AR 16603 (Archival Research)

Sun Jul 14 10:48:42 GMT 2024

Principal Investigator: Emma Beasor
PI Institution: University of Arizona
Investigators (xml)

Title: Using supernova progenitors to determine the mass threshold for black hole formation
Cycle: 29

There is growing consensus amongst theorists that massive stars above 20Msun should collapse immediately to black holes (BHs) with little or no visible explosion, and while empirical evidence suggests there is a lack of SN progenitors above this mass detected via pre-explosion imaging, the statistical significance of this result is weak. Here, we are proposing to analyse 6 SN that each have both pre-explosion and late-time imaging available in the archive, but which have not had their progenitor masses estimated using image subtraction techniques. By returning to the sites, we will be able to 1) confirm the disappearance of the suspected progenitor and 2) increase the accuracy of progenitor mass estimates by using the image subtraction technique. The masses estimated for each of these objects will be complimented with masses determined for 4 further SN progenitors for which we are submitting a separate GO proposal, each with pre-explosion and but which have not been followed up at late times. If these 10 progenitors all follow the same mass distribution as those already in the sample, the 20 Msun BH threshold mass will reach the statistical significance necessary (4.4 sigma) to be considered a confirmation. If however these progenitors are higher in mass, the statistical significance of the lack of progenitors above 20 Msun is weakened, and could possibly imply a higher threshold for BH formation.