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X-ray Spectrum and Pulsations of the Vela Pulsar

D. Sanwal·G. G. Pavlov·O. Y. Kargaltsev·G. P. Garmire·V. E. Zavlin·V. Burwitz·R. N. Manchester·R. Dodson
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Abstract

We report the results of the spectral and timing analysis of observations of the Vela pulsar with the Chandra X-ray Observatory. The spectrum shows no statistically significant spectral lines in the observed 0.25--8.0 keV band. It consists of two distinct continuum components. The softer component can be modeled as either a magnetic hydrogen atmosphere spectrum with kT = 59 +- 3 eV, R = 15.5 +- 1.5 km, or a standard blackbody with kT = 129 +- 4 eV, R = 2.1 +- 0.2 km (the radii are for a distance of 250 pc). The harder component, modeled as a power-law spectrum, gives photon indices depending on the model adopted for the soft component: gamma = 1.5 +- 0.3 for the magnetic atmosphere soft component, and gamma = 2.7 +- 0.4 for the blackbody soft component. Timing analysis shows three peaks in the pulse profile, separated by about 0.3 in phase. Energy-resolved timing provides evidence for pulse profile variation with energy. The higher energy (E > 1.8 keV) profile shows significantly higher pulsed fraction.

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D. Sanwal, G. G. Pavlov, O. Y. Kargaltsev, G. P. Garmire, V. E. Zavlin, V. Burwitz, R. N. Manchester, R. Dodson. 2001-12-12. X-ray Spectrum and Pulsations of the Vela Pulsar. https://arxiv.org/abs/astro-ph/0112164

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