Core-Collapse Supernovae: explosions mechanism and jet formation. G.S.Bisnovatyi-Kogan, Space Research Institute, Moscow. VIII Winter School on Theoretical Physics FROM NUCLEAR PHYSICS TO ASTROPHYSICS AND COSMOLOGY 31 January - 7 February, 2010, Dubna , Russia. Content.

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Core-Collapse Supernovae: explosions mechanism and jet formation

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Core-Collapse Supernovae: explosions mechanism and jet formation G.S.Bisnovatyi-Kogan, Space Research Institute, Moscow VIII Winter School on Theoretical Physics FROM NUCLEAR PHYSICS TO ASTROPHYSICS AND COSMOLOGY31 January - 7 February, 2010, Dubna, Russia

Content . 1. Presupernovae 2. Development of SN theory 3. Magnetorotational mechanism of explosion 4. Core collapse and formation of rapidly rotating neutron star. 5. Magnetorotational supernova explosion 6. Magnetorotational instability 7. Jet formation in magnetorotational explosion 8. Mirror symmetry breaking: Rapidly moving pulsars.

Explosion mechanisms of • spherically symmetric star • Thermonuclear explosion of C-O degenerate core (SN Ia) • Core collapse and formation of a neutron star, neutrino deposition • gravitational energy release up to 5 10 erg, carried away by neutrino (SN II, SN Ib,c) Equal to binding energy of the neutron star

In a simple 1-D model neurino deposition cannot give enough energy to matter (heating) for SN explosion Neutrino convection leads to emission of higher energy neutrino, may transfer more energy into heating Results are still controversial Transformation of the neutrino energy into kinetic one - ??? 1968: PULSARS – rapidly rotating, strongly magnetized neutron stars Magnetorotational explosion (MRE): transformation of the rotational energy of the neutron star into explosion energy by means of the magnetic field in core collapse SN

Most of supernova explosions and ejections are not spherically symmetrical. A lot of stars arerotating and have magnetic fields. Often we can see one-side ejections. Magnetorotational mechanism: transforms rotational energy of the star to the explosion energy. In the case of the differential rotation the rotational energy can be transformed to the explosion energy by magnetic fields. .

The magnetohydrodynamic rotational model of supernova explosion Astrophysics and Space Science, vol. 41, June 1976, p. 287-320 Calculations of supernova explosion are made using the one-dimensional nonstationary equations of magnetic hydrodynamics for the case of cylindrical symmetry. The energy source is supposed to be the rotational energy of the system (the neutron star in the center and the surrounding envelope). The magnetic field plays the role of a mechanism of the transfer of rotational momentum. The calculations show that the envelope splits up during the dynamical evolution of the system, the main part of the envelope joins the neutron star and becomes uniformly rotating with it, and the outer part of the envelope expands with large velocity, carrying out a considerable part of rotational energy and rotational momentum. These results correspond qualitatively with the observational picture of supernova explosions.

The main results of 1-D calculations: Magneto-rotational explosion (MRE) has an efficiency about 10% of rotational energy.For the neutron star mass the ejected mass 0.1М,Explosion energy 1051 ergEjected mass and explosion energy depend very weekly on the parameter Explosion time strongly depends on . tвзрыва~ Explosion time = • Small is difficult for numerical calculations with EXPLICIT numerical schemesbecause of the Courant restriction on the time step, “stiff” system of equations: • determines a “stiffness”. In 2-D numerical IMPLICIT schemes have been used.

Presupernova Core Collapse Ardeljan et. al., 2004, Astrophysics, 47, 47 Equations of state takes into account degeneracy of electrons and neutrons, relativity for the electrons, nuclear transitions and nuclear interactions. Temperature effects were taken into account approximately by the addition of the pressure of radiation and of an ideal gas. Neutrino losses and iron dissociation were taken into account in the energy equations. A cool iron white dwarf was considered at the stability border with a mass equal to the Chandrasekhar limit. To obtain the collapse we increase the density at each point by 20% and switch on a uniform rotation.

