Blinnikov, Sergei | Search NASA

DOE OSTI2022

StaNdaRT: a repository of standardised test models and outputs for supernova radiative transfer

We present the first results of a comprehensive supernova (SN) radiative-transfer (RT) code-comparison initiative (StaNdaRT), where the emission from the same set of standardised test models is simulated by currently used RT codes. We ran a total of ten codes on a set of four benchmark ejecta models of Type Ia SNe. We consider two sub-Chandrasekhar-mass (M tot = 1.0 M ⊙ ) toy models with analytic density and composition profiles and two Chandrasekhar-mass delayed-detonation models that are outcomes of hydrodynamical simulations. We adopt spherical symmetry for all four models. The results of the different codes, including the light curves, spectra, and the evolution of several physical properties as a function of radius and time are provided in electronic form in a standard format via a public repository. We also include the detailed test model profiles and several Python scripts for accessing and presenting the input and output files. We also provide the code used to generate the toy models studied here. In this paper, we describe the test models, radiative-transfer codes, and output formats in detail, and provide access to the repository. We present example results of several key diagnostic features.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗

NASA NTRS1997

A comparative modeling of supernova 1993J

The light curve of Supernova 1993J is calculated using two computational radiation transport approaches. The two approaches are represented by the computer codes STELLA and EDDINGTON. The emphasis is on the shock breakout and the photometry in the U, B and V bands during the first 120 days of the supernova. The STELLA model includes implicit hydrodynamics and is able to model early supernova evolution before the expansion is homologous. The STELLA model employs multi-group photonics and is able to follow the radiation as it decouples from the matter. The EDDINGTON code uses an algorithm for integrating the transport equation which assumes homologous expansion and uses a finer frequency resolution. The agreement between the two codes is considered to be satisfactory only in the case where compatible physical assumptions are made concerning the opacity. The assumptions are justified. The continuum spectrum for SN 1993J is predicted near the shock breakout to be superior to that predicted by standard single energy group hydrocodes. The uncertainties involved in current time dependent models of supernova light curves are discussed.

Blinnikov, Sergei↗