(a, left) Histogram of SNR diameter for all candidates and for those with spectra. (b, right) Histogram of galactocentric distance (GCD) for all candidates and for those with spectra. Our sample is representative of the entire ensemble of sizes and distances, except for the smallest and largest GCDs. As noted in the text, we targeted few objects in the nuclear region of M83 because of confusion and the difficulty of background subtraction, and none in the very outermost regions because this would have been an inefficient use of the GMOS.