CANDELS场中z~2星系的形态结构研究
首发时间:2016-05-16
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(Hubble Space Telescope)近红外(F160W)高分辨率观测图像,利用BzK(${ m B-z}$和${ m z-K}$)双色图技术选取了1586个恒星形成星系(star forminggalaxies, sBzKs)和271个被动演化星系(passively evolving galaxies, pBzKs),它们对应的红移平均值分别为$1.80pm0.49$和$1.73pm0.38$,并对这些大质量(恒星质量$M_{st}gtrsim10^{10}~M_{odot}$)星系的形态结构特征进行了研究。在sBzKs样本中, 静止光学波段形态呈现出椭圆、盘状和不规则结构特征的源所占比例依次为15%、18%和67%, 而对于pBzKs来说, 对应的比例分别是44%、37%和19%。另外,高红移sBzKs和pBzKs的有效半径($r_{ m e}$)中值分别对应$2.52pm1.37$ kpc和$1.90pm1.02$ kpc, 明显小于近邻同类型相似质量的星系,表明随着红移减小,星系尺寸逐渐变大。
关键词: 天体物理 星系演化 星系形态 星系结构 高红移星系
For information in English, please click here
Morphology and structure of z~2 Galaxies in the CANDELS Field
Abstract:Using the multi-band photometry data of all five CANDELS (Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey) fields and the high-resolution HST WFC3 (Hubble Space Telescope Wide Field Camera 3) near-infrared imaging (F160W), we present a quantitative study of morphology and structure ofBzK-selected (two-color ${ m B-z}$ vs. ${ m z-K}$ diagram) Galaxies. The sample of 1857 BzKs including 1586 star-forming galaxies (sBzKs) and 271 passively evolving galaxies (pBzKs). The mean redshifts of sBzKs and pBzKs are $1.80pm0.49$ and $1.73pm0.38$, respectively. For the rest-frame optical morphologies of sBzKs (pBzKs), the fractionsof ellipticals, disks, and irregular galaxies correspond to 15% (44%), 18%(37%), and 67%(19%), respectively.Moreover, the median effective radii of sBzKs and pBzKs, corresponding to $2.52pm1.37$ kpc and $1.90pm1.02$ kpc, respectively. The findings show that the sizes of pBzKs (sBzKs) are smaller than that of present-day early-type (late-type) galaxies with analogous stellar mass at rest-frame optical wavelength, indicatingthe evolution of high-redshift massive galaxy size with redshift.
Keywords: astrophysics galaxy evolution galaxy morphology galaxy structure high redshift galaxies
基金:
论文图表:
引用
No.4687619114497814****
同行评议
共计0人参与
勘误表
CANDELS场中z~2星系的形态结构研究
评论
全部评论0/1000