Presentation on theme: "GRB PRODUCTION & SN SIGNATURES IN SLOWLY ROTATING COLLAPSARS. Diego Lopez-Camara Instituto de Astronomía (UNAM), Mexico City. In collaboration with William."— Presentation transcript:
GRB PRODUCTION & SN SIGNATURES IN SLOWLY ROTATING COLLAPSARS. Diego Lopez-Camara Instituto de Astronomía (UNAM), Mexico City. In collaboration with William Lee & Enrico Ramirez-Ruiz (Lopez-Camara et al., 2009 ApJ) NS & GRBs, Cairo & Alexandria, Egypt 3 rd of April, 2009.
GRB characteristics… Cosmological distances (Metzger, 1997) L LGRB ≈ erg s erg s -1 GRB SN connection: 1.GRB con SN1998bw (Galama et al., 1998) 2.XRF (Soderberg et al., 2004) 3.GRB con SN2002lt (Della Valle et al., 2003) 4.GRB con SN2003dh (Stanek et al., 2003) 5.GRB con SN2003lw (Malesani et al.,2004) 6.GRB050525A con SN2005nc (Della Valle et al., 2006a) 7.GRB con SN2006aj (Campana et al., 2006). COLLAPSAR COLLAPSAR 1 / 11 LGRBs
If J < J crit quasi-radial acretion onto the CO J crit = 2 r s c ~ cm 2 s -1 (for a 1 M O BH) ≈ J ≈ J crit requires further investigation. Previous studies have assumed J > J crit If J ≥ J crit accretion disk is formed.…Accretion 2 / 11
t = 0 Rout V R (R) = V collapsar (R) = collapsar T(R) = T collapsar J(R) = J(R) collapsar BH M dot (t) = ? V R (R) = ? (R) = ? T(R) = ? J(R) = ? t > 0 ? ? ? ? ? ? ? ? Rout BH L(t) = ? ≈ Objective: To study the evolution, morphology, and energy output within the collapsar scenario using the best physics possible, in the J ≈ J crit limit. Initial conditions: Woosley & Heger’s (2006) 1D pre-SN 16TI model for a rapidly rotating, 16M O WR star of low metallicity. 3 / 11 more…
In order to understand the J effects… J(R, ) = J(R) J( ) = J(R) sin 2 4 / 11 J(R) (cm 2 s -1 ) J(R) ≥ J crit J(R) < J crit R (cm) J(R) (cm 2 s -1 ) J(R) > J crit J(R) ≈< J crit R (cm) 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.
t = 0.2 s v max = 8 x10 7 cm s -1 J(R) ≈< J crit v 1.8x x x x x x x x x x x10 9v Results… 5 / 11 J(R) ≥ J crit = 0.1
J(R) ≥ J crit J(R) ≈< J crit Clear difference between both regimes!!! 6 / 11 t = 0.2 s = 0.1 Equatorial profiles:
q q .. cap ann disp ann cap t = 0.2 s = / 11 Energy emission? Equatorial profiles:
IsothermalAdiabatic How efficient was the neutrino cooling? 8 / 11 t = 0.2 s = 0.1 J(R) ≥ J crit more…
Luminosity… = 0.1 ≈< J ≈< J crit L erg s -1 L grb erg s -1 J ≥ J crit L erg s -1 L grb erg s -1 = 0.1% for e - e + (Birkl et al., 2007) t(s) / 11 J(R) ≈< J crit J(R) ≥ J crit
t = 0.2 s GRB - SN J(R) ≥ J crit = 0.1 Winds expected in collapsar disks = viscous + + B (MacFadyen & Woosley, 1999) We inferred the expected nucleosynthesis of 56 Ni in the wind outﬂows (Pruet et al., 2004) J(R) ≈< J crit J(R) ≥ J crit substantial 56 Ni synthesis. (1M O of 56 Ni in 10s) GRB + SN J(R) ≈< J crit J(R) ≈< J crit no 56 Ni synthesis. GRB w/o SN (GRB ?) 10 / 11
Conclusions 1.Clear difference between J ≥ J crit and J < J crit. 2.Flow properties lie between the isothermal and adiabatic regimes. 3.Good thermodynamics and neutrino treatment are necessary. 4.Even J ≈< J crit could power a low energetic GRB. 5.GRB SN connection… J(R) ≥ J crit GRB + SN. J(R) ≈< J crit GRB w/o SN 11 / 11
is between the two regimes! J ~ J crit is between the two regimes! (thus cooling can not be ignored) (thus cooling can not be ignored) Adiabatic Isothermal Our case back… even more…
t cool / t dyn t cool >> t dyn cooling is inefficient. (but necesary) …how efficient was the cooling? back…