Pulsar Population Synthesis with Magnetorotational Evolution: Constraining the Decay of the Magnetic Field
Year: 2024
Type: article
Abstract: 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 ( P ̇ ), dispersion measure, and radio flux density—using accurate high-dimensional Kolmogorov–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.
Source: The Astrophysical Journal
Authors: Zhihong Shi, C.-Y. Ng
Institution: University of Hong Kong
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $4,499
Funder: Hong Kong Government
Award: G5391528681
OpenAlex ID: W4401882882