Observations and Theory of Supernovae

University Of Texas At Austin, Austin TX

Investigators

Abstract

This award will continue support for a research program primarily focused on the observation and theory of supernovae of both types: core collapse supernovae in which very massive stars end their lives in spectacular explosions following exhaustion of fuel in their cores, and Type Ia supernovae which likely arise when white dwarfs in close binaries accumulate too much mass from their neighbors and collapse. With regard to core collapse supernovae, asymmetries will be explored using spectropolarimetry, relating that data to information derived from systems for which the specific progenitor stars have been identified. Systematic differences in the polarization properties of hypernovae will also be investigated, especially in elements such as O and Ca. The study of gamma-ray bursts, supernovae, and their connection will be continued with the Robotic Optical Transient Search Experiment (ROTSE) telescope array and the ROTSE IIIb telescope at McDonald Observatory. The Texas Supernovae Search will also be continued with the ROTSE IIIb telescope and the Hobby-Eberly Telescope at McDonald will be used for rapid and time sampled spectroscopic follow-up. Core collapse supernovae will be studied with the Spitzer Space Telescope and core collapse supernovae discovered by the SDSS Supernova survey will be investigated. The nature of rotating magnetic collapse supermovae will be examined with spherical and multi-dimensional models. For Type Ia supernovae, optical, near-infrared, Spitzer Space Telescope mid-infrared spectroscopy, and optical spectropolarimetry observations will be obtained with the goal of better understanding the progenitor evolution, the explosion physics, and the capacity of Type Ia supernovae to facilitate accurate cosmological measurements. A growing data set of spectropolarimetry will be analyzed in this regard as well as time series of data obtained with the Texas Supernova Search using the ROTSE IIIb/Hobby-Eberly Telescope combination. Through participation in the Sloan Digital Sky Survey (SDSS) Supernova Survey, the red shift ''desert'' from red shift of 0.1 to 0.4 will continue to be filled in with time on the Hobby-Eberly Telescope being a principal contribution to this data set. The work carried out here is expected to have impact on many other areas of astronomy, notably stellar evolution, galactic evolution, and cosmology. National and international collaborations will be fostered through participation in the various consortia necessary for this work (SDSS, ROTSE, etc.). The results of this work will be integrated into various education and outreach efforts including a graduate course on supernovae, popular books, articles, and the StarDate radio program.