arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1604.07413astro-ph.GAastro-ph.CO
收藏

对星系恒星质量函数演化的限制I:恒星形成、合并和恒星剥离的作用

Constraints on the Evolution of the Galaxy Stellar Mass Function I: Role of Star Formation, Mergers and Stellar Stripping

E. Contini, X. Kang, A. D. Romeo, Q. Xia

摘要:

我们研究了观测到的恒星形成率-恒星质量(SFR- $M_*$)关系和恒星质量函数(SMF)演化之间的联系,通过一个耦合到从N体模拟中提取的并合树的Subhalo AbnormalMatching技术.我们的方法,它考虑了星系合并和恒星剥离,是强迫模型匹配观测到的SMF在红移$z>2$,并让它演变到现在的时间根据观测到的(SFR- $M_*$)关系。在这项研究中,我们使用两个不同的SMF和两个SFR- $M_*$关系:一个简单的幂律和一个关系与质量相关的斜率。我们的分析表明,SMF的演化更符合SFR- $M_*$关系与质量依赖的斜率,与其他模型的星系演化和最近的观测预测一致。为了充分和现实地描述SMF的演变,合并和恒星剥离必须考虑,我们发现,这两个几乎相同的影响SMF的大规模结束的演变。考虑到观测数据的系统不确定性,通过考虑恒星剥离得到的SMF的高质量端与斯隆数字巡天(SDSS)最近的观测数据吻合得很好。在$\log M_* < 11.2$,我们的预测在z=0.1接近\citet{li-white09}数据,但高质量端($\log M_* > 11.2$)是在更好的协议与\citet{dsouza15}数据,占更大的星系。

英文摘要:

We study the connection between the observed star formation rate-stellar mass (SFR-$M_*$) relation and the evolution of the stellar mass function (SMF) by means of a Subhalo Abundance Matching technique coupled to merger trees extracted from a N-body simulation. Our approach, which considers both galaxy mergers and stellar stripping, is to force the model to match the observed SMF at redshift $z>2$, and let it evolve down to the present time according to the observed (SFR-$M_*$) relation. In this study, we use two different sets of SMFs and two SFR-$M_*$ relations: a simple power law and a relation with a mass-dependent slope. Our analysis shows that the evolution of the SMF is more consistent with a SFR-$M_*$ relation with a mass-dependent slope, in agreement with predictions from other models of galaxy evolution and recent observations. In order to fully and realistically describe the evolution of the SMF, both mergers and stellar stripping must be considered, and we find that both have almost equal effects on the evolution of SMF at the massive end. Taking into account the systematic uncertainties in the observed data, the high-mass end of the SMF obtained by considering stellar stripping results in good agreement with recent observational data from the Sloan Digital Sky Survey (SDSS). At $\log M_* < 11.2$, our prediction at z=0.1 is close to \citet{li-white09} data, but the high-mass end ($\log M_* > 11.2$) is in better agreement with \citet{dsouza15} data which account for more massive galaxies.

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。

↑