2002/08/28 by Antonio Peimbert · 3 citations
Chemistry · Physics and Astronomy · #Analytical Chemistry (journal) #Astro and Planetary Science #Astronomy #Astrophysics #Astrophysics and Star Formation Studies #Atomic physics #Balmer series #Chemical composition #Chemistry #Doubly ionized oxygen #Electron temperature #Emission spectrum #Excited state #Ion #Line (geometry) #Nebula #Physics #Planetary nebula #Recombination #Spectral line #Stars #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1086/345793
published as Astrophys.J. 584 (2003) 735-750 · 37 pages, 2 figures, submitted to the Astrophysical Journal
arxiv created 2002/08/28 · openalex publication_date 2003/02/20 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Echelle spectrophotometry of the 30 Doradus nebula in the LMC is presented. The data consist of VLT UVES observations in the 3100-10350 Å range. The intensities of 366 emission lines have been measured, including 269 identified permitted lines of H 0 , He 0 , C 0 , C + , N + , N ++ , O 0 , O + , Ne 0 , Ne + , S + , S ++ , Si 0 , Si + , Si ++ , Ar + , and Mg + ; many of them are produced by recombination only while others mainly by fluorescence. Electron temperatures and densities have been determined using different line intensity ratios. The He + , C ++ , O + , and O ++ ionic abundances have been derived from recombination lines; these abundances are almost independent of the temperature structure of the nebula. Alternatively, abundances from collisionally excited lines have been derived for a large number of ions of different elements; these abundances depend strongly on the temperature structure. Accurate t 2 values have been derived from the Balmer continuum and by comparing the C ++ , O + , and O ++ ionic abundances obtained from collisionally excited and recombination lines. The chemical composition of 30 Doradus is compared with those of Galactic and extragalactic H II regions. The values of Δ Y /Δ O , Δ Y /Δ Z , and Y p are also discussed.