  Previous work on the emission from isolated old neutron stars (IONS)
accreting the inter-stellar medium (ISM) focussed on gravitational capture -
Bondi accretion. We propose a new class of sources which accrete via magnetic
interaction with the ISM. While for the Bondi mechanism, the accretion rate
decreases with increasing NS velocity, in magnetic accretors (MAGACs="magics")
the accretion rate increases with increasing NS velocity. MAGACs will be
produced among high velocity (~> 100 km s-1) high magnetic field (B> 1e14 G)
radio pulsars - the ``magnetars'' - after they have evolved first through
magnetic dipole spin-down, followed by a ``propeller'' phase (when the object
sheds angular momentum on a timescale ~< 1e10 yr). The properties of MAGACS may
be summarized thus: dipole magnetic fields of B~>1e14 G; minimum velocities
relative to the ISM of >25-100 km s-1, depending on B, well below the median in
the observed radio-pulsar population; spin-periods of >days to years; accretion
luminosities of 1e28- 1e31 ergs s-1 ; and effective temperatures kT=0.3 - 2.5
keV if they accrete onto the magnetic polar cap. We find no examples of MAGACs
among previously observed source classes (anomalous X-ray pulsars,
soft-gamma-ray repeaters or known IONS). However, MAGACs may be more prevelant
in flux-limited X-ray catalogs than their gravitationally accreting
counterparts.
