Identification of the 4486 , 4504 Å emission lines in O - type spectra
نویسنده
چکیده
Inspired by an appeal to the community fromWalborn (these proceedings) we decided to solve the long-standing problem concerning the nature of the 4486, 4504Å emission lines, which are frequently observed in O-type spectra and which are particularly prominent in supergiants. We claim that these lines emerge from sulfur, namely by deexcitation of a highly excited S IV doublet state. We prove this by an exploratory NLTE calculation with a detailed model atom.
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