The Way to Quench:Galaxy Evolution in A2142  

作　　者：Cheng-Gong Qu Heng Yu Antonaldo Diaferio Jubee Sohn DengQi Liu 

机构地区：[1]Department of Astronomy,Beijing Normal University,Beijing 100875,China [2]Dipartimento di Fisica,Universitàdi Torino,Via P.Giuria 1,I-10125 Torino,Italy [3]Istituto Nazionale di Fisica Nucleare(INFN),Sezione di Torino,Via P.Giuria 1,I-10125 Torino,Italy [4]Astronomy Program,Department of Physics and Astronomy,Seoul National University,1 Gwanak-ro,Gwanak-gu,Seoul 08826,Republic of Korea [5]Smithsonian Astrophysical Observatory,60 Garden Street,Cambridge,MA 02138,USA

出　　处：《Research in Astronomy and Astrophysics》2023年第8期127-140,共14页天文和天体物理学研究（英文版）

基　　金：supported by Bureau of International Cooperation,Chinese Academy of Sciences GJHZ1864;partial support from the INFN grant InDark。

摘　　要：We show how the star formation activity of galaxies is progressively inhibited from the outer region to the center of the massive cluster A2142.From an extended spectroscopic redshift survey of 2239 galaxies covering a circular area of radius~11 Mpc from the cluster center,we extract a sample of 333 galaxies with known stellar mass,star formation rate,and spectral index D_(n)4000.We use the Blooming Tree algorithm to identify the substructures of the cluster and separate the galaxy sample into substructure galaxies,halo galaxies,and outskirt galaxies.The substructure and halo galaxies are cluster members,whereas the outskirt galaxies are only weakly gravitationally bound to the cluster.For the cluster members,the star formation rate per stellar mass decreases with decreasing distance R from the cluster center.Similarly,the spectral index D_(n)4000 increases with R,indicating an increasing average age of the stellar population in galaxies closer to the cluster center.In addition,star formation in substructure galaxies is generally more active than in halo galaxies and less active than in outskirt galaxies,proving that substructures tend to slow down the transition between field galaxies and cluster galaxies.We finally show that most actively star-forming galaxies are within the cluster infall region,whereas most galaxies in the central region are quiescent.

关 键 词：GALAXIES CLUSTERS individual(A2142)-galaxies star formation-galaxies EVOLUTION 

分 类 号：P152[天文地球—天文学]