Abstract

The Wolf-Rayet Content of M33

Philip Massey (Lowell Observatory)

Kathryn Neugent (Lowell Obs)

The Wolf-Rayet content of the Local Group provides an important tool for testing evolutionary models. We have recently completed a sensitive survey for WRs in NGC 6822, M31, and M33, and completed spectroscopic follow-up for the M33 candidates using the MMT. We were able to confirm 55 new WRs in M33, bringing to the total in that galaxy to 206, a value which we believe is now complete to about 5%. Our spectroscopy determined refined the spectral types of previously known WRs (one of which turns out to be a QSO!). The WC/WN ratios are accurately determined for the first time, and we compare the results to the Geneva models