Chandra observations of the high-magnetic-field radio pulsar j1718-3718

Abstract

High-magnetic-field pulsars represent an important class of objects for studying the relationship between magnetars and radio pulsars. Here we report on four Chandra observations of the high-magnetic-field pulsar J1718-3718 (B = 7.4 × 10 13G) taken in 2009 as well as a reanalysis of 2002 Chandra observations of the region. We also report an improved radio position for this pulsar based on ATCA observations. We detect X-ray pulsations at the pulsar's period in the 2009 data, with a pulsed fraction of 52% ± 13% in the 0.8-2.0keV band. We find that the X-ray pulse is aligned with the radio pulse. The data from 2002 and 2009 show consistent spectra and fluxes: a merged overall spectrum is well fit by a blackbody of temperature 186 +19 - 18eV, slightly higher than predicted by standard cooling models; however, the best-fit neutron star atmosphere model is consistent with standard cooling. We find the bolometric luminosity L ∞ bb = 4 +5 - 2 × 10 32ergs -1 for a distance of 4.5kpc. We compile measurements of the temperatures of all X-ray-detected high-B pulsars as well as those of low-B radio pulsars and find evidence for the former being hotter on average than the latter. © 2011. The American Astronomical Society. All rights reserved.