Pair-Instability Supernovae via Collision Runaway in Young Dense Star Clusters
Abstract
Stars with helium cores between ~64 and 133 M_sun are theoretically predicted to die as pair-instability supernovae. This requires very massive progenitors, which are theoretically prohibited for Pop II/I stars within the Galactic stellar mass limit due to mass loss via line-driven winds. However, the runaway collision of stars in a dense, young star cluster could create a merged star with sufficient mass to end its life as a pair-instability supernova, even with enhanced mass loss at non-zero metallicity. We show that the predicted rate from this mechanism is consistent with the inferred volumetric rate of roughly ~2x10^-9 Mpc^-3 yr^-1 of the two observed pair-instability supernovae, SN 2007bi and PTF 10nmn, neither of which have metal-free host galaxies. Contrary to prior literature, only pair-instability supernovae at low redshifts z<2 will be observable with the Large Synoptic Survey Telescope (LSST). We estimate the telescope will observe ~10^2 such events per year that originate from the collisional runaway mergers in clusters.
Keywords
Cite
@article{arxiv.1111.3648,
title = {Pair-Instability Supernovae via Collision Runaway in Young Dense Star Clusters},
author = {Tony Pan and Abraham Loeb and Daniel Kasen},
journal= {arXiv preprint arXiv:1111.3648},
year = {2012}
}
Comments
6 pages, 4 figures. Accepted MNRAS, incorporates recommendations of the referee