Molecular Oxygen Abundance in Galactic Massive Star Formation Regions Based on SWAS Observations  

作　　者：Bing-Ru Wang Di Li Paul F.Goldsmith Jingwen Wu Chao-Wei Tsai Donghui Quan Xia Zhang Junzhi Wang Gary J.Melnick Jin-Zeng Li Gary A.Fuller Jinjin Xie 

机构地区：[1]National Astronomical Observatories,Chinese Academy of Sciences,Beijing 100101,China [2]Tsinghua University,Beijing 100084,China [3]University of Chinese Academy of Sciences,Beijing 100049,China [4]Research Center for Astronomical Computing,Zhejiang Laboratory,Hangzhou 311100,China [5]Jet Propulsion Laboratory,California Institute of Technology,Pasadena,CA 91109,USA [6]Institute for Frontiers in Astronomy and Astrophysics,Beijing Normal University,Beijing 102206,China [7]Xinjiang Astronomical Observatory,Chinese Academy of Sciences,Urumqi 830011,China [8]Guangxi Key Laboratory for Relativistic Astrophysics,School of Physical Science and Technology,Guangxi University,Nanning 530004,China [9]Center for Astrophysics,Harvard&Smithsonian,60 Garden Street,MS 66,Cambridge,MA 02138,USA [10]Jodrell Bank Center for Astrophysics,Department of Physics&Astronomy,University of Manchester,Oxford Road,Manchester,M139PL,UK [11]I.Physikalisches Institut,University of Cologne,Zülpicher Str.77,50937 Köln,Germany

出　　处：《Research in Astronomy and Astrophysics》2024年第9期83-98,共16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,Grant Nos.11988101 and12041302);the International Partnership Program of the Chinese Academy of Sciences(grant No.114A11KYSB20210010);National Key R&D Program of China No.2023YFA1608004;operated by the California Institute of Technology under a contract with the National Aeronautics and Space Administration(80NM0018D0004);the support of the Tianchi Talent Program of Xinjiang Uygur Autonomous Region;the Collaborative Research Center 1601(SFB 1601 sub-project A2);funded by the Deutsche Forschungsgemeinschaft—500700252;support from the University of Cologne and its Global Faculty program。

摘　　要：Molecular oxygen abundance is a key parameter in understanding the chemical network of the interstellar medium.We estimate the molecular oxygen column density and abundance for a sample of Galactic massive star formation regions based on observations from the Submillimiter Wave Astronomy Satellite(SWAS)survey.We obtained an averaged O_(2)spectrum based on this sample using the(SWAS)survey data(O_(2),487.249 GHz,N=3-1,J=3-2).No emission or absorption feature is seen around the supposed central velocity with a total integration time of t_(total)=8.67×10^(3)hr and an rms noise per channel of 1.45 m K.Assuming a kinetic temperature T_(kin)=30 K,we derive the 3σupper limit of the O_(2)column density to be 3.3×10^(15)cm^(-2),close to the lowest values reported in Galactic massive star formation regions in previous studies.The corresponding O_(2)abundance upper limit is6.7×10^(-8),lower than all previous results based on SWAS observations and is close to the lowest reported value in massive star formation regions.On a galactic scale,our statistical results confirm a generally low O_(2)abundance for Galactic massive star formation regions.This abundance is also lower than results reported in extragalactic sources.

关 键 词：ISM:molecules galaxies:abundances ISM:lines and bands Galaxy:abundances 

分 类 号：P156[天文地球—天文学] P111.44