Spectroscopic studies of Wolf-Rayet stars. IV - Optical spectrophotometry of the emission lines in galactic and large Magellanic Cloud stars

Abstract

view Abstract Citations (178) References (36) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Spectroscopic Studies of Wolf-Rayet Stars. IV. Optical Spectrophotometry of the Emission Lines in Galactic and Large Magellanic Cloud Stars Conti, Peter S. ; Massey, Philip Abstract We present spectrophotometry of the leading emission-line features for nearly all the Wolf-Rayet stars in the Galaxy and in the Large Magellanic Cloud (LMC). These form the empirical basis of the normal relationships among the various lines. Emission lines have a wide range of strengths, but all lines in a given star are strong or weak together, aside from the well-understood ionization effects. We present the first extensive data of the N IV λ3480 feature in WN stars. This line persists to earlier types than does the singlet N IV λ4057 line, probably due to decreasing optical depth in the latter transition. Among those very few WN stars with anomalous lines, there are eight objects, mostly single stars, with inordinately strong C IV; we label them "WN/WC" and suggest that they have a "transition" composition between the WN and WC subclasses. We give quantitative descriptions of "early" (WNE; WCE) and "late" (WNL; WCL) types for the WN and WC classes, respectively. Among WC stars, the persistence of the C III λ4650 feature to the earliest subtypes (where C III λ5696 has already disappeared) suggests the importance of the contribution of C IV λ4658 to the blend, or an anomalous triplet-singlet behavior in the C III ions similar to that observed in N IV in the WN sequence. We compare the emission-line fluxes of He II λ4686 with the M_v_ for the WN stars of the LMC. Aside from the ionization effects, there is a nice correlation of these parameters since brighter stars have more continuum flux present at 4686 A. Although WCL stars have not been found in the LMC, the line strengths of the other W-R stars are very similar in that system and in our own Galaxy. Publication: The Astrophysical Journal Pub Date: February 1989 DOI: 10.1086/167101 Bibcode: 1989ApJ...337..251C Keywords: Emission Spectra; Magellanic Clouds; Optical Emission Spectroscopy; Stellar Spectrophotometry; Wolf-Rayet Stars; Abundance; Helium; Line Spectra; Statistics; Tables (Data); Astrophysics; GALAXIES: MAGELLANIC CLOUDS; SPECTROPHOTOMETRY; STARS: STELLAR STATISTICS; STARS: WOLF-RAYET full text sources ADS | data products SIMBAD (148) Related Materials (5) Part 1: 1983ApJ...268..228C Part 2: 1984ApJ...280..181T Part 3: 1986ApJ...300..379T Part 5: 1989ApJ...341..113C Part 6: 1990ApJ...354..359C