Imprint of magnetic obliquity in apparent spin-down of radio pulsars

Abstract

Numerical simulations predict that the spin-down rate of a single rotation-powered neutron star depends on the angle $\alpha$ between its spin and magnetic axes as $P\dot{P}\propto {\mu }^2(k_0+k_1{\sin }^2\alpha )$, where $P$ is the star spin period, $\mu$ is its magnetic moment, while $k_0\sim k_1\sim 1$. Here we describe a simple observational test for this prediction based on the comparison of spin-down rates of 50 nearly orthogonal (with $\alpha$ close to 90 deg) and 27 nearly aligned (with $\alpha$ close to 0 deg) pulsars. We found, that the apparent pulsar spin-down is consistent with the theory if assumed, that magnetic moments of orthogonal rotators are systematically larger than those of aligned ones for $\sim \mathrm{0.15..0.2}$ dex. Also, as a by-product of the analysis, we provide yet another constraint on the average braking index of radio pulsars as $1\le n\le 4$ with formal significance not worse than 99\%.

arXiv commentMNRAS accepted

References in corpus (21)

• The ATNF Pulsar Catalogue
• Masses, Radii, and Equation of State of Neutron Stars
• Time-dependent force-free pulsar magnetospheres: axisymmetric and oblique rotators
• Birth and Evolution of Isolated Radio Pulsars
• Unifying the observational diversity of isolated neutron stars via magneto-thermal evolution models
• Models of Pulsar Glitches
• An analysis of the timing irregularities for 366 pulsars
• Time evolution of pulsar obliquity angle from 3D simulations of magnetospheres
• Population synthesis studies of isolated neutron stars with magnetic field decay
• A High Braking Index for a Pulsar
• Population synthesis of isolated Neutron Stars with magneto--rotational evolution
• The population of pulsars with interpulses and the implications for beam evolution
• Observations and Modelling of Relativistic Spin Precession in PSR J1141-6545
• On the beam properties of radio pulsars with interpulse emission
• Isolated pulsar spin evolution on the P-Pdot Diagram
• On the pulse--width statistics in radio pulsars. I. Importance of the interpulse emission
• Polarisation measurements of five pulsars with interpulses
• Monotonic and cyclic components of radio pulsars spin-down
• Modified pulsar current analysis: probing magnetic field evolution
• Orthogonal pulsars as a key test for pulsar evolution
• Refinement of the timing-based estimator of pulsar magnetic fields

Cited by in corpus (1)

• Evidence for the spin-kick alignment of pulsars from the statistics of their magnetic inclinations