Speaker: Prof. Doron Kushnir (Weizmann Institute of Science)
Title: All known Type Ia supernova models fail to reproduce the observed luminosity-width correlation
Abstract:
The primary power source of optical emission in Type Ia supernovae is gamma-rays from the radioactive decay of 56Ni, synthesized during the explosion. As the ejecta expands, it becomes increasingly transparent, allowing gamma rays to escape. The gamma-ray escape time, t0, can be measured with high precision using an integral relation we derived, independent of the supernova distance. By combining t0 with the synthesized 56Ni mass (MNi56), we identified a strong correlation between t0 and MNi56. This observed relation is similar to the well-known Phillips relation, which links light curve width to peak luminosity. However, unlike the Phillips relation, comparing models to the t0-MNi56 relation bypasses radiation transfer calculations, as the ejecta properties directly determine t0.
Accurately modeling thermonuclear supernovae requires solving hydrodynamic equations coupled with nuclear-burning networks involving hundreds of isotopes—currently infeasible in multidimensional full-star simulations. In particular, thermonuclear detonation waves (TNDWs), crucial to such explosions, remain unresolved. We developed a new numerical scheme that accelerates calculations by orders of magnitude while preserving accuracy. The scheme includes (1) a burning limiter that broadens the TNDW while maintaining internal structure and (2) an adaptive grouping of isotopes in quasi-nuclear-statistical equilibrium, optimizing burning calculations. Our method achieves percent-level accuracy in multidimensional simulations and enables, for the first time, reliable modeling of progenitor scenarios for thermonuclear supernovae. Applying our scheme, we found that all existing Type Ia supernova models fail to reproduce the observed t0-MNi56 relation.
Zoom link:
https://huji.zoom.us/j/83355692848?pwd=hw5DoMQzT96tqICriwyQC29YGcn8dR.1
Meeting ID: 833 5569 2848
Passcode: 398006
Contact: David Barba González