Close Major-merger Pairs at z=0: Star-forming Galaxies with Pseudobulges  

作　　者：何川 徐聪 Ute Lisenfeld 戴昱 方陶陶 黄家声 王炜 余清正 Chuan He;Cong Xu;Ute Lisenfeld;Yu Sophia Dai;Taotao Fang;Jiasheng Huang;Wei Wang;Qingzheng Yu(Chinese Academy of Sciences South America Center for Astronomy,National Astronomical Observatories,Chinese Academy of Sciences,Beijing 100101,China;School of Astronomy and Space Sciences,University of Chinese Academy of Sciences,Beijing 100049,China;Departamento de Física Teórica y del Cosmos,Universidad de Granada,18071 Granada,Spain;Instituto Carlos I de Física Téorica y Computacional,Facultad de Ciencias,18071 Granada,Spain;Department of Astronomy,Xiamen University,Xiamen 361005,China;CAS Key Laboratory of Optical Astronomy,National Astronomical Observatories,Chinese Academy of Sciences,Beijing 100101,China)

机构地区：[1]Chinese Academy of Sciences South America Center for Astronomy,National Astronomical Observatories,Chinese Academy of Sciences,Beijing 100101,China [2]School of Astronomy and Space Sciences,University of Chinese Academy of Sciences,Beijing 100049,China [3]Departamento de Física Teórica y del Cosmos,Universidad de Granada,18071 Granada,Spain [4]Instituto Carlos I de Física Téorica y Computacional,Facultad de Ciencias,18071 Granada,Spain [5]Department of Astronomy,Xiamen University,Xiamen 361005,China [6]CAS Key Laboratory of Optical Astronomy,National Astronomical Observatories,Chinese Academy of Sciences,Beijing 100101,China

出　　处：《Research in Astronomy and Astrophysics》2024年第5期35-60,共26页天文和天体物理学研究（英文版）

基　　金：supported by the National Natural Science Foundation of China(NSFC)No.11873055 and No.11933003;sponsored(in part)by the Chinese Academy of Sciences(CAS)through a grant to the CAS South America Center for Astronomy(CASSACA);support from project PID2020-114414GB-100,financed by MCIN/AEI/10.13039/501100011033;the Junta de Andaluciaía(Spain)grant FQM108;support by the National Key R&D Program of China No.2017YFA0402600;the National Natural Science Foundation of China(NSFC)grant Nos.11890692,12133008,and 12221003;China Manned Space Project No.CMS-CSST2021-A04。

摘　　要：We present a study of star-forming galaxies (SFGs) with pseudobulges (bulges with Sérsic index n<2) in a loca close major-merger galaxy pair sample (H-KPAIR).With data from new aperture photometries in the optical and near-infrared bands (aperture size of 7 kpc) and from the literature,we find that the mean Age of central stellar populations in Spirals with pseudobulges is consistent with that of disky galaxies and is nearly constant against the bulge-to-total ratio (B/T).Paired Spirals have a slightly lower fraction of pure disk galaxies (B/T≤0.1) than their counterparts in the control sample.Compared to SFGs with classical bulges,those with pseudobulges have a higher (>2σ) mean of specific star formation rate (sSFR) enhancement (sSFR_(enh)=0.33±0.07 versus sSFR_(enh)=0.12±0.06) and broader scatter (by~1 dex).The eight SFGs that have the highest sSFR_(enh)in the sample all have pseudobulges.A majority (69%) of paired SFGs with strong enhancement (having sSFR more than5 times the median of the control galaxies) have pseudobulges.The Spitzer data show that the pseudobulges in these galaxies are tightly linked to nuclear/circum-nuclear starbursts.Pseudobulge SFGs in S+S and in S+E pairs have significantly (>3σ) different sSFR enhancement,with the means of sSFR_(enh)=0.45±0.08 and-0.04±0.11respectively.We find a decrease in the sSFR enhancements with the density of the environment for SFGs with pseudobulges.Since a high fraction (5/11) of pseudobulge SFGs in S+E pairs are in rich groups/clusters (loca density N_(1Mpc)≥7),the dense environment might be the cause for their low s SFR_(enh).

关 键 词：GALAXIES evolution-galaxies interactions-galaxies star formation-galaxies structure-galaxies bulges-galaxies PHOTOMETRY 

分 类 号：P15[天文地球—天文学]