X-ray follow-up observations of the two γ-ray pulsars PSR J1459–6053 and PSR J1614–2230
1 Université de Toulouse, UPS-OMP, IRAP, 31028 Toulouse, France
2 CNRS, IRAP, 9 avenue du Colonel Roche, BP 44346, 31028 Toulouse Cedex 4, France
3 Max-Planck Institute für extraterr. Physik, Giessenbachstrasse 1, 85741 Garching, Germany
4 Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, 53121 Bonn, Germany
5 Laboratoire de Physique et Chimie de l’Environnement et de l’Espace LPC2E CNRS-Université d’Orléans, 45071 Orléans Cedex 2, France
6 Station de radioastronomie de Nançay, Observatoire de Paris, CNRS/INSU, 18330 Nançay, France
7 Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, 53121 Bonn, Germany
8 School of Physics and Astronomy, University of Southampton, Highfield, Southampton SO17 1BJ, UK
9 Department of Physics, Royal Institute of Technology, AlbaNova, 10691 Stockholm, Sweden
10 The Oskar Klein Centre for Cosmoparticle Physics, AlbaNova, 10691 Stockholm, Sweden
11 Mullard Space Science Laboratory, University College London, Holmbury St. Mary, Dorking, Surrey, RH5 6NT, UK
12 Institute of Astronomy, University of Zielona Góra, Lubuska 2, 65-265 Zielona Góra, Poland
13 Institut de Ciencies de l’Espai (CSIC-IEEC), Campus UAB, Facultat de Ciencies, Torre C5-parell, 2a planta, 08193 Bellaterra (Barcelona), Spain
Received: 16 August 2011
Accepted: 28 April 2012
Aims. We have observed two newly detected γ-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 γ-ray emission is generated. Furthermore, we compared the phase-folded X-ray lightcurves with those in the γ-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 . The γ-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 γ-ray ephemeris shows modulation at the 3.7σ level in the 1.0−4.5 keV domain. Possible alignment of the main γ-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 and 0.88 keV or a blackbody with similar temperature to the previous cooler component, keV and a power law component with a photon index . 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 4.0σ level in the 0.4−3.0 keV domain.
Key words: X-rays: stars / pulsars: individual: PSR J1459 − 6053 / radiation mechanisms: thermal / stars: neutron / radiation mechanisms: non-thermal / pulsars: individual: PSR J1614 − 2230
© ESO, 2012