GRB PRODUCTION & SN SIGNATURES IN SLOWLY ROTATING
COLLAPSARS. Diego Lopez-Camara Instituto de Astronoma (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. Slide 2 GRB
characteristics Cosmological distances (Metzger, 1997) L LGRB 10 49
erg s -1 - 10 52 erg s -1 GRB SN connection: 1.GRB980425 con
SN1998bw (Galama et al., 1998) 2.XRF020903 (Soderberg et al., 2004)
3.GRB021211 con SN2002lt (Della Valle et al., 2003) 4.GRB030329 con
SN2003dh (Stanek et al., 2003) 5.GRB031203 con SN2003lw (Malesani
et al.,2004) 6.GRB050525A con SN2005nc (Della Valle et al., 2006a)
7.GRB060218 con SN2006aj (Campana et al., 2006). COLLAPSAR
COLLAPSAR 1 / 11 LGRBs Slide 3 If J < J crit quasi-radial
acretion onto the CO J crit = 2 r s c ~ 10 16 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 Slide 4 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 & Hegers (2006) 1D pre-SN 16TI model for a rapidly
rotating, 16M O WR star of low metallicity. 3 / 11 more Slide 5 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.
Slide 6 t = 0.2 s v max = 8 x10 7 cm s -1 J(R) < J crit v 1.8x10
8 1.4x10 8 1.0x10 8 0.6x10 8 0.2x10 8 1.2x10 9 1.0x10 9 0.8x10 9
0.6x10 9 0.4x10 9 0.2x10 9v Results 5 / 11 J(R) J crit = 0.1 Slide
7 J(R) J crit J(R) < J crit Clear difference between both
regimes!!! 6 / 11 t = 0.2 s = 0.1 Equatorial profiles: Slide 8 q q
.. cap ann disp ann cap t = 0.2 s = 0.1 7 / 11 Energy emission?
Equatorial profiles: Slide 9 IsothermalAdiabatic How efficient was
the neutrino cooling? 8 / 11 t = 0.2 s = 0.1 J(R) J crit more Slide
10 Luminosity = 0.1 < J < J crit L 10 51 erg s -1 L grb 10 48
erg s -1 J J crit L 10 52 erg s -1 L grb 10 49 erg s -1 = 0.1% for
e - e + (Birkl et al., 2007) 10 52 10 53 10 51 10 50 t(s) 0.00
0.100.15 0.200.25 0.300.35 0.40 0.05 9 / 11 J(R) < J crit J(R) J
crit Slide 11 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
outows (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
(GRB060505 ?) 10 / 11 Slide 12 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 Slide 13 Slide 14 The end Slide 15
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 Slide 16 t cool / t
dyn t cool >> t dyn cooling is inefficient. (but necesary)
how efficient was the cooling? back Slide 17 Best physics Good EOS
Neutrino optical depth ( ) two stream approximation. Neutrino
cooling and heating. Variable electronic fraction (Y e ). Self
gravity (assuming sherical symetry). Turbulent viscosity Shakura
& Sunyaevs recipe (1973). Relativistic effects Paczynski &
Wiitas potential (1980). backEOS Slide 18 EOS ideal gas of + free
nucleons (NSE) blackbody radiation (fully trapped) neutrino
radiation relativistic e pairs (arbitrary degeneracy) cap q cap (
Langanke & Martinez-Pinedo, 2001) ann q ann ( Itoh et al.,
1996) ann Shapiro & Teukolski (1983)
