A solution to the sigma problem - that of finding a mechanism capable of
converting Poynting energy flux to particle-borne energy flux in a pulsar wind
- was proposed several years ago by Coroniti and Michel who considered a
particular prescription for magnetic reconnection in a striped wind. This
prescription was later shown to be ineffective. In this paper, we discuss the
basic microphysics of the reconnection process and conclude that a more rapid
prescription is permissible. Assuming dissipation to set in at some distance
outside the light-cylinder, we compute the resulting radiation signature and
find that the synchrotron emission of heated particles appears periodic, in
general showing both a pulse and an interpulse. The predicted spacing of these
agrees well with observation in the case of the Crab and Vela pulsars. Using
parameters appropriate for the Crab pulsar - magnetization parameter at the
light cylinder sigma_L = 6 x 10^4, Lorentz factor Gamma=250 - reasonable
agreement is found with the observed total pulsed luminosity. This suggest that
the high-energy pulses from young pulsars originate not in the co-rotating
magnetosphere within the light cylinder (as in all other models) but from the
radially directed wind well outside it.Comment: 6 pages, 2 figures. To appear in the Proceedings of the 270.
WE-Heraeus Seminar on Neutron Stars, Pulsars and Supernova Remnants, Jan.
21-25, 2002, Physikzentrum Bad Honnef, eds W. Becker, H. Lesch & J. Truemper.
Proceedings are available as MPE-Report 27
