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IPN Orsay Université Paris Sud 11 CEA, DAM, DIF

IPN Orsay Université Paris Sud 11 CEA, DAM, DIF. Università degli Studi di Milano Dipartimento di Fisica INFN, Sezione di Milano. Impact of electro-weak processes during core-collapse phase of type II Supernovae.

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IPN Orsay Université Paris Sud 11 CEA, DAM, DIF

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  1. IPN Orsay Université Paris Sud 11 CEA, DAM, DIF Università degli Studi di Milano Dipartimento di Fisica INFN, Sezione di Milano Impact of electro-weak processes during core-collapse phase of type II Supernovae Anthea F. FANTINA & Patrick BLOTTIAU (IPNO & Univ.Milano) (Cea,Dam,Dif) Dr. E. Khan, Dr. J. Margueron (IPN Orsay) Dr. Ph. Mellor (CEA, DAM, DIF) Dr. J. Novak, Dr. Micaela Oertel (Luth, Meudon) Prof. P. Pizzochero & Dr. P. Donati (Univ. Milano & INFN) CoCoNut meeting 2009, Valencia 04th - 06th November

  2. We investigate … … electro-weak processes in core collapse supernova • Nuclear inputs: • electron capture rates • nucleon effective masses and Esym(T) via m*(T) • EoS • Hydrodynamics: • → one-zone code ( Fantina A.F. et al., Phys. Lett. B676, 140 (2009) ) • → 1D Newtonian code( Blottiau P., PhD thesis (1989) ) • → 1D Relativistic code( Romero J. et al., Astroph. J. 462, 839 (1996) ) A. F. Fantina & P. Blottiau - CoCoNuT meeting 2009

  3. … in particular: m*(T) and Esym(T) … influence of T-dependence of nuclear symmetry energy during core-collapse phase • Donati P. et al, Phys. Rev. Lett. 72, 2835 (1994) study of m*(T): 98Mo, 64Zn, 64Niin the range 0 < T < 2 MeV (QRPA) • decrease of m*(T) in the range 0 < T < 2 MeV • increase of Esym(~ 8%) • effects on gravitational collapse not negligible • Dean D.J. et al, Phys. Rev. C66, 31801 (2002) study of Esym(T): A = 56-66 in the range 0.33 < T < 1.23 MeV (SMMC) • increase of Esym (~ 6%) consistent with Donati et al. • “not significant changes for the collapse trajectory” A. F. Fantina & P. Blottiau - CoCoNuT meeting 2009

  4. DN ≈ 3 MeV mn mp Effective mass Symmetry energy Ylept,tr Donati P. et al., Phys.Rev.Lett. 74 (1994) Esymm(T) analogy with Fermi gas model reduction of mw with T  increase of Esymm Q-value of electron capture rates! increase of less neutronization  larger values of Yleptat trapping A. F. Fantina & P. Blottiau - CoCoNuT meeting 2009

  5. Ylept,tr Shock wave energy Shock wave loses energy while crossing matter. dissociation energy: Brown G. et al, Nucl. Phys. A375, 481 (1982) larger values of Yleptat trapping  less deleptonization  less energy dissipated Stronger shock wave explosion m*(T)Esym Yl,tr Shock wave energy A. F. Fantina & P. Blottiau - CoCoNuT meeting 2009

  6. Physical model – 1D Newtonian • 1D code Newtonian ( Blottiau P., PhD thesis (1989) & Ph. Mellor ) • - sphere divided in 40 zone for core, total 100 zone • - Lagrangian treatment, implicit scheme • Matter made up by: • - nuclei (A, Z), neutrons and free protons (classical e non relativistic) • - electrons and neutrinos (degenerate and ultra relativistic) •  EoS BBAL ( Bethe H.A. et al., Nucl. Phys.A324, 487 (1979) ) • Fuller ( Fuller G.M., Astrophys. J.252, 741 (1982) ) • + increasing of  to simulate stiffness of EoS • Hydro equation coupled to equation for electron fraction evolution • and capture • Neutrino transport: multigroup, flux limited scheme, • inclusion of different Np * Nh • ( Bruenn S., Astrophys. J. Suppl. 58, 771 (1985) ) • Trapping comes out “automatically” A. F. Fantina & P. Blottiau - CoCoNuT meeting 2009

  7. Preliminary results of collapse simulation at trapping density (1D Newtonian code) Bruenn S.W. 1985 Langanke K. et al. 2001 Bruenn S.W., Astrophys. J. Suppl. 58, 771 (1985) Langanke K. et al., Phys. Rev. C66, 45802 (2001) Impact of e- capture Impact of m*(T) A. F. Fantina & P. Blottiau - CoCoNuT meeting 2009

  8. Preliminary results of collapse simulation at bounce (1D Newtonian code) Impact of m*(T) Bruenn S.W. 1985 Langanke K. et al. 2001 Bruenn S.W., Astrophys. J. Suppl. 58, 771 (1985) Impact of e- capture Langanke K. et al., Phys. Rev. C66, 45802 (2001) A. F. Fantina & P. Blottiau - CoCoNuT meeting 2009

  9. Conclusions • Influence of T-dependence of Esym on the evolution of collapse • → systematic reduction of neutronization of the core • (increasing of final lepton fraction) & less energy dissipated by shock wave • - one zone model - • → position of shock wave formation: bigger homologous core • - 1D Newtonian code - • Gain in shock wave dissociation energy if we consider m*(T) : • dT Ediss~ 0.4 foe (estimation with one-zone code, • within reasonable physical ranges of parameters) • and: K~ 1 – 1.5 foe (Bethe H.A. & Pizzochero P., Astrophys. J. 350, L33 (1990)) •  even if no dramatic effect on dynamics of the collapse is expected • (see fluid instabilities, SASI, magnetic field, …) • effects are not negligible! A. F. Fantina & P. Blottiau - CoCoNuT meeting 2009

  10. Outlook • Nuclear point of view: Microscopic calculation of nuclear inputs • - Electron capture rates on nuclei • →2 • - Calculation of m*(T) & Esym(T): • → systematic calculations on more nuclei • → level density parameter (experiments?!) • → dependence on , A, Z, T • - EoS • → Lattimer & Swesty, Nucl. Phys. A535, 331 (1991), with IPN Orsay (E.Khan) N. Paar et al., submitted to Phys.Rev. C (2009) Milan & IPN Orsay (P.Donati & J.Margueron) • Astrophysical point of view: Hydrodynamics • - multizone / multi-D code → test in 1D • - Newtonian & Relativistic • - more accurate treatment of neutrinos • and shock formation CEA Bruyères (P.Blottiau & Ph. Mellor) & LUTH Meudon (J. Novak & M.Oertel) A. F. Fantina & P. Blottiau - CoCoNuT meeting 2009

  11. Thank you

  12. Physical model – one-zone • One-zone code • → collapse of sphere with uniform density  • Matter made up by: • - nuclei (A, Z), neutrons and free protons (C, NR) • - electrons and neutrinos (Q, UR) •  EoS BBP (Bethe et al., Nucl. Phys. A175, 225 (1971) ) • BBAL (Bethe et al., Nucl. Phys.A324, 487 (1979) ) • Thermal dissociation in  particle included (Saha eq.) • Entropy: translational (nuclei, protons and free neutrons), • excited states of nuclei, electrons and neutrinos (post trapping) • Electron capture on free+bound protons as 2-level transition at finite T • ( + backward reaction after trapping ), inclusion of 2 • Trapping as a discontinuity  Yn = 0 if r < rtr • ( after neutrino trapping  Ylept const! ) A. F. Fantina & P. Blottiau - CoCoNuT meeting 2009

  13. Numerical results of collapse simulation (one-zone code) g2 = 1 Langanke K. et al., Phys. Rev. Lett. 90, 241102 (2003) g2 = 0.1 Fuller G.M., Astroph. J. 252, 741 (1982) Fantina A.F. et al, Phys. Lett. B676, 140 (2009) A. F. Fantina & P. Blottiau - CoCoNuT meeting 2009

  14. Numerical results of collapse simulation (one-zone code) “Standard” parameters: Fantina A.F. et al, Phys. Lett. B676, 140 (2009) A. F. Fantina & P. Blottiau - CoCoNuT meeting 2009

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