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Title: A Survey for C ii Emission-line Stars in the Large Magellanic Cloud. II. Final Results and the Origin of C ii Emission in [WC] Spectra
Abstract

We present the final results of an imaging and spectroscopic search for stars in the Large Magellanic Cloud (LMC) with Ciiλλ7231, 7236 emission lines. The goal is to identify and study [WC11] stars, the coolest of the low-mass Wolf–Rayet sequence, and a subset of central stars of planetary nebulae where the Ciilines are known to be especially prominent. A recent serendipitous discovery of an LMC [WC11] raised the possibility that these objects, although difficult to identify, might in fact be more common than previously believed. Several new members of this rare class have been found in this survey. It now seems clear, however, that a significant number of these stars are not hiding among the general [WC] population. We point out that the Ciidoublet intensity ratio observed in our spectra proves to neatly divide the objects into two distinct groups, with the Ciiemission likely originating from either the stellar wind or a surrounding nebula. The physics of the Ciiemission mechanism correctly explains this bifurcation. Spectral subtypes are suggested for most of the objects. The numerous spectroscopic clues now available for these objects should facilitate future detailed modeling.

 
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NSF-PAR ID:
10391482
Author(s) / Creator(s):
; ; ; ;
Publisher / Repository:
DOI PREFIX: 10.3847
Date Published:
Journal Name:
The Astrophysical Journal
Volume:
942
Issue:
2
ISSN:
0004-637X
Format(s):
Medium: X Size: Article No. 85
Size(s):
Article No. 85
Sponsoring Org:
National Science Foundation
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