  Millisecond pulsar PSR J0218+4232 shows remarkable high-energy properties:
very hard pulsed X-ray emission up to ~10 keV and a likely detection of
high-energy gamma-rays (> 100 MeV) with a soft spectrum. The relative phasing
of the X-ray and gamma-ray profiles, however, was unknown. A recently performed
Chandra (0.08-10 keV) observation of PSR J0218+4232 settled the phasing down to
0.2 millisecond, and shows that the X-ray pulses are aligned with the gamma-ray
pulses providing supporting evidence for our first detection of high-energy
gamma-rays from this source. The preliminary results from a recent RXTE (2-250
keV) observation (27-12-2001 -- 7-01-2002) show significant pulsed emission, in
a complex profile, up to ~20 keV. The composite high-energy spectrum of this
millisecond pulsar is similar to the canonical spectrum of Unidentified
Gamma-ray Sources (UGS), making fast (<3-4 ms) millisecond pulsars with low
characteristic ages (<10^8 years) good candidates for an UGS association and
challenging targets for INTEGRAL observations.
