Workshop held at the Lorentz-Center of Leiden UniversityJuly 15-26, 2002
Type Ia Supernovae --- objects which we believe are thermonuclear explosions of white dwarf stars --- are among the brightest individual objects in the Universe, and have ptical luminosities which can be calibrated to better than 7 percent. As such they have been used to measure cosmological distances, with the remarkable result that our universe appears to be accelerating in its expansion. In addition, as the principal producer of iron, these events also drive the chemical evolution of galaxies. Unfortunately, despite being a major focus of astrophysical research, fundamental questions about their physical and observational nature still remain.
What are their progenitors? We believe SN Ia represent the explosions of White Dwarf stars, and that the explosion mechanism requires the transfer of mass through a binary system. However, the nature of progenitor binary systems which lead to SN Ia is still unknown; no compelling solution has been found. New evolutionary models and new observations are needed to help answer this question.
How do Type Ia supernovae explode and shine? Turbulent process during the explosion of a white dwarf and the interaction of radiation with the rapidly expanding matter need to be understood.
Is the Universe Accelerating, or are we simply observing changes in the mean SN observational properties with redshift? Such effects may arise from a dependance of the supernova explosions or their progenitor properties on metallicity, or could be due to observational biases.
To make progress on the above topics, theory and observations need to work hand in hand to pose, and then answer, a new set of observational questions which can distinguish between competing models. This Lorentz Centre workshop is dedicated to posing tests which will provide theoretical insight, but are observationally practical, by bringing together leading theorists and observationalist from the broad range of disciplines which represents SN Ia research.
Brian Schmidt firstname.lastname@example.org
Norbert Langer N.Langer@astro.uu.nl