INVESTIGADORES
MOLLERACH Maria Silvia
artículos
Título:
Decaying neutron propagation in the galaxy and the cosmic ray anisotropy at 1EeV
Autor/es:
M. BOSSA, S. MOLLERACH Y E. ROULET
Revista:
JOURNAL OF PHYSICS G-NUCLEAR AND PARTICLE PHYSICS
Editorial:
IOP
Referencias:
Año: 2003 vol. 29 p. 1409 - 1421
ISSN:
0954-3899
Resumen:
We study the cosmic ray arrival distribution expected from a source of
neutrons in the galactic center at energies around 1 EeV and compare it with
the anisotropy detected by AGASA and SUGAR. Besides the point-like signal in
the source direction produced by the direct neutrons, an extended signal due to
the protons produced in neutron decays is expected. This associated proton
signal also leads to an excess in the direction of the spiral arm. For
realistic models of the regular and random galactic magnetic fields, the
resulting anisotropy as a function of the energy is obtained. We find that for
the anisotropy to become sufficiently suppressed below E\sim 10^{17.9}eV, a
significant random magnetic field component is required, while on the other
hand, this also tends to increase the angular spread of the associated proton
signal and to reduce the excess in the spiral arm direction. The source
luminosity required in order that the right ascension anisotropy be 4% for the
AGASA angular exposure corresponds to a prediction for the point-like flux from
direct neutrons compatible with the flux detected by SUGAR. We also analyse the
distinguishing features predicted for a large statistics southern observatory.