A Search For Failed Supernovae and Other Observational Constraints on the Supernova Mechanism

A research team at the Ohio State University will carry out a project to better understand the fates of massive stars and the formation of black holes using a multifaceted observational and theoretical approach. Understanding the formation of black holes is of enormous importance as scientists detect more black hole mergers with gravitational wave instruments. The centerpiece is a unique project using the twin 8.4m Large Binocular Telescope (LBT) to monitor all the massive, evolved stars in 27 nearby star-forming galaxies. The primary goals of the project are to (1) Measure the fraction of massive star core collapses that fail, producing a black hole without a supernova (SN) explosion, and characterize the properties of these failed supernovae; (2) Measure the properties of SN progenitors, in particular with pioneering studies of their variability; and (3) Characterize the multiplicity of stars just before and after death. While doing so, the project will advance the training of students and postdoctoral researchers and broaden the public’s understanding and interest in science, aided by their fascination with stars and their complicated roads to death. Searches for the progenitors of SNe are finding a deficit of high mass progenitors. This problem can be solved if 20% of core collapses fail and produce a black hole without a SN explosion. This failed SN fraction also naturally explains the compact object mass function. The research team has already identified one excellent candidate, implying a failure fraction of 16%. During the current project they will further confirm this candidate, identify others, and better constrain the fraction of core collapses that fail. Very few SN progenitors are well characterized, making it difficult to determine the mapping between progenitors and outcomes. The project will characterize progenitors of SN in the LBT survey, pioneer constraints on the progenitors of Galactic supernovae, and better characterize and improve constraints on progenitors using local stellar populations. Multiplicity and binary interactions are crucial to understanding anything about the evolution of massive stars, supernovae and gravitational wave merger events. The project will expand on pioneering studies constraining the multiplicity of stars just before and after their deaths, in particular by accurately determining the distances to Galactic SN remnants. This award advances the goals of the Windows on the Universe Big Idea. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.