ST ScI Preprint #1349
Respectfully dedicated to the memory of Karl Henize; astronaut, astronomer, seeker and finder of Wolf-Rayet stars.
We have completed a direct narrowband-broadband Schmidt plate survey of large areas of the southern Milky Way for new Wolf-Rayet (WR) stars as faint as 19th b magnitude. The 31 newly detected stars in the completed survey are amongst the reddest and/or most distant known in the Galaxy. We have obtained spectra of all candidate WR stars in the 22 fields stretching from l = 282o to l = 341o in longitude, and b = 3.5o in latitude, covering about 180 square degrees. We also observed two isolated Milky Way fields centered at l = 0o and l = 8o. Eighteen new WR stars are reported here for the first time. Combined with the 13 new WR stars we have already reported in Carina, our list of 31 new Galactic WR stars reaches 3-4 magnitudes fainter than previous surveys. Thirteen of our 18 new WR stars reported here are of subtype WN, while 5 are of subtype WC. We present and describe their spectra and subtypes, derive their distances, and discuss the significance of their locations along with all other WR stars in the Galaxy. Our new WR stars clearly demonstrate an increasing number ratio of WN to WC stars with increasing Galactocentric distance. We conclude with predictions of the total number of Galactic WR stars that should be discovered in future IR surveys.
1 Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218, USA
2 Département de Physique, Université de
Montréal, Montréal, QC Canada H3C 3J7
Observatoire de mont Mégantic
3 School of Physics, University of Sydney, Sydney, NSW 2006, Australia
4 Facultad de Cs. Astronómicas y Geofísicas, Universidad Nacional de La Plata Paseo del Bosque s/n, 1900 La Plata, Argentina
5 Member of Carrera del Investigador, CIC, Prov. Buenos Aires, Argentina.