The fate and properties of massive stars the

The fate and properties of massive stars, the progenitors of CCSN. The reasons of collapse. The dynamic of collapse and processes during it

Hertzsprung-Russell diagram Image: Wiki, credits ESO https: //www. eso. org/public/images/eso 0728 c/

Stars

M<8 MSUN Quiet envelope ejection, white dwarf formation (WD) i=isolated b=binary WD i, b WD SN Ia b M=(8— 25 ) MSUN Supernova (SN) explosion, neutron star (NS) formation Normal star Giant star NS NS i, b b BH BH M>25 MSUN Collapse to black hole (BH)? WD, NS, BH = star’s cemetery Adapted from D. G. Yakovlev, “Nuclear burning in superdense matter”, Pushino (2010)

From: Georg G. Raffelt Proceedings ISAPP School Neutrino Physics and Astrophysics

Supernova 1994 D in Galaxy NGC 4526

Three characteristic stellar timescales Hydrodynamic timescale Thermal timescale Nuclear timescale

Main factors, determining the structure and the evolution of massive stars § Rotation § Turbulent convection § Large-scale (meridional) circulation § Mass loss by stellar wind § Energy losses due to neutrino emission (especially on late stages of evolution)

From: H. -Th. Janka “Explosion Mechanisms of CCSN”

Weaver, Zimmerman, Woosley Ap. J v. 225, p. 1021 (1978)

Onion stellar structure just before collapse

Neutrino processes in a presupernova Electron-positron pair annihilation

Plasma neutrino process

Photoneutrino process in the Coulomb fields of atomic nuclei and electrons The URCA process Gamow & Schönberg (Phys. Rev. 1940, 1941)

M. Kutschera, A. Odrzywolek, M. Misiaszek “Presupernova as powerful neutrino sources”

During Si-burning phase 1 neutron/day/kiloton of water 1 kpc distance

Credit: Copyright 2010 Haubois/Perrin (LESIA, Observatoire de Paris) Red Supergiant Distance ~ 200 pc Mass ~ 12 Solar Radius ~ 800 Solar Luminosity ~ 100 000 Solar

From Woosley & Weaver An. Rev. Astron. Astrophys. v. 24, p. 205 (1986)

Expanding force: Dynamical stability Contracting force: Hydrostatics: Stability: 3γ − 2 > 2 γ > 4/3

Stellar equilibrium Virial theorem: Negative heat capacity Stability Critical value

White dwarfs Gravitation – baryons, pressure support – degenerate electrons 1. Non-relativistic electrons From virial theorem 2. Relativistic electrons S. Chandrasekhar

From: D. Nadyozhin, Lectures ITEP

The ravine of instability

Dynamics of gravitational collapse Initial “free fall”. Accreting shock wave A homogeneous sphere of a mass and radius : Schematic view

Foglizzo et al (2015) Janka et al (2012)