2024/07/10 by Amir Sharon, Sharon, Amir, Doron Kushnir +3
Physics and Astronomy · #FOS: Physical sciences #Gamma-ray bursts and supernovae #High Energy Astrophysical Phenomena (astro-ph.HE) #Particle physics theoretical and experimental studies
paper · pdf · doi:10.48550/arxiv.2407.07417
openalex publication_date 2024/07/10 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
A rare subclass of Type Ia supernovae (SNe Ia), named after the prototype SN 2003fg, includes some of the brightest SNe Ia, often called "super Chandrasekhar-mass" SNe Ia. We calculate the γ-ray deposition histories and the 56Ni mass synthesized in the explosion, MNi56, for eight 2003fg-like SNe. Our findings reveal that the γ-ray escape time, t0, for these objects is t0≈45-60 days, significantly higher than that of normal SNe Ia. 2003fg-like SNe are distinct from normal SNe Ia in the t0 - MNi56 plane, with a noticeable gap between the two populations. The observed position of 2003fg-like SNe in this plane poses a significant challenge for theoretical explosion models. We demonstrate that the merger of two white dwarfs (WDs) and a single star exceeding the Chandrasekhar limit fail to reproduce the observed t0 - MNi56 distribution. However, preliminary calculations of head-on collisions of massive WDs show agreement with the observed t0 - MNi56 distribution.