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The International Supernova Program (ISP)

Final Report Summary - ISP (The International Supernova Program)

Project objectives

This project was designed to provide follow-up observations for core-collapse supernovae (SNe) from unbiased (blind) supernova (SN) surveys. The two focal goals were to study SNe in low-metallicity galaxies and to discover new types of SNe.

Work performed

ISP has achieved all its intended goals with great success. Initially, the Supenrova Factory (SNF) survey was used as a ‘feeder’ survey, and it has now been replaced by the new and powerful Palomar Transient Factory (PTF), which has been active since March 2009 and has so far discovered more than 1 400 new supernovae. Details on the PTF are available on the project webpage (see http://www.astro.caltech.edu/ptf/ for further details) as well as in our two published project papers (Law et al., 2009, PASP, 121, 1395; Rau et al., 2009, PASP, 121, 334) on which I am a co-author. Ten additional papers were published by my group within the PTF, including one in Nature (Quimby et al., 2011).

Follow-up infrastructure is also in place. We regularly follow-up PTF discoveries using numerous telescopes, including the 1 m telescope in the Wise Observatory (Israel), the 1.5 m robotic telescope and the 5 m Hale telescope at Palomar Observatory (USA), the 4.2 m WHT telescope at La Palma Observatory (Spain) and the 10 m Keck telescope in Hawaii (USA).

A high-profile result from this project (based on SNF data) has been published in Nature (Gal-Yam et al. 2009, Nature, 426, 642), while an additional publication, based on new PTF data is Quimby et al., 2011 (Nature, 474, 487). Both report discoveries of new supernova types.

Our second main goal (the study of supernovae in low-metallicity galaxies) has also been achieved. My student, Iair Arcavi, has shown in a paper we published in 2010 (ApJ, 721, 777) that events in low-luminosity, low-metallicity galaxies are different from those previously studied (based on samples found in large, high-metallicity galaxies). A paper in preparation shows these results are robust, based on a much larger sample from PTF (>360 events).

Main results

To conclude, the project has helped establish an international research network that is currently running the most powerful surveys for supernovae. It has characterised the properties of supernovae in dwarf galaxies and discovered new types of explosions.