A New Catalog of H II Regions in M31

H_alpha continuum subtracted images of M31. The original data is from Philip Massey, "A Survey of Local Group Galaxies Currently Forming Stars" , http://www2.lowell.edu/users/massey/lgsurvey/index.html . The original data contains 10 fields. We had to divide each field into smaller sub-regions to be able to run HII-phot (a code to identify and characterize HII regions (Thilker et.al., 2000AJ, 120, 3070) We had to mask all foreground stars. Residuals of H_alpha - R_band (after scaling) still made many false detections. Details of data reduction can be found at the original paper: A New Catalog of H II Regions in M31: Azimlu, M.; Marciniak, R.; Barmby, P., AJ 142, 139, http://adsabs.harvard.edu/abs/2011AJ...142..139A