The evolution of the magnetic inclination angle as an explanation of the long term red timing-noise of pulsars

Abstract

We study the possibility that the long term red timing-noise in pulsars originates from the evolution of the magnetic inclination angle $\chi$. The braking torque under consideration is a combination of the dipole radiation and the current loss. We find that the evolution of $\chi$ can give rise to extra cubic and fourth-order polynomial terms in the timing residuals. These two terms are determined by the efficiency of the dipole radiation, the relative electric-current density in the pulsar tube and $\chi$. The following observation facts can be explained with this model: a) young pulsars have positive $\ddot{\nu }$; b) old pulsars can have both positive and negative $\ddot{\nu }$; c) the absolute values of $\ddot{\nu }$ are proportional to $-\dot{\nu }$; d) the absolute values of the braking indices are proportional to the characteristic ages of pulsars. If the evolution of $\chi$ is purely due to rotation kinematics, then it can not explain the pulsars with braking index less than 3, and thus the intrinsic change of the magnetic field is needed in this case. Comparing the model with observations, we conclude that the drift direction of $\chi$ might oscillate many times during the lifetime of a pulsar. The evolution of $\chi$ is not sufficient to explain the rotation behavior of the Crab pulsar, because the observed $\chi$ and $\dot{\chi }$ are inconsistent with the values indicated from the timing residuals using this model.

5 pages, 1 figure. Accepted for publication in MNRAS

References in corpus (12)

• The ATNF Pulsar Catalogue
• Switched magnetospheric regulation of pulsar spin-down
• A periodically active pulsar giving insight into magnetospheric physics
• 45 Years of Rotation of the Crab Pulsar
• High-Altitude Emission from Pulsar Slot Gaps: The Crab Pulsar
• Evolution of the Magnetic Field Structure of the Crab Pulsar
• Rotational evolution of the Crab pulsar in the wind braking model
• Constraints on viewing geometries from radio observations of $\gamma$-ray-loud pulsars using a novel method
• Radio-to-TeV Phase-resolved Emission from the Crab Pulsar: The Annular Gap Model
• Why the braking indices of young pulsars are less than 3?
• On the role of the current loss in radio pulsar evolution
• Radio pulsars as progenitors of AXPs and SGRs: magnetic field evolution through pulsar glitches

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• Fluctuating neutron star magnetosphere: braking indices of eight pulsars, frequency second derivatives of 222 pulsars and 15 magnetars
• Pulse profiles and timing of PSR J1757$-$2421
• New pulse profile variability associated with a glitch of PSR J0738-4042
• Gravitational waves from pulsars with measured braking index
• The influence of quantum vacuum friction on pulsars
• Braking index jumps in young pulsars
• Phase Evolution of the Crab Pulsar between Radio and X-ray
• Application of a two dipole model to PSR J1640-4631, a pulsar with an anomalous braking index