The Uncertain Masses of Progenitors of Core Collapse Supernovae and Direct Collapse Black Holes

• Published in: arXiv.org 2020-01
• Main Authors: Farrell, Eoin, Groh, Jose, Meynet, Georges, Eldridge, J J
• Format: Article
• Language: English
• Subjects: Astronomical models; Black holes; Collapse; Convection; Initial mass function; Luminosity; Progenitors (astrophysics); Red giant stars; Stellar models; Supergiant stars; Supernovae
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.2001.08711

We show that it is not possible to determine the final mass \(M_{\rm fin}\) of a red supergiant (RSG) at the pre-supernova (SN) stage from its luminosity \(L\) and effective temperature \(T_{\rm eff}\) alone. Using a grid of stellar models, we demonstrate that for a given value of \(L\) and \(T_{\rm eff}\), a RSG can have a range of \(M_{\rm fin}\) as wide as 3 to \(45~\mathrm{M}_{\odot}\). While the probability distribution within these limits is not flat, any individual determination of \(M_{\rm fin}\) for a RSG will be degenerate. This makes it difficult to determine its evolutionary history and to map \(M_{\rm fin}\) to an initial mass. Single stars produce a narrower range that is difficult to accurately determine without making strong assumptions about mass loss, convection, and rotation. Binaries would produce a wider range of RSG \(M_{\rm fin}\). However, the final Helium core mass M\(_{\rm He-core}\) is well determined by the final luminosity and we find \(\log (\mathrm{M}_{\rm He-core}/M_{\odot}) = 0.659 \log (L/\mathrm{L}_{\odot}) -2.630\) Using this relationship, we derive M\(_{\rm He-core}\) for directly imaged SN progenitors and one failed SN candidate. The value of \(M_{\rm fin}\) for stripped star progenitors of SNe IIb is better constrained by \(L\) and \(T_{\rm eff}\) due to the dependence of \(T_{\rm eff}\) on the envelope mass \(M_{\rm env}\) for \(M_{\rm env} \lesssim 1~\)M\(_{\odot}\). Given the initial mass function, our results apply to the majority of progenitors of core collapse SNe, failed SNe and direct collapse black holes.