Pulsar Population Synthesis with Magnetorotational Evolution: Constraining the Decay of Magnetic field

We present a population synthesis model for normal radio pulsars in the Galaxy incorporating the latest developments in the field and the magnetorotational evolution processes.

Our model considers spin-down with a force-free magnetosphere and the decay of the magnetic field strength and its inclination angle.

The simulated pulsar population is fit to a large observation sample that covers the majority of radio surveys using the Markov Chain Monte Carlo technique.

We compare the distributions of four major observables: spin period (P), spin down rate($\dot{P}$), dispersion measure, and radio flux density using accurate high-dimensional Kolmogoro-Smirnov statistics.

We test two B-field decay scenarios, an exponential model motivated by ohmic dissipation and a power-law model motivated by the Hall effect.

The former clearly provides a better fit, and it can successfully reproduce the observed pulsar distributions with a decay timescale of $8.3_{-3.0}^{+3.9}$ Myr.

The result suggests that significant B-field decay in aged pulsars and ohmic dissipation could be the dominant process.

;Comment: 17 pages, 10 figures.

Published by APJ.

A little mistake was found in Fig 7's x-axis in the published APJ version, we changed that in this version