Fluctuating neutron star magnetosphere: braking indices of eight pulsars, frequency second derivatives of 222 pulsars and 15 magnetars

Abstract

Eight pulsars have low braking indices, which challenge the magnetic dipole braking of pulsars. 222 pulsars and 15 magnetars have abnormal distribution of frequency second derivatives, which also make contradiction with classical understanding. How neutron star magnetospheric activities affect these two phenomena are investigated by using the wind braking model of pulsars. It is based on the observational evidence that pulsar timing is correlated with emission and both aspects reflect the magnetospheric activities. Fluctuations are unavoidable for a physical neutron star magnetosphere. Young pulsars have meaningful braking indices, while old pulsars' and magnetars' fluctuation item dominates their frequency second derivatives. It can explain both the braking index and frequency second derivative of pulsars uniformly. The braking indices of eight pulsars are the combined effect of magnetic dipole radiation and particle wind. During the life time of a pulsar, its braking index will evolve from three to one. Pulsars with low braking index may put strong constraint on the particle acceleration process in the neutron star magnetosphere. The effect of pulsar death should be considered during the long term rotational evolution of pulsars. An equation like the Langevin equation for Brownian motion was derived for pulsar spin-down. The fluctuation in the neutron star magnetosphere can be either periodic or random, which result in anomalous frequency second derivative and they have similar results. The magnetospheric activities of magnetars are always stronger than those of normal pulsars.

12 pages, accepted for MNRAS

References in corpus (21)

• Switched magnetospheric regulation of pulsar spin-down
• A periodically active pulsar giving insight into magnetospheric physics
• 45 Years of Rotation of the Crab Pulsar
• Magnetars: Properties, Origin and Evolution
• Detection of 107 glitches in 36 southern pulsars
• The Prelude to and Aftermath of the Giant Flare of 2004 December 27: Persistent and Pulsed X-ray Properties of SGR 1806-20 from 1993 to 2005
• Population synthesis of isolated Neutron Stars with magneto--rotational evolution
• Radio emission evolution, polarimetry and multifrequency single pulse analysis of the radio magnetar PSR J1622-4950
• Radio and X-ray observations of the intermittent pulsar