Gas dynamic equations with a self-gravitation, realistic equation of state, account of neutrino losses and iron dissociation F(,T) - neutrino losses -iron dissociation energy Neutrino losses: URCA processes, pair annihilation, photo production of neutrino, plasma neutrino Approximation of tables from Ivanova, Imshennik, Nadyozhin,1969

Initial State Spherically Symmetric configuration, Uniform rotation with angular velocity 2.519 (1/сек). Temperature distribution: + 20%Grid Density contours

2-D magnetorotational supernova N.V.Ardeljan, G.S.Bisnovatyi-Kogan, S.G.Moiseenko MNRAS, 359, 333 (2005) A magnetorotational core-collapse model with jets S. G. Moiseenko,G. S. Bisnovatyi-Koganand N. V. ArdeljanMNRAS 370, 501 (2006) Different Magneto-rotational Supernovae G. S. Bisnovatyi-Kogan, S. G. Moiseenko, and N. V. Ardelyan Astronomy Reports (2008)52, No. 12, 997-1008. Equations: MHD + self-gravitation, infinite conductivity. Axial symmetry () , equatorial symmetry (z=0).

Toroidal magnetic field amplification. pink – maximum_1 of Hf^2 blue – maximum_2 of Hf^2 Maximal values of Hf=2.5 10(16)G The magnetic field at the surface of the neutron star after the explosion is H=4 1012 Gs

MR supernova – different core masses BK, SM, Ard (2008) Dependence of the MR supernova explosion energy on the core mass Energy of the explosion of an MR supernova as a function of the initial mass of the core for various specific rotational energies before the start of the evolution of the magnetic field (before the collapse), Erot/Mcore (0.39-0.40) x 1019 erg/g (solid curve) and Erot/Mcore(0.19-0.23) x 1019 erg/g (dashed curve).

Toy model of the MRI development: expomemtial growth of the magnetic fields at initial stages MRI leads to formation of multiple poloidal differentially rotating vortexes. Angular velocity of vortexes is growing (linearly) with a growth of H.

CP violation in week processes in regular magnetic field: does not work, because MRI leads to formation of highly chaotic field. Astro-ph/0510229 MULTI-DIMENSIONAL RADIATIONHYDRODYNAMIC SIMULATIONS OF PROTONEUTRON STARCONVECTION L. Dessart, A. Burrows, E. Livne, C.D. Ott PNS convection is thus found to be a secondary feature of the core-collapse phenomenon, ratherthan a decisive ingredient for a successful explosion.

Violation of mirror symmetry of magnetic field (Bisnovatyi-Kogan, Moiseenko, 1992 Astron. Zh., 69, 563 (SvA, 1992, 36, 285) • Initial toroidal field • Initial dipole field • Generated toroidal field • Resulted toroidal field

In reality we have dipole + quadrupole + other multipoles… Wang J.C.L., Sulkanen M.E., Lovelace R.V.L. Asymmetry of Solar magnetic field The North-South Coronal Asymmetry with Inferred Magnetic Quadrupole Osherovich, V. A. et al.. Solar Wind Nine, Proceedings of the Ninth International Solar Wind Conference, Nantucket, MA, October 1998. AIP Conference Proceedings, 471, 721 (1999) In magnetorotational supernova Kick velocity, along the rotational axis, due to the asymmetry of the magnetic field ~ up to 300km/sec Kich along the rotational axis even in the case of inclined dipole – jets along rotational axis. Hanawa et al. AIP Conf. Series 359, 158 (2006)

Dependenceof the week interaction cross-section on the magnetic fieldstrength lead to the asymmetricneutrino flux and formation of rapidlymooving pulsars due to the recoil action as well asrapidly moving black holes. Neutrino heat conductivity neutrino opacity energy flux The anisotropy of the flux Kick velocity along the rotational axis