A cosmological origin of GRBs leads to the conclusion of a huge energy output.
If the identification with the galaxy having redshift z=3.42 is true,
then in gamma radiation the energy release (without beaming) is
ergs
(Kulkarni 1998).
Note, that the
solar rest mass is equal to
ergs. Small timescale
indicates that GRBs are related to neutron
stars and (or) stellar mass black holes. The common event
from a collapse with a neutron star formation is a supernova explosion.
The total energy release
in a SN is equal to the
binding energy of a
neutron star
. For the neutron star with a mass
we get
ergs, which is
comparable to the above estimate for a GRB. Only a small
part
ergs is transformed into
kinetic energy of the explosion, and the energy radiated in all parts of the
electromagnetic spectrum is several tens times less. More then
of the total energy output is emitted in the form of weakly interacting
neutrinos, and is dispersed in the Universe.
An artificially constructed
low-temperature structure around a neutron star or a black
hole may suffer from an instability. Stars with a neutron core
(Thorne-Zytkov model) are in most cases unstable to run-away neutrino
emission, leading to radiation by neutrinos of
more then
of the accretion energy.
Magnetorotational explosion, used by
Pazcynski (1998)
to explain the
huge energy production in a cosmological GRB, had been suggested
for the supernova explosion by
Bisnovatyi-Kogan (1971).
Numerical 1-D
and 2-D calculations gave the efficiency of a
transformation of the rotational energy into the kinetic one at the
level of few percent
(Ardelyan et al. 1997).
The restrictions of the
"hypernova" model of
Pazcynski (1998)
had been analyzed by
Blinnikov & Postnov (1998).
The total
explosive energy output at the end of
the evolution of a close binary, consisting
of two neutron stars, suggested for a GRB model by
Blinnikov at al. (1984)
cannot exceed the value of a (positive) binding energy less than
ergs
(Saakyan & Vartanyan 1964).
Only part of this energy may be radiated in the GRB region.
In the presence of serious energy problems inherent in the model of
the cosmological GRB, we try to explain the pioneering
results of the afterglow measurements by Beppo-Sax, as
well as previous hard gamma-ray afterglow observed by EGRET, in the
frame of the model of GRB origin in the old nearby neutron stars
inside the Galactic disk. The host galaxies with a high redshift are supposed
to be a chance coincidence with GRB. Isotropy on the sky and non 3/2
may be connected with selection effects
(Bisnovatyi-Kogan 1997),
or a local non-uniformity
(B.V. Komberg, priv. comm.).
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