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GRB PRODUCTION & SN SIGNATURES IN SLOWLY ROTATING COLLAPSARS.

GRB PRODUCTION & SN SIGNATURES IN SLOWLY ROTATING COLLAPSARS. NS & GRBs, Cairo & Alexandria, Egypt 3 rd of April, 2009. Diego Lopez-Camara Instituto de Astronom ía (UNAM), Mexico City. In collaboration with William Lee & Enrico Ramirez-Ruiz. (Lopez-Camara et al., 2009 ApJ).

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GRB PRODUCTION & SN SIGNATURES IN SLOWLY ROTATING COLLAPSARS.

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  1. GRB PRODUCTION & SN SIGNATURES IN SLOWLY ROTATING COLLAPSARS. NS & GRBs, Cairo & Alexandria, Egypt 3rd of April, 2009. Diego Lopez-Camara Instituto de Astronomía (UNAM), Mexico City. In collaboration with William Lee & Enrico Ramirez-Ruiz (Lopez-Camara et al., 2009 ApJ)

  2. GRB characteristics… GRB SN connection: • GRB980425 con SN1998bw (Galama et al., 1998) • XRF020903 (Soderberg et al., 2004) • GRB021211 con SN2002lt (Della Valle et al., 2003) • GRB030329 con SN2003dh (Stanek et al., 2003) • GRB031203 con SN2003lw(Malesani et al.,2004) • GRB050525A con SN2005nc(Della Valle et al., 2006a) • GRB060218 con SN2006aj (Campana et al., 2006). LGRBs Cosmological distances (Metzger, 1997)  COLLAPSAR LLGRB ≈ 1049 erg s-1 - 1052 erg s-1 1 / 11

  3. If J < Jcrit quasi-radial acretion onto the CO • If J ≥ Jcrit accretion disk is formed. …Accretion Jcrit = 2 rs c ~ 1016 cm2 s-1 (for a 1 MO BH) Previous studies have assumed J << Jcritor J >> Jcrit J ≈ Jcrit requires further investigation. 2 / 11

  4. t = 0 t > 0 ? ? ? Rout Rout BH ? ? T(R) = Tcollapsar T(R) = ? ? ? ? W VR(R) = Vcollapsar VR(R) = ? r rcollapsar (R) = r (R) = ? J(R) = J(R)collapsar J(R) = ? more… Objective: To study the evolution, morphology, and energy output within the collapsar scenario using the best physics possible, in the J ≈ Jcrit limit. Mdot(t) = ? L(t) = ? BH Initial conditions: Woosley & Heger’s (2006) 1D pre-SN 16TI model for a rapidly rotating, 16MO WR star of low metallicity. 3 / 11

  5. J(R) (cm2 s-1) J(R) (cm2 s-1) J(R) ≥ Jcrit J(R) < Jcrit J(R) > Jcrit J(R) ≈< Jcrit R (cm) R (cm) In order to understand the J effects… J(R,) = J(R) J() = J(R) sin2  Stellar rotation rate in pre-SN cores is not fully determined. It is important to determine under which conditions the progenitor can produce a LGRB. 4 / 11

  6. 1.8x108 1.4x108 1.0x108 0.6x108 0.2x108 1.2x109 1.0x109 0.8x109 0.6x109 0.4x109 0.2x109 Results… t = 0.2 s  = 0.1 J(R) ≈< Jcrit J(R) ≥ Jcrit v  v  vmax= 8 x107 cm s-1 5 / 11

  7. J(R) ≈< Jcrit J(R) ≥ Jcrit Equatorial profiles: t = 0.2 s  = 0.1 Clear difference between both regimes!!! 6 / 11

  8. ann    . ann disp q  cap  . cap q Equatorial profiles: t = 0.2 s  = 0.1 Energy emission? 7 / 11

  9. How efficient was the neutrino cooling? t = 0.2 s  = 0.1 J(R) ≥ Jcrit more… Isothermal Adiabatic 8 / 11

  10. Luminosity…  = 0.1 1053 J(R) ≥ Jcrit 1052 J(R) ≈< Jcrit 1051 1050 t(s) 0.40 0.30 0.35 0.00 0.05 0.10 0.15 0.20 0.25  Lgrb 1049 erg s-1 J ≥ Jcrit L 1052 erg s-1 • = 0.1% for    e-e+ (Birkl et al., 2007) J ≈< Jcrit L 1051 erg s-1 Lgrb 1048 erg s-1 9 / 11

  11. GRB - SN t = 0.2 s J(R) ≈< Jcrit J(R) ≥ Jcrit  = 0.1  Winds expected in collapsar disks = viscous +  + B(MacFadyen & Woosley, 1999) We inferred the expectednucleosynthesis of56Niin the wind outflows (Pruet et al., 2004) J(R) ≥ Jcrit substantial 56Ni synthesis. (1MO of 56Ni in 10s) GRB + SN J(R) ≈< Jcrit no56Ni synthesis. GRB w/o SN (GRB060505 ?) 10 / 11

  12. Conclusions • Clear difference between J ≥ Jcritand J < Jcrit. • Flow properties lie between the isothermal and adiabatic regimes. • Good thermodynamics and neutrino treatment are necessary. • Even J ≈< Jcrit could power a low energetic GRB. • GRB SN connection… • J(R) ≥ Jcrit  GRB + SN. • J(R) ≈< Jcrit  GRB w/o SN 11 / 11

  13. The end

  14. Isothermal Our case Adiabatic even more… J ~ Jcritis between the two regimes! (thus cooling can not be ignored) back…

  15. …how efficient was the cooling? back… tcool / tdyn tcool >> tdyn  cooling is inefficient. (but necesary)

  16. “Best physics”… back… Good EOS Neutrino optical depth () “two stream approximation”. Neutrino cooling and heating. Variable electronic fraction (Ye). Self gravity (assuming sherical symetry). Turbulent viscosityShakura & Sunyaev´s recipe (1973). Relativistic effects Paczynski & Wiita´spotential (1980). EOS…

  17. …EOS back… ideal gas of α + free nucleons (NSE) blackbody radiation (fully trapped) neutrino radiation relativistic e pairs (arbitrary degeneracy) cap  qcap(Langanke & Martinez-Pinedo, 2001) ann  qann(Itoh et al., 1996) ann  Shapiro & Teukolski (1983)

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