恒星形成率分类得到的卫星星系quenching效率是前人基于颜色分类结果的约40%。本文的研究结果表明:在标准的星系形成与演化模型下,环境因素对大质量卫星星系的quenching影响比中心星系显著,但并不像近期基于颜色分类得到的结果那么重要。
[Abstract]:The process of decreasing or even terminating star formation in galaxies is called the quenching process of galaxies, which is one of the hot issues in the formation and evolution of galaxies. The factors affecting the quenching of galaxies can be divided into two categories: one is the internal reasons, such as the feedback from AGN, the explosion of supernova and so on, which blow away the cold gas, and the growth of the nuclear sphere of the galaxy; The other is external causes, such as environmental effects, in which galaxies fall into larger dark matter halos, affected by shock wave heating or gravitational energy conversion to heat or dark matter halo. Galaxies are separated by surrounding galaxies or dark matter. In the model of formation and evolution of standard galaxies. The influence of environmental factors on the quenching of satellite galaxies is more important than that of the central galaxies. Recent studies based on color classification criteria have shown that it can be traced back from the nearest universe to the redshift zl0. 8. The termination efficiency of star formation in satellite galaxies is about 0.5. However, it is affected by the redness of dust in the galaxies. In fact, star formation in some "quiet galaxies" based on color selection may not have ceased. In this paper, we make use of the galaxy cluster table of Gerke et al. (Gerke et al.) of the DEEP2/AEGIS survey. Combined with the SDSS Sky Survey DR7 version of Yang et al.'s low redshift 0. 02 z0. 07) Galactic Cluster Table. The effects of cluster environment on the quenching of Z1 galaxy are studied again. We compare and analyze the results of color classification and star formation rate classification. The main results of this paper are as follows: (1). 1) in a specific stellar mass range of 10.2 log / M / M 10.8? ? ? Within, color U-B and star formation rates are used to distinguish galaxies with or without star formation, regardless of classification criteria. The proportion of star formation terminating galaxies in satellite galaxies and central galaxies increases with the decrease of redshift, within the same redshift range. The proportion of star formation terminations in satellite galaxies is higher than that in central galaxies.) the proportion of star formation terminations based on star formation rate is about 30% compared with that based on color. As a result, the quenching efficiency of satellite galaxies based on star formation rate in satellite galaxies is about 40 percent higher than that of other satellite galaxies based on color classification. Under the standard galactic formation and evolution model. The influence of environmental factors on the quenching of large mass satellite galaxies is more significant than that of the central galaxies, but it is not as important as the recent results based on color classification.
【学位授予单位】：沈阳师范大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P152

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