N II λλ5668-5712: A New Class of Spectral Features in Eta Carinae
Abstract
We report on the N II λλ5668-5712 emission and absorption lines in the spectrum of η 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.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- August 2011
- DOI:
- 10.1088/0004-637X/737/2/70
- arXiv:
- arXiv:1104.1829
- Bibcode:
- 2011ApJ...737...70M
- Keywords:
-
- stars: emission-line;
- Be;
- stars: individual: eta Carinae;
- stars: variables: general;
- stars: winds;
- outflows;
- Astrophysics - Solar and Stellar Astrophysics
- E-Print:
- 4 figures, 1 table