东篱科研大数据发现系统（DRDS）

位置：成果数据库 > 期刊 > 期刊详情页

Low-ionization galaxies and evolution in a pilot survey up to z=1

ISSN号：1674-4527
期刊名称：《天文和天体物理学研究：英文版》
时间：0
分类：P152[天文地球—天文学] O562.4[理学—原子与分子物理;理学—物理]
作者机构：[1]LPTA, Universit6 Montpellier 2 - CNRS/IN2P3, 34095 Montpellier, France, edmond.giraud@ lpta. in2p3.fr, [2]Department of Astronomy, Nanjing University, Nanjing 210093, China, [3]European Southern Observatory,/klonso de Cbrdova 3107, Santiago, Chile, [4]Department of Astronomy and Astrophysics, R Universidad Catolica de Chile, Casilla 306,Santiago, Chile
相关基金：Supported by the National Natural Science Foundation of China（Grant Nos.10878010 10221001 and 10633040）; the National Basic Research Program（973 program No.2007CB815405）

作者： Edmond Giraud[1], Qiu-Sheng Gu[2], Jorge Melnick[3], Hernan Quintana[4], Fernando Selman[3], Ignacio Toledo[4], Paula Zelaya[4]

关键词：星系演化, 电离, 试验性, 发射线星系, 恒星形成, 光谱数据, 吸收线, 活动星系核, cosmology：observations—galaxies：evolution—large scale structures —evolution—RX J0054.0–2823

中文摘要：

我们从 10.75' 的一根铅笔横梁的现在的星群的分光镜的数据 ??蘴？？

英文摘要：

We present galactic spectroscopic data from a pencil beam of 10.75×7.5 centered on the X-ray cluster RXJ0054.0–2823 at z=0.29.We study the spectral evolution of galaxies from z=1 down to the cluster redshift in a magnitude-limited sample at R≤23,for which the statistical properties of the sample are well understood.We divide emission-line galaxies into star-forming galaxies,Low Ionization Nuclear Emission line Regions（LINERs） ,and Seyferts by using emission-line ratios of[OII],Hβ,and[OIII],and derive stellar fractions from population synthesis models. We focus our analysis on absorption and low-ionization galaxies.For absorption-line galaxies,we recover the well-known result that these galaxies have had no detectable evolution since z～0.6-0.7,but we also find that in the range z=0.65-1,at least 50% of the stars in bright absorption systems are younger than 2.5 Gyr.Faint absorption-line galaxies in the cluster at z=0.29 also had significant star formation during the previous 2-3 Gyr,but their brighter counterparts seem to be only composed of old stars.At z～0.8,our dynamically young cluster had a truncated red-sequence.This result seems to be consistent with a scenario where the final assembly of E/S0 took place at z1.In the volume-limited range 0.35≤z≤0.65,we find that 23% of the early-type galaxies have LINER-like spectra with Hβin absorption and have a significant component of A stars.The vast majority of LINERs in our sample have significant populations of young and intermediate-aged stars and are thus not related to AGNs,but to the population of‘retired galaxies’recently identified by Cid Fernandes et al.in the Sloan Digital Sky Survey（SDSS） .Early-type LINERs with various fractions of A stars and E＋A galaxies appear to play an important role in the formation of the red sequence.