Non-equilibrium Radioactive Transfer and Kinetics of Nuclear Reactions in the Theory of SUPERNOVA Stars.
Tech Area / Field
8 Project completed
Senior Project Manager
Evstyukhin K N
VNIIEF, Russia, N. Novgorod reg., Sarov
- ITEF (ITEP), Russia, Moscow
- Max-Planck-Institut für Astrophysik, Germany, Garching\nCEA / DSM / DAPNIA/CEN Saclay, France, Saclay
Project summaryIt is proposed to use the achievements in the field of numerical simulations of the radiation hydrodynamics (RHD) and in the nuclear kinetics (ITEP, VNIIEF, and MPA) together with the supernova (SN) database (SAI MSU) to solve certain astrophysical problems related to the nature of supernovae (SNe).
At present, calculations of SN light curves and spectra, based on complicated mathematical modeling, prove to be an important source of detailed information about various processes inside massive stars. Hydrodynamical computations of the final stages of stellar evolution accounting for nonequilibrium radiative transfer and kinetics of nucleosynthesis demand large computational resources. Recently, the usage of the most modern methods of observational astrophysics has yielded a large amount of high-quality data at all wavelengths from radio through gammarays and, moreover, the neutrino emission from SN 1987A has been detected. Problems associated with SN physics are studied in many large foreign astrophysical centers (S. Woosley, University of California; J.C. Wheeler, University of Texas; K. Nomoto, Tokyo; W. Hillebrandt and E. Muller, MPA; I.J. Danziger et al., ESO) including some national laboratories of western countries (Livermore, Los Alamos, USA; INFN, Italy). This is due to the fact that the SN studies incorporate many fields of modern theoretical and mathematical physics.
The main goal of the Project is the further development of the theory of SN spectra and light curves accounting for the non-equilibrium radiative transfer and kinetics of nuclear reactions during SN explosion. From Russian side, highly qualified specialists will be employed in the Project. Earlier many of them took part in defence programs. Two groups of scientists from MPA (FRG) headed by Prof. Wolfgang Hillebrandt and from University of California (USA) headed by Prof. Stan Woosley will take part in the Project from the Western side.
As a result of the Project, a mathematical RHD model of final stages of massive star evolution allowing for the non-equilibrium radiative transfer should be created. The model should be realized as a package of computer programs intended for the calculations of either model or real light curves and evolution of SN spectra. It is planned to carry out calculations for inpidual SNe of different types, getting more detailed information on the nature of these phenomena, in particular, on the explosion mechanism. Besides, such parameters as the explosion energy and the ejected mass could be obtained, while calculations of the nuclear reaction kinetics could be used to establish the site of element synthesis beyond the iron peak.
New numerical schemes, algorithms and corresponding software will be developed during the work on the Project. These schemes will accelerate considerably the integration of the complex systems of partial differential equations, which have many important applications. Separate blocks of this software package will also be valuable since they could be adapted to a number of practical problems involving the solution of stiff systems of differential equations. For example, some problems of complicated chemical kinetics may be solved by using this package. Moreover, a broad class of physical phenomena and devices can be studied with the aid of models based on the approximation of multi-component medium with non-equilibrium radiative transfer. The package for time-dependent radiative transfer can be applied to many problems in plasma physics, e.g. in simulations of targets for the laser thermonuclear fusion.
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