Phase resolved spectroscopy of the Vela pulsar with XMM-Newton

Abstract

The ~10^4 y old Vela Pulsar represents the bridge between the young Crab-like and the middle-aged rotation powered pulsars. Its multiwavelength behaviour is due to the superposition of different spectral components. We take advantage of the unprecedented harvest of photons collected by XMM-Newton to assess the Vela Pulsar spectral shape and to study the pulsar spectrum as a function of its rotational phase. As for the middle-aged pulsars Geminga, PSR B0656+14 and PSR B1055-52 (the "Three Musketeers"), the phase-integrated spectrum of Vela is well described by a three-component model, consisting of two blackbodies (T_bb1=(1.06+/-0.03)x10^6 K, R_bb1=5.1+/-0.3 km, T_bb2=(2.16+/-0.06)x10^6 K, R_bb2=0.73+/-0.08 km) plus a power-law (gamma=2.2+/-0.3). The relative contributions of the three components are seen to vary as a function of the pulsar rotational phase. The two blackbodies have a shallow 7-9% modulation. The cooler blackbody, possibly related to the bulk of the neutron star surface, has a complex modulation, with two peaks per period, separated by ~0.35 in phase, the radio pulse occurring exactly in between. The hotter blackbody, possibly originating from a hot polar region, has a nearly sinusoidal modulation, with a single, broad maximum aligned with the second peak of the cooler blackbody, trailing the radio pulse by ~0.15 in phase. The non thermal component, magnetospheric in origin, is present only during 20% of the pulsar phase and appears to be opposite to the radio pulse. XMM-Newton phase-resolved spectroscopy unveils the link between the thermally emitting surface of the neutron star and its charge-filled magnetosphere, probing emission geometry as a function of the pulsar rotation. This is a fundamental piece of information for future 3-dimensional modeling of the pulsar magnetosphere.

arXiv comment27 pages, 9 figures. Accepted for publication in ApJ

References in corpus (19)

• An Overview of the Performance and Scientific Results from the Chandra X-Ray Observatory (CXO)
• The 2-8 keV cosmic X-ray background spectrum as observed with XMM-Newton
• $\gamma$-Ray Pulsars: Emission Zones and Viewing Geometries
• The Vela Pulsar and its Synchrotron Nebula
• Two-Pole Caustic Model for High-Energy Lightcurves of Pulsars
• The Vela Pulsar's proper motion and parallax derived from VLBI observations
• Pulsar Polar Cap Heating and Surface Thermal X-Ray Emission II. Inverse Compton Radiation Pair Fronts
• The X-ray Spectrum of the Vela Pulsar Resolved with Chandra
• The Variable Jet of the Vela Pulsar
• On the polar caps of the 3 Musketeers
• Surface Temperature of a Magnetized Neutron Star and Interpretation of the ROSAT Data. I. Dipolar Fields
• Variability of the Vela Pulsar-wind Nebula Observed with Chandra
• The distance to the Vela pulsar gauged with HST parallax oservations
• Confronting Neutron Star Cooling Theories with New Observations
• The Multi-Component Nature of the Vela Pulsar Nonthermal X-ray Spectrum
• Phase-resolved spectroscopy of Geminga shows rotating hot spot(s)
• The Vela Pulsar in the Ultraviolet
• XMM-Newton observations of the Vela pulsar
• Low-Energy X-ray Emission from Young Isolated Neutron Stars

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• XMM-Newton X-ray Detection of the High Magnetic Field Radio Pulsar PSR B1916+14
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• The Vela Pulsar With an Active Fallback Disk
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• Timing analysis and pulse profile of the Vela pulsar in the optical band from Iqueye observations
• The gamma-ray spectrum of Geminga and the inverse Compton model of pulsar high energy emission
• The r-mode instability windows of strange stars
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