Deep XMM-newton spectroscopic and timing observations of the isolated radio millisecond pulsar PSR J0030+0451

Abstract

We present deep XMM-Newton European Photon Imaging Camera spectroscopic and timing X-ray observations of the nearby solitary radio millisecond pulsar, PSRJ0030+0451. Its emission spectrum in the 0.1-10keV range is found to be remarkably similar to that of the nearest and best-studied millisecond pulsar, PSRJ0437-4715, being well described by a predominantly thermal two-temperature model plus a faint hard tail evident above 2keV. The pulsed emission in the 0.3-2keV band is characterized by two broad pulses with pulsed fraction 60%-70%, consistent with a mostly thermal origin of the X-rays only if the surface polar cap radiation is from a light-element atmosphere. Modeling of the thermal pulses permits us to place constraints on the neutron star radius of R > 10.7 (95% confidence) and R > 10.4km (at 99.9% confidence) for M = 1.4 M ̊. © 2009. The American Astronomical Society. All rights reserved.