CANDELS场中高红移大质量星系的形态结构性质
发布时间：2018-07-16 23:43
【摘要】：基于CANDELS(Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey)5个深场巡天的多波段测光数据和HST WFC3(Hubble Space Telescope Wide Field Camera 3)近红外(F125W和F160W)高分辨率观测图像,利用质量限(恒星质量M_*10~(10)M_⊙)选取了8002个红移分布在1z3范围内的星系样本,并对这些大质量星系的形态和结构性质进行了定量分析研究.通过星系形态的神经网络分类方法(Conv Nets),将样本中的星系划分为4类:椭球星系(SPHeroids,SPH)、早型盘星系(Early-Type Disks,ETD)、晚型盘星系(Late-Type Disks,LTD)和不规则星系(IRRegulars,IRR).结果发现星系的形态和结构随红移发生演化,在高红移宇宙星系主要表现出不规则形态,但到低红移处椭球和盘主导的哈勃星系形态序列已经形成.在相同红移区间内,不同类型星系的物理尺寸(r_e)中值从大到小的排序是IRR、LTD、ETD和SPH,而对应的Sersic指数(n)中值大小排序却相反.另外,不同类型星系的re与红移之间存在明显的演化关系,但这样的现象在平均轴比(b/a)和Sersic指数与红移的关系中并没有被发现.
[Abstract]:Based on the multiband photometry data of five deep field surveys and HST WFC3 (Hubble Space Telescope wide Field camera 3) Near-Infrared (F125W and F160W) high resolution observation images of CANDELS (Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey), Using the mass limit (stellar mass) of 10 ~ (10) M _ (298), we selected 8002 samples of galaxies with redshift in the range of 1z3, and quantitatively studied the morphological and structural properties of these massive galaxies. By means of Conv Nets, the galaxies in the sample are divided into four categories: the ellipsoid galaxy (SPH), the Early-Type disk galaxy (ETD), the Late-Type disk galaxy (LTD) and the irregular galaxy (IRR). The results show that the morphology and structure of the galaxies evolve with the redshift, and the main irregular morphology of the Gao Hong shift cosmic galaxies, but the ellipsoid and disk dominated Hubble galaxy shape sequence has been formed at the low redshift. In the same redshift region, the order of median values of physical dimensions from large to small for different types of galaxies is IRR / LTD / ETD and SPHs, whereas the corresponding order of (n) 's median value is opposite. In addition, there is an obvious evolutionary relationship between re and redshift in different types of galaxies, but this phenomenon is not found in the relationship between mean axis ratio (b / a) and Sersic index and redshift.
【作者单位】： 大理大学天文与科技史研究所;中国科学院星系与宇宙学重点实验室;中国科学技术大学天文学系;
【基金】：国家自然科学基金项目(11303002,11225315,11320101002) 中国科学院战略性先导科技专项(XDB09000000) 云南省应用基础研究计划项目(2014FB155)资助
【分类号】：P152
，
本文编号：2128080
[Abstract]:Based on the multiband photometry data of five deep field surveys and HST WFC3 (Hubble Space Telescope wide Field camera 3) Near-Infrared (F125W and F160W) high resolution observation images of CANDELS (Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey), Using the mass limit (stellar mass) of 10 ~ (10) M _ (298), we selected 8002 samples of galaxies with redshift in the range of 1z3, and quantitatively studied the morphological and structural properties of these massive galaxies. By means of Conv Nets, the galaxies in the sample are divided into four categories: the ellipsoid galaxy (SPH), the Early-Type disk galaxy (ETD), the Late-Type disk galaxy (LTD) and the irregular galaxy (IRR). The results show that the morphology and structure of the galaxies evolve with the redshift, and the main irregular morphology of the Gao Hong shift cosmic galaxies, but the ellipsoid and disk dominated Hubble galaxy shape sequence has been formed at the low redshift. In the same redshift region, the order of median values of physical dimensions from large to small for different types of galaxies is IRR / LTD / ETD and SPHs, whereas the corresponding order of (n) 's median value is opposite. In addition, there is an obvious evolutionary relationship between re and redshift in different types of galaxies, but this phenomenon is not found in the relationship between mean axis ratio (b / a) and Sersic index and redshift.
【作者单位】： 大理大学天文与科技史研究所;中国科学院星系与宇宙学重点实验室;中国科学技术大学天文学系;
【基金】：国家自然科学基金项目(11303002,11225315,11320101002) 中国科学院战略性先导科技专项(XDB09000000) 云南省应用基础研究计划项目(2014FB155)资助
【分类号】：P152
，
本文编号：2128080
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