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Pulsar braking indices, glitches and energy dissipation in neutron stars

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2006-10-11
Alpar, M. Ali
Baykal, Altan
Almost all pulsars with anomalous positive Omega measurements (corresponding to anomalous braking indices in the range 5 <vertical bar n vertical bar < 100), including all the pulsars with observed large glitches (Delta Omega/Omega > 10(-7)) as well as post-glitch or interglitch Omega measurements, obey the scaling between Omega and glitch parameters originally noted in the Vela pulsar. Negative second derivative values can be understood in terms of glitches that were missed or remained unresolved. We discuss the glitch rates and a priori probabilities of positive and negative braking indices according to the model developed for the Vela pulsar. This behaviour supports the universal occurrence of a non- linear dynamical coupling between the neutron star crust and an interior superfluid component. The implied lower limit to dynamical energy dissipation in a neutron star with spindown rate (Omega) over bar (E) over bar (diss) > 1.7 x 10(-6) (E) over bar (rot). Thermal luminosities and surface temperatures due to dynamical energy dissipation are estimated for old neutron stars which are spinning down as rotating magnetic dipoles beyond the pulsar death line.