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Title: Cassiopeia A: Supernova explosion and expansion simulations under strong asymmetry conditions

Abstract

We propose a model for the explosion of a supernova and the expansion of its ejecta in the presence of a strong initial asymmetry (at the explosion time) in the central part of the star (core) and a possible smallscale asymmetry in the peripheral regions. The Chandra and NuSTAR observations of ejecta in the Cassiopeia A supernova remnant are analyzed. Based on our 1D and 2D numerical simulations performed using the DIANA and NUTCY codes, we propose a model for the explosion and expansion of ejecta that explains the observed experimental data where the materials initially located in the central region of the star end up on the periphery of the cloud of ejecta.

Authors:
;  [1];  [2];  [1]
  1. Russian Academy of Sciences, Lebedev Physics Institute (Russian Federation)
  2. Russian Academy of Sciences, Keldysh Institute of Applied Mathematics (Russian Federation)
Publication Date:
OSTI Identifier:
22617188
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Experimental and Theoretical Physics; Journal Volume: 123; Journal Issue: 3; Other Information: Copyright (c) 2016 Pleiades Publishing, Inc.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ASYMMETRY; COMPUTERIZED SIMULATION; EXPANSION; EXPLOSIONS; STARS; SUPERNOVA REMNANTS; USA

Citation Formats

Yakhin, R. A., E-mail: yakhin.rafael@gmail.com, Rozanov, V. B., Zmitrenko, N. V., and Stepanov, R. V.. Cassiopeia A: Supernova explosion and expansion simulations under strong asymmetry conditions. United States: N. p., 2016. Web. doi:10.1134/S1063776116090107.
Yakhin, R. A., E-mail: yakhin.rafael@gmail.com, Rozanov, V. B., Zmitrenko, N. V., & Stepanov, R. V.. Cassiopeia A: Supernova explosion and expansion simulations under strong asymmetry conditions. United States. doi:10.1134/S1063776116090107.
Yakhin, R. A., E-mail: yakhin.rafael@gmail.com, Rozanov, V. B., Zmitrenko, N. V., and Stepanov, R. V.. 2016. "Cassiopeia A: Supernova explosion and expansion simulations under strong asymmetry conditions". United States. doi:10.1134/S1063776116090107.
@article{osti_22617188,
title = {Cassiopeia A: Supernova explosion and expansion simulations under strong asymmetry conditions},
author = {Yakhin, R. A., E-mail: yakhin.rafael@gmail.com and Rozanov, V. B. and Zmitrenko, N. V. and Stepanov, R. V.},
abstractNote = {We propose a model for the explosion of a supernova and the expansion of its ejecta in the presence of a strong initial asymmetry (at the explosion time) in the central part of the star (core) and a possible smallscale asymmetry in the peripheral regions. The Chandra and NuSTAR observations of ejecta in the Cassiopeia A supernova remnant are analyzed. Based on our 1D and 2D numerical simulations performed using the DIANA and NUTCY codes, we propose a model for the explosion and expansion of ejecta that explains the observed experimental data where the materials initially located in the central region of the star end up on the periphery of the cloud of ejecta.},
doi = {10.1134/S1063776116090107},
journal = {Journal of Experimental and Theoretical Physics},
number = 3,
volume = 123,
place = {United States},
year = 2016,
month = 9
}
  • The remnants of core-collapse supernovae (SNe) have complex morphologies that may reflect asymmetries and structures developed during the progenitor SN explosion. Here we investigate how the morphology of the supernova remnant Cassiopeia A (Cas A) reflects the characteristics of the progenitor SN with the aim of deriving the energies and masses of the post-explosion anisotropies responsible for the observed spatial distribution of Fe and Si/S. We model the evolution of Cas A from the immediate aftermath of the progenitor SN to the three-dimensional interaction of the remnant with the surrounding medium. The post-explosion structure of the ejecta is described bymore » small-scale clumping of material and larger-scale anisotropies. The hydrodynamic multi-species simulations consider an appropriate post-explosion isotopic composition of the ejecta. The observed average expansion rate and shock velocities can be well reproduced by models with ejecta mass M {sub ej} ≈ 4 M {sub ⊙} and explosion energy E {sub SN} ≈ 2.3 × 10{sup 51} erg. The post-explosion anisotropies (pistons) reproduce the observed distributions of Fe and Si/S if they had a total mass of ≈0.25 M {sub ⊙} and a total kinetic energy of ≈1.5 × 10{sup 50} erg. The pistons produce a spatial inversion of ejecta layers at the epoch of Cas A, leading to the Si/S-rich ejecta physically interior to the Fe-rich ejecta. The pistons are also responsible for the development of the bright rings of Si/S-rich material which form at the intersection between the reverse shock and the material accumulated around the pistons during their propagation. Our result supports the idea that the bulk of asymmetries observed in Cas A are intrinsic to the explosion.« less
  • X-ray observations of the Cassiopeia A supernova remnant reveal explosive nucleosynthesis products such as Si and Fe, and thus provide a unique window into the core-collapse explosion that formed the remnant 330 years ago. We review current progress using X-ray spectra extracted on arcsecond angular scales from a 106 s Chandra observation of Cas A, in conjunction with models that follow the remnant's hydrodynamical evolution and treat the relevant plasma microphysics. We address questions related to the explosion such as the degree of explosion asymmetry, the nature of the jets, the nature of the circumstellar environment, and extent of radialmore » mixing of the Fe ejecta.« less
  • The shock compressibility of porous quartz (with initial density p{sub oo}=1.35 and 1.75 g/cm{sup 3}), plexiglass, and aluminum was investigated at pressures of 1.8, 2.0, 0.6, and 0.54 TPa, respectively. Experimental data were obtained on the two-stage compressibility of aluminum at 1.4 TPa. 29 refs., 5 figs., 2 tabs.
  • Here, we report on observations of the supernova remnant Cassiopeia A in the energy range from 100 MeV to 100 GeV using 44 months of observations from the Large Area Telescope on board the Fermi Gamma-Ray Space Telescope. We perform a detailed spectral analysis of this source and report on a low-energy break in the spectrum atmore » $$1.72^{+1.35}_{-0.89}$$ GeV. By comparing the results with models for the gamma-ray emission, we find that hadronic emission is preferred for the GeV energy range.« less
  • Neutrinos play important roles in the pre-collapse evolution, explosion, and aftermath of core-collapse supernovae. Detected neutrino signals from core-collapse supernovae would provide insight into the explosion mechanism and unknown neutrino mixing parameters. Achieving these goals requires large-scale, multiphysics simulations. For many years, several groups have performed such simulations with increasing realism. Current simulations and plans for future work of the Oak Ridge group are described.