title: Distances with <4% precision from type Ia supernovae in young star-forming environments.
abstract: The luminosities of type Ia supernovae (SNe), the thermonuclear explosions of white-dwarf stars, vary systematically with their intrinsic color and the rate at which they fade. From images taken with the Galaxy Evolution Explorer (GALEX), we identified SNe Ia that erupted in environments that have high ultraviolet surface brightness and star-formation surface density. When we apply a steep model extinction law, we calibrate these SNe using their broadband optical light curves to within ~0.065 to 0.075 magnitude, corresponding to <4% in distance. The tight scatter, probably arising from a small dispersion among progenitor ages, suggests that variation in only one progenitor property primarily accounts for the relationship between their light-curve widths, colors, and luminosities.
authors: Department of Astronomy, University of California, Berkeley, CA 94720-3411, USA. pkelly@astro.berkeley.edu.
authors: Patrick L
authors: PL
authors: Kelly
authors: Department of Astronomy, University of California, Berkeley, CA 94720-3411, USA.
authors: Alexei V
authors: AV
authors: Filippenko
authors: SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA.
authors: David L
authors: DL
authors: Burke
authors: Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138, USA.
authors: Malcolm
authors: M
authors: Hicken
authors: Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, USA.
authors: Mohan
authors: M
authors: Ganeshalingam
authors: Department of Astronomy, University of California, Berkeley, CA 94720-3411, USA.
authors: WeiKang
authors: W
authors: Zheng