The recent discovery of a magnetar in the Galactic centre region has allowed
Spitler et al. to characterize the interstellar scattering in that direction.
They find that the temporal broadening of the pulse profile of the magnetar is
substantially less than that predicted by models of the electron density of
that region. This raises the question of what the plausible limits for the
number of potentially observable pulsars - i.e., the number of pulsars beaming
towards the Earth - in the Galactic centre are. In this paper, using reasonable
assumptions - namely, (i) the luminosity function of pulsars in the Galactic
centre region is the same as that in the field, (ii) the region has had a
constant pulsar formation rate, (iii) the spin and luminosity evolution of
magnetars and pulsars are similar, and (iv) the scattering in the direction of
the Galactic centre magnetar is representative of the entire inner parsec - we
show that the potentially observable population of pulsars in the inner parsec
has a conservative upper limit of ∼ 200, and that it is premature to
conclude that the number of pulsars in this region is small. We also show that
the observational results so far are consistent with this number and make
predictions for future radio pulsar surveys of the Galactic centre.Comment: 5 pages, 3 figures, Accepted for publication in MNRAS Letter
