Aims. We have observed two newly detected gamma-ray pulsars, PSR J1459-6053 and PSR J1614-2230, in the X-ray domain with XMM-Newton to try to enlarge the sample of pulsars for which multi-wavelength data exist. We use these data with the aim of understanding the pulsar emission mechanisms of these pulsars. Methods. We analysed the X-ray spectra to determine whether the emission emanates from the neutron star surface (thermal emission) or from the magnetosphere (non-thermal emission) and compared this to the region in the magnetosphere in which the gamma-ray emission is generated. Furthermore, we compared the phase-folded X-ray lightcurves with those in the gamma-ray and, where possible, radio domains, to elicit additional information on the emission sites. Results. J1459-6053 shows X-ray spectra that are best fitted with a power law model with a photon index Gamma = 2.10(-0.85)(+1.24). The gamma-ray data suggest that either the slot gap or the outer gap model may be best to describe the emission from this pulsar. Analysis of the X-ray lightcurve folded on the gamma-ray ephemeris shows modulation at the 3.7 sigma level in the 1.0-4.5 keV domain. Possible alignment of the main gamma-ray and X-ray peaks also supports the interpretation that the emission in the two energy domains emanates from similar regions. The millisecond pulsar J1614-2230 exhibits an X-ray spectrum with a substantial thermal component, where the best-fitting spectral model is either two blackbodies, with kT = 0.15(-0.04)(+0.04) and 0.88(-0.54)(+2.54) keV or a blackbody with similar temperature to the previous cooler component, kT = 0.13(-0.02)(+0.04) keV and a power law component with a photon index Gamma = 1.25-(+2.30)(1.75). The cooler blackbody component is likely to originate from the hot surface at the polar cap. Analysis of the X-ray lightcurve folded on the radio ephemeris shows modulation at the 4.0 sigma level in the 0.4-3.0 keV domain.
NATURVETENSKAP -- Fysik -- Astronomi, astrofysik och kosmologi (hsv//swe)