N II 5668-5712, a New Class of Spectral Features in Eta Carinae
Andrea Mehner(1), Kris Davidson(1), Gary J. Ferland(2)
(1) Department of Astronomy, University of Minnesota, Minneapolis, MN 55455
(2) Department of Physics & Astronomy, University of Kentucky, Lexington, KY 40506
We report on the N II 5668-5712 emission and absorption lines in the spectrum of eta Carinae. Spectral lines of the stellar wind regions can be classified into four physically distinct categories: 1) low-excitation emission such as H I and Fe II, 2) higher excitation He I features, 3) the N II lines discussed in this paper, and 4) He II emission. These categories have different combinations of radial velocity behavior, excitation processes, and dependences on the secondary star. The N II lines are the only known features that originate in “normal” undisturbed zones of the primary wind but depend primarily on the location of the hot secondary star. N II probably excludes some proposed models, such as those where He I lines originate in the secondary star’s wind or in an accretion disk.
Status: Manuscript has been accepted