Open AccessSearching for hidden Wolf–Rayet stars in the Galactic plane – 15 new Wolf–Rayet stars
Author(s) -
Hadfield L. J.,
Van Dyk S. D.,
Morris P. W.,
Smith J. D.,
Marston A. P.,
Peterson D. E.
Publication year - 2007
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1111/j.1365-2966.2007.11424.x
Subject(s) - physics , wolf–rayet star , astrophysics , stars , galactic plane , galaxy , astronomy , supergiant , sky , o type star , k type main sequence star , t tauri star
We report the discovery of 15 previously unknown Wolf–Rayet (WR) stars found as part of an infrared (IR) broad‐band study of candidate WR stars in the Galaxy. We have derived an empirically based selection algorithm which has selected ∼5000 WR candidate stars located within the Galactic plane drawn from the Galactic Legacy Infrared Mid‐Plane Survey Extraordinaire (mid‐IR) and Two‐Micron All‐Sky Survey (near‐IR) catalogues. Spectroscopic follow‐up of 184 of these reveals 11 nitrogen‐rich (WN) and four carbon‐rich (WC) WR stars. Early WC subtypes are absent from our sample and none shows evidence for circumstellar dust emission. Of the candidates which are not WR stars, ∼120 displayed hydrogen emission‐line features in their spectra. Spectral features suggest that the majority of these are in fact B supergiants/hypergiants, ∼40 of these are identified Be/B[e] candidates. Here, we present the optical spectra for six of the newly detected WR stars, and the near‐IR spectra for the remaining nine of our sample. With a WR yield rate of ∼7 per cent and a massive star detection rate of ∼65 per cent, initial results suggest that this method is one of the most successful means for locating evolved, massive stars in the Galaxy.