A Near-infrared Survey of the Inner Galactic Plane for Wolf-Rayet Stars. II. Going Fainter: 71 More New W-R Stars
Abstract
We are continuing a J, K and narrowband imaging survey of 300 deg2 of the plane of the Galaxy, searching for new Wolf-Rayet (W-R) stars. Our survey spans 150° in Galactic longitude and reaches 1° above and below the Galactic plane. The survey has a useful limiting magnitude of K = 15 over most of the observed Galactic plane, and K = 14 (due to severe crowding) within a few degrees of the Galactic center. Thousands of emission-line candidates have been detected. In spectrographic follow-ups of 146 relatively bright W-R star candidates, we have re-examined 11 previously known WC and WN stars and discovered 71 new W-R stars, 17 of type WN and 54 of type WC. Our latest image analysis pipeline now picks out W-R stars with a 57% success rate. Star subtype assignments have been confirmed with the K-band spectra and distances approximated using the method of spectroscopic parallax. Some of the new W-R stars are among the most distant known in our Galaxy. The distribution of these new W-R stars is beginning to trace the locations of massive stars along the distant spiral arms of the Milky Way.
- Publication:
-
The Astronomical Journal
- Pub Date:
- June 2012
- DOI:
- 10.1088/0004-6256/143/6/149
- arXiv:
- arXiv:1106.2196
- Bibcode:
- 2012AJ....143..149S
- Keywords:
-
- Galaxy: disk;
- Galaxy: stellar content;
- infrared: stars;
- stars: emission-line;
- Be;
- stars: Wolf-Rayet;
- surveys;
- Astrophysics - Astrophysics of Galaxies
- E-Print:
- 48 pages, 25 figures, 8 Tables, Accepted by AJ 4-18-2012