Determining the average SFR of K+A galaxies
Nielsen, Danielle M. ( Dept. of Astronomy, University of Wisconsin ─ Madison 475 N. Charter Street, Madison, WI 53706, USA ); de Propris, Roberto ( Cerro Tololo Inter-American Observatory, La Serena, Chile ); Ridgway, Susan E. ( National Optical Astronomy Observatory, 950 N. Cherry Avenue, Tucson, AZ 85719, USA ); Goto, Tomotsugu ( Subaru Telescope, Hilo, HI, USA ) show affiliations
The Spectral Energy Distribution of Galaxies, Proceedings of the International Astronomical Union, IAU Symposium, Volume 284, p. 468-470
Published in Aug 2012
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.
Free Keywords: galaxies: starburst; radio continuum
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