BEACONS IN THE DARK: USING NOVAE AND SUPERNOVAE TO DETECT DWARF GALAXIES IN THE LOCAL UNIVERSE

摘要

We propose that luminous transients, including novae and supernovae (SNe), can be used to detect the faintest galaxies in the universe. Beyond a few megaparsecs, dwarf galaxies with stellar masses. less than or similar to 10(6) M-circle dot will likely be too faint and/or too low in surface brightness to be directly detected in upcoming large area ground-based photometric surveys. However, single-epoch Large Synoptic Survey Telescope photometry will be able to detect novae to distances of similar to 30 Mpc and SNe to gigaparsec-scale distances. Depending on the form of the stellar mass-halo mass relation and the underlying star formation histories of low-mass dwarfs, the expected nova rates will be a few to similar to 100 yr(-1) and the expected SN rates (including both type Ia and core-collapse) will be similar to 10(2)-10(4) with in the observable (4 pi sr) volume. The transient rate associated with intrahalo stars will be comparably large, but these transients will be located close to bright galaxies, in contrast to the dwarfs, which should trace the underlying large-scale structure of the cosmic web. Aggressive follow-up of hostless transients has the potential to uncover the predicted enormous population of low-mass field dwarf galaxies.