The Significance of Thermally Pulsing Asymptotic Giant Branch Stars in Post-starburst Galaxies  

作　　者：Siqi Liu A-Li Luo 

机构地区：[1]CAS Key Laboratory of Optical Astronomy,National Astronomical Observatories,Beijing 100101,China [2]University of Chinese Academy of Sciences,Beijing 100049,China [3]College of Computer and Information Management&Institute for Astronomical Science,Dezhou University,Dezhou 253023,China

出　　处：《Research in Astronomy and Astrophysics》2023年第1期184-201,共18页天文和天体物理学研究（英文版）

基　　金：based on observation taken by the 3D-HST Treasury Program(GO 12177 and 12328)with NASA/ESA HST;operated by the Association of Universities for Research in Astronomy Inc.,under NASA contract NAS5-26555;supported by the National Natural Science Foundation of China(NSFC,Grant No.U1931209);the National Key R&D Program of China(No.2019YFA0405502)。

摘　　要：We measure the significance of thermally pulsing asymptotic giant branch(TP-AGB)stars via the spectral energy distributions(SEDs)of a sample of post-starburst(PSB)galaxies at z=0.2-0.7.Using ground-and space-based photometry from the 3D-HST catalog,as well as associated near-infrared(NIR)Hubble Space Telescope(HST)slitless grism spectroscopy,we evaluate the importance of TP-AGB stars in the SEDs of 177 PSB galaxies by fitting simple stellar populations with different levels of TP-AGB contributions.The grism spectra,despite their low resolution of R~100,enable the detection of molecular features specific to TP-AGB stars and thus improve constraints on their contribution.A majority(~70%)of galaxies in the PSB sample show features indicative of TPAGB stars,while the remainder does not and they are well fit by Bruzual&Charlot TP-AGB light models.Stacked spectra of sources classified to be the best fit by TP-AGB heavy/mild models reveal strong detections of NIR molecular features associated with TP-AGB stars.Additionally,we observe a tentative trend with redshift where more TP-AGB heavy galaxies are observed in the higher redshift PSB galaxy population.Finally,neglecting the contribution of TP-AGB stars can yield an over-prediction of stellar masses measured in the K-band ranging from 0.13-0.23 dex.

关 键 词：STARS AGB and post-AGB-galaxies stellar content-galaxies PECULIAR 

分 类 号：P152[天文地球—天文学]