HI in High Gas-phase Metallicity Dwarf Galaxy WISEA J230615.06+143927.9  

作　　者：Yan Guo C.Sengupta T.C.Scott P.Lagos Y.Luo 

机构地区：[1]Purple Mountain Observatory,Chinese Academy of Sciences,Nanjing 210023,China [2]School of Astronomy and Space Sciences,University of Science and Technology of China,Hefei 230026,China [3]Institute of Astrophysics and Space Sciences(IA Porto),Rua das Estrelas,4150-762,Porto,Portugal

出　　处：《Research in Astronomy and Astrophysics》2024年第1期292-299,共8页天文和天体物理学研究（英文版）

基　　金：support from the National Key Research and Development Program of China(2022SKA0130100);the National Natural Science Foundation of China (grant No. 12041306);supported by national funds through Fundacao para a Ciência e a Tecnologia (FCT);the Centro de Astrofísica da Universidade do Porto (CAUP)。

摘　　要：We present resolved Giant Metrewave Radio Telescope H I observations of the high gas-phase metallicity dwarf galaxy WISEA J230615.06+143927.9(z = 0.005)(hereafter J2306) and investigate whether it could be a Tidal Dwarf Galaxy(TDG) candidate. TDGs are observed to have higher metallicities than normal dwarfs. J2306 has an unusual combination of a blue g-r color of 0.23 mag, irregular optical morphology and high-metallicity(12 +log(O/H) = 8.68 ± 0.14), making it an interesting galaxy to study in more detail. We find J2306 to be an H I rich galaxy with a large extended, unperturbed rotating H I disk. Using our H I data we estimated its dynamical mass and found the galaxy to be dark matter(DM) dominated within its H I radius. The quantity of DM, inferred from its dynamical mass, appears to rule out J2306 as an evolved TDG. A wide area environment search reveals J2306 to be isolated from any larger galaxies which could have been the source of its high gas metallicity. Additionally, the H I morphology and kinematics of the galaxy show no indication of a recent merger to explain the high-metallicity.Further detailed optical spectroscopic observations of J2306 might provide an answer to how a seemingly ordinary irregular dwarf galaxy achieved such a high level of metal enrichment.

关 键 词：galaxies:abundances galaxies:dwarf galaxies:irregular radio lines:galaxies radio lines:ISM 

分 类 号：P148[天文地球—天体物理]