2025/05/31 by Mattias Ergon, M. Ergon, Ergon, Mattias +11 · 1 voice · 1 citation
Chemistry · Engineering · Physics and Astronomy · #Advanced NMR Techniques and Applications #Atomic and Subatomic Physics Research #FOS: Physical sciences #High Energy Astrophysical Phenomena (astro-ph.HE) #Solar and Stellar Astrophysics (astro-ph.SR) #Superconducting Materials and Applications #astro-ph.HE #astro-ph.SR
paper · pdf · doi:10.48550/arxiv.2506.00543
openalex publication_date 2025/05/31 · arxiv published 2025/05/31 · arxiv updated 2025/05/31 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We present HYDE, a new one-dimensional hydrodynamical code, and use it to construct a grid of supernova (SN) models based on solar-metallicity bare helium-core models evolved to the verge of core-collapse with MESA STAR. This grid is suited to model Type IIb SNe, which progenitor stars are thought to have lost all but a tiny fraction of their hydrogen envelopes. Using an automated procedure we fit the bolometric lightcurves and photospheric velocities for a large sample of (17) Type IIb SNe to the grid of SN models. We find that the distribution of initial masses for the sample can be reasonably well described by a standard Salpeter IMF, although there is an under-population in the >25 M_\odot range. The fractions of SNe with initial masses <15 M_\odot and <20 M_\odot are 56 and 81 percent, respectively, suggesting either the binary channel to dominate the production of Type IIb SNe or a flaw in our understanding of single-star mass-loss. We find correlations between the explosion energy, initial mass and mass of 56Ni; the explosion energy increases with initial mass and the mass of 56Ni increases with explosion energy. The method used allows us to determine the errors in the model parameters arising from the observed quantities and the degeneracy of the solution. We find that an error in the distance and extinction propagates mainly to the derived mass of 56Ni, whereas an error in the photospheric velocity propagates mainly to the derived helium-core mass and explosion energy. Fits using the bolometric lightcurve alone are completely degenerate along the Mej2/Eej=const curve, whereas fits using also the photospheric velocities are quite robust for well-sampled SNe. Finally, we provide a description and tests of the HYDE code, and a discussion of the limitations of the method used.