Friday, November 20, 2009, Noon, Phillips Auditorium
Evolution of Type Ia Supernovae:
Insights from
a Study of the Large-Scale Environments of Local Hosts
Dr. Michael Cooper, Steward Observatory
| Over the past 20 years, type Ia supernovae have been employed as cosmological probes with great success, allowing distances to be measured out to intermediate redshifts and providing increasingly strong constraints on fundamental cosmological parameters. Looking towards the next 20 years, several large space- and ground-based facilities are planned, with the goal of using supernovae to measure cosmological parameters at exceedingly high precision. In order for these future facilities to achieve their ambitious goals, systematic effects must be understood at the one percent level or better. However, to date, evolution in the supernova population has been largely overlooked as a potential systematic bias. In this talk, I will present results from a recent analysis of the large-scale environments of local type Ia supernovae, which provide an intriguing constraint on the properties of type Ia progenitors in star-forming galaxies and which reveal a potential metallicity bias in the luminosity of type Ia events that must be better understood in order for supernovae to be confidently employed as high-precision cosmological probes. |
