Scientific Report



Organizers: Andy Howell, Dani Maoz, Paolo Mazzali, Gijs Nelemans, Jacco Vink


Scientific case and motivation

Type Ia supernovae are bright stellar explosions, observed in old as well as young stellar populations and are believed to be thermonuclear explosions of degenerate carbon-oxygen white dwarfs, most likely triggered by the compression of the objects as they grow in mass towards the Chandrasekhar limit. They are one of the main sites of nucleosynthesis in the Universe, being responsible for most of the iron ever produced. Their tight peak luminosity-light curve shape relation has enabled their use as distance indicators in cosmology, giving the first clues that the expansion of the Universe is accelerating. It is very frustrating and unfortunate that we don't know the configuration and trigger of the explosion, i.e. their direct progenitors. In this Lorentz workshop we brought together a significant fraction of the researchers working on the different observable signatures of the progenitors. The aim of the workshop was to discuss the best way forward for obtaining tight observational constraints on the

progenitors of type Ia supernovae in the next decade.


The workshop

A total of 50 participants from 10 countries have taken part in the workshop. The workshop had "assigned" talks in the mornings, giving overviews of the state-of-the-art in the different topics, some "hot" talks, showing new results and extended disussion sessions in the afternoons. The overview talks were an excellent setting of the scene and the discussions were lively and led to many interesting observations. It is clear that the Ia supernovae show great diversity and that improved theoretical modelling now predicts several observable progenitor signatures that can be searched for in existing and in particular in future observations. Several new results were presented, such as global delay time distributions, double white dwarf merger simulations and likely progenitor features in the SN spectra. X-ray and in particular Radio observations will soon put very tight constraints on the presence of circumstellar material.


Final remarks

The workshop was a great success. Many participants were very excited about the topics, the mix of participants and the set-up of the workshop and expressed the hope that a similar workshop would be repeated in a few years. The success was certainly also due to the excellent facilities and support of the Lorentz center. We also gratefully acknowledge funding from the Lorentz Center, NOVA, KNAW and NWO.