A COMPARATIVE STUDY OF HYPERON EQUATIONS OF STATE IN SUPERNOVA SIMULATIONS

Abstract

A comparative study of the $\\Lambda$ hyperon equations of state of Banik,\nHempel and Banyopadhyay (BHB) \\citep{bhb} and \\citet{shen11} (denoted as HShen\n$\\Lambda$) for core collapse supernova (CCSN) simulations is carried out in\nthis work. The dynamical evolution of a protoneutron star (PNS) into a black\nhole is investigated in core collapse supernova simulations in the general\nrelativistic one dimensional code using the BHB$\\Lambda \\phi$ and HShen\n$\\Lambda$ equation of state (EoS) tables and different progenitor models from\nWoosley and Heger \\citep{Woos}. Radial profiles of the mass fractions of\nbaryons, the density as well as the temperature in the PNS at different moments\nin time, are compared for both EoS tables. The behaviour of the central density\nof the PNS with time is demonstrated for those two $\\Lambda$ hyperon EoS tables\nand compared with their corresponding nuclear EoS tables. It is observed that\nthe black hole formation time is higher in the BHB$\\Lambda \\phi$ case than in\nthe HShen $\\Lambda$ EoS for the entire set of progenitor models adopted here,\nbecause the repulsive $\\Lambda$-$\\Lambda$ interaction makes the BHB$\\Lambda\n\\phi$ EoS stiffer. Neutrino emission with the $\\Lambda$ hyperon EoS ceases\nearlier than that of its nuclear counterpart. The long duration evolution of\nthe shock radius and gravitational mass of the PNS after a successful supernova\nexplosion with enhanced neutrino heating are studied with the BHB$\\Lambda \\phi$\nEoS and $s$20WH07 progenitor model. The PNS is found to remain stable for 4 s\nand might evolve into a cold neutron star.\n