2019-04-12 Abstract

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Title: 3D numerical modeling from supernovae to their supernova remnants: the dynamical and chemical evolution for the case of SN 1987A
 
Speaker:  Dr. Masaomi Ono  (RIKEN, Japan)
 
Date: April 12 at 15:30
 
Location: R521, General building II
 
Abstract:
 From the discovery of SN 1987A, more than 30 years have passed, and it provides a unique opportunity to investigate the evolution from supernovae to their supernova remnants. Generally, in theoretical studies of supernova remnants, spherical symmetry has been commonly assumed for the supernova explosion. Observations of galactic supernova remnants, e.g., Cassiopeia A (Cas A) and SN 1987A, however, have shown that the morphology of the inner ejecta is apparently non-spherical. As for SN 1987A, the origin of the triple-ring structure in the nebula and the formation process of the progenitor star, Sk -69 202,  have not been elucidated. Additionally, recent observations of SN 1987A by ALMA have revealed that the three-dimensional distribution of the innermost molecular gas of CO and SiO is also non-spherical. From theoretical point of view, multi-dimensionality is essential for core-collapse
supernova explosions and additional asymmetry could also be introduced during the shock wave propagation in the progenitor star by matter mixing. 
 
  Then, we perform three-dimensional hydrodynamic/magneto hydrodynamic (MHD) simulation from the core-collapse supernova to the supernova remnant of SN 1987A for the first time. As the initial condition for SN 1987A, progenitor models based on a conventional single star scenario and a recent progenitor model based on a slow-merger scenario are used to investigate the impact. Explosions are initiated in an ad-hoc way taking into account the asymmetries of the explosions. Based on the results of the hydro/MHD simulation, distribution of the line of sight velocity of 56Ni, X-ray light curves, and the configuration of elements are discussed by comparing the observations. Moreover, we perform molecule formation calculation with a small molecule formation network based on the results of the three-dimensional simulation for the first time.
 
  As a result, a model with the progenitor model based on the slow-merger scenario and a globally bipolar explosion explains several observational features, the Doppler velocity distribution of [Fe II] lines, X-ray light curves, and the overall configuration of CO and SiO molecules well compared with that based on other progenitor models.
 
  Finally, we introduce future prospects including applications to other supernova remnants, e.g., Cas A, dust formation/destruction in core-collapse supernova ejecta.