The Clumpy Structure of Five Star-bursting Dwarf Galaxies in the MaNGA Survey  

作　　者：Mengting Ju Jun Yin Lei Hao Chenxu Liu Chao-Wei Tsai Junfeng Wang Zhengyi Shao Shuai Feng Yu Rong 

机构地区：[1]Key Laboratory for Research in Galaxies and Cosmology,Shanghai Astronomical Observatory,Chinese Academy of Sciences,Shanghai 200030,China [2]University of Chinese Academy of Sciences,Beijing 100049,China [3]Key Lab for Astrophysics,Shanghai 200034,China [4]South-Western Institute for Astronomy Research,Yunnan University,Kunming 650500,China [5]National Astronomical Observatories,Chinese Academy of Sciences,Beijing 100101,China [6]Institute for Frontiers in Astronomy and Astrophysics,Beijing Normal University,Beijing 102206,China [7]Department of Astronomy,Physics Building,Xiamen University,Xiamen,Fujian 361005,China [8]College of Physics,Hebei Normal University,Shijiazhuang 050024,China [9]Hebei Key Laboratory of Photophysics Research and Application,Shijiazhuang 050024,China [10]Department of Astronomy,University of Science and Technology of China,Hefei 230026,China

出　　处：《Research in Astronomy and Astrophysics》2024年第2期83-103,共21页天文和天体物理学研究（英文版）

基　　金：supported by National Key R&D Program of China(Nos.2019YFA0405501 and 2022YFF0503402);the National Natural Science Foundation of China(NSFC,Nos.12233005 and 12041302);support from the Natural Science Foundation of Shanghai(Project Number:22ZR1473000);the Program of Shanghai Academic Research Leader(No.22XD1404200);supports from the CAS Pioneer Hundred Talents Program;USTC Research Funds of the Double First-Class Initiative;the NSFC grant 12273037;the NSFC grants 12033004,12333003;support from the NSFC through grants 12273091 and U2031139。

摘　　要：The star-forming clumps in star-bursting dwarf galaxies provide valuable insights into understanding the evolution of dwarf galaxies.In this paper,we focus on five star-bursting dwarf galaxies featuring off-centered clumps in the Mapping Nearby Galaxies at Apache Point Observatory survey.Using the stellar population synthesis software Fitting Analysis using Differential evolution Optimization,we obtain the spatially resolved distribution of the star formation history,which allows us to construct the g-band images of the five galaxies at different ages.These images can help us to probe the evolution of the morphological structures of these galaxies.While images of a stellar population older than 1 Gyr are typically smooth,images of a stellar population younger than 1 Gyr reveal significant clumps,including multiple clumps which appear at different locations and even different ages.To study the evolutionary connections of these five galaxies to other dwarf galaxies before their star-forming clumps appear,we construct the images of the stellar populations older than three age nodes,and define them to be the images of the"host"galaxies.We find that the properties such as the central surface brightness and the effective radii of the hosts of the five galaxies are in between those of dwarf ellipticals(dEs)and dwarf irregulars(dIrrs),with two clearly more similar to dEs and one more similar to dIrrs.Among the five galaxies,8257-3704 is particularly interesting,as it shows a previous starburst event that is not quite visible from its gri image,but only visible from images of the stellar population at a few hundred million years.The star-forming clump associated with this event may have appeared at around 600 Myr ago and disappeared at around 40 Myr ago.

关 键 词：GALAXIES dwarf-galaxies evolution-galaxies formation-Galaxy STRUCTURE 

分 类 号：P152[天文地球—天文学]