Abstract: Evolution of Globular Cluster Pulsars: Predictions
We have examined the possibility that rapid weakly magnetized pulsars might be
formed in Type II supernova such as SN1987A in the LMC.
Since these supernova are the expected progenitors
of the strongly magnetized galactic disc pulsars, it is then necessary to assume
that the magnetic field grows rapidly and saturates around 10^12 G.
Given that the Crab pulsar already has a strong field after 900 years, there is
only a short time in which to grow the field. We show that the fast pulsar
does not have time to spin down significantly during the growth period, with
the result that we will have for a time
a FAST strongly magnetized pulsar,
with a luminosity 1000 times that of the Crab pulsar.
This bright phase should last several hundred years, roughly the interval
between supernova, which raises observational questions of why they have not
yet been detected.
In any event, the luminosity should increase steadily,
about 2%/year or possibly more in an exponential
increase model, and a whopping 38%/year in a linear increase model.
Why the "millisecond" pulsars themselves do not experience such a run up of
magnetic field is an open question.
It is potentially interesting, however, that the time to reach saturation is
of the order of a few hundred years in both models.
Our overall conclusion is that a rapid weakly magnetized pulsar in SN1987A
appears to be inconsistent with what is known about pulsars and supernova
remnants (SNR),
but is not entirely excluded.
Moreover a small but steady continued increase in pulsar magnetization would
account for the observations of braking indices less than 3 in all young
pulsars were it can be determined.