J/other/RAA/24.I5007    SWAS Massive Star Formation Regions        (Wang+, 2024)

Molecular Oxygen Abundance in Galactic Massive Star Formation Regions Based on SWAS Observations. Wang B.-R., Li D., Goldsmith P.F., Wu J., Tsai C.-W., Quan D., Zhang X., Wang J., Melnick G.J., Li J.-Z., Fuller G.A., Xie J. <Res. Astron. Astrophys., 24, 095007 (2024)> =2024RAA....24i5007W 2024RAA....24i5007W (SIMBAD/NED BibCode)
ADC_Keywords: Star Forming Region ; Millimetric/submm sources ; Positional data Keywords: ISM: molecules - galaxies: abundances - ISM: lines and bands - Galaxy: abundances Abstract: 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 O2 spectrum based on this sample using the (SWAS) survey data (O2, 487.249GHz, N=3-1, J=3-2). No emission or absorption feature is seen around the supposed central velocity with a total integration time of ttotal=8.67x103hr and an rms noise per channel of 1.45mK. Assuming a kinetic temperature Tkin=30K, we derive the 3σ upper limit of the O2 column density to be 3.3x1015cm-2, close to the lowest values reported in Galactic massive star formation regions in previous studies. The corresponding O2 abundance upper limit is 6.7x10-8, 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 O2 abundance for Galactic massive star formation regions. This abundance is also lower than results reported in extragalactic sources. Description: We obtained an overall averaged O2 spectrum for a large sample of Galactic massive star formation regions based on the SWAS survey data. The observed positions in the massive star formation regions analyzed in this paper are listed in Table D1. File Summary: -------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------- ReadMe 80 . This file tabled1.dat 65 203 Massive Star Formation Regions Analyzed in the Paper -------------------------------------------------------------------------------- Byte-by-byte Description of file: tabled1.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 14 A14 --- Source Source name 15- 21 F7.2 h ttotal Overall total integration time (on+off) 23- 29 F7.2 arcsec oRA Relative right ascension 31- 37 F7.2 arcsec oDE Relative declination 39- 44 F6.2 deg RAdeg Reference right ascension (J2000) 46- 51 F6.2 deg DEdeg Reference declination (J2000) 53- 58 F6.2 deg GLON Galactic longitude 60- 65 F6.2 deg GLAT Galacitc latitude -------------------------------------------------------------------------------- History: From electronic version of the journal
(End) Patricia Vannier [CDS] 07-Aug-2025
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