Determining the average SFR of K+A galaxies

We stack FIRST survey cutout images of 811 K+A galaxies to derive a mean 1.4 GHz radio image of our sample from which we measure a mean K+A flux density of 56 μJy. We carry out Monte Carlo simulations by randomly selecting radio-quiet white dwarfs to create 10,000 stacks equivalent to our K+A stack. From the measured fluxes of these stacks, we establish a 5σ detection limit of 43 μJy for stacked images. For the average redshift of our sample, we find an mean star formation rate of ~1.7 M_⊙ yr^-1. We split the sample by age and find a mean radio flux of 60 μJy, which corresponds to a star formation rate of 1.6 M_⊙ yr^-1, for galaxies with starburst ages less than 250 Myr.