The Cosmic Core-collapse Supernova Rate does not match the Massive-Star Formation Rate

Understand

We identify a "supernova rate problem": the measured cosmic core-collapse supernova rate is a factor of ~ 2 smaller (with significance ~ 2 sigma) than that predicted from the measured cosmic massive-star formation rate.

• The comparison is critical for topics from galaxy evolution and enrichment to the abundance of neutron stars and black holes.
• We systematically explore possible resolutions.
• The accuracy and precision of the star formation rate data and conversion to the supernova rate are well supported, and proposed changes would have far-reaching consequences.