HII shells surrounding Wolf-Rayet stars in M31

We present the results of an ongoing investigation to provide a detailed vi ew of the processes by which massive stars shape the surrounding interstell ar medium (ISM), from parsec to kiloparsec scales. In this paper, we focus on studying the environments of Wolf-Rayet (W-R) stars in M31 to find evide nce for W-R wind-ISM interactions, through imaging ionized hydrogen nebulae surrounding these stars. We have conducted a systematic survey for H II sh ells surrounding 48 of the 49 known W-R stars in M31. There are 17 W-R star s surrounded by single shells, or shell fragments, seven stars surrounded b y concentric, limb-brightened shells, 20 stars where there is no clear phys ical association of the star with nearby H alpha emission, and four stars t hat lack nearby H alpha emission. Of the 17 + 7 shells above, there are 12 that contain one or two massive stars (including a W-R star) and that are l ess than or equal to 40 pc in radius. These 12 shells may be classical W-R ejecta or windblown shells. Further, there may be excess H alpha point-sour ce emission associated with one of the 12 W-R stars surrounded by putative ejecta or windblown shells. There is also evidence for excess point-source emission associated with 11 other W-R stars. The excess emission may arise from unresolved circumstellar shells or within the extended outer envelopes of the stars themselves. In a few cases, we find clear morphological evide nce for W-R shells interacting with each other. In several H alpha images, we see W-R winds disrupting, or punching through, the walls of limb-brighte ned H II shells.