  Periodic pulsations have been found in emission from the ultra-luminous X-ray
source (ULX) M82 X-2, strongly suggesting that the emitter is a rotating
neutron star rather than a black hole. However, the radiation mechanisms and
accretion mode involved have not yet been clearly established. In this paper,
we examine the applicability to this object of standard accretion modes for
high mass X-ray binaries (HMXBs). We find that spherical wind accretion, which
drives OB-type HMXBs, cannot apply here but that there is a natural explanation
in terms of an extension of the picture for standard Be-type HMXBs. We show
that a neutron star with a moderately strong magnetic field, accreting from a
disc-shaped wind emitted by a Be-companion, could be compatible with the
observed relation between spin and orbital period. A Roche lobe overflow
picture is also possible under certain conditions.
