2011/04/29 by Mónica Rodríguez, Gloria Delgado-Inglada
Physics and Astronomy · #Abundance (ecology) #Astronomy and Astrophysical Research #Astrophysics and Star Formation Studies #Cosmic dust #Electrical and Electromagnetic Research #Excited state #Homogeneous #Interstellar medium #Oxygen #Solar System #Spectral line #astro-ph.GA
paper · pdf · doi:10.1088/2041-8205/733/2/l50
5 pages, 1 figure, accepted for publication in ApJ Letters
arxiv created 2011/04/29 · openalex publication_date 2011/05/12 · arxiv updated 2015/05/28 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We present a homogeneous analysis of the oxygen abundance in five H ii regions and eight planetary nebulae (PNe) located at distances lower than 2 kpc and with available spectra of high quality. We find that both the collisionally excited lines (CELs) and recombination lines imply that the PNe are overabundant in oxygen by about 0.2 dex. An explanation that reconciles the oxygen abundances derived with CELs for H ii regions and PNe with the values found for B stars, the Sun, and the diffuse interstellar medium (ISM) requires the presence in H ii regions of an organic refractory dust component that is not present in PNe. This dust component has already been invoked to explain the depletion of oxygen in molecular clouds and in the diffuse ISM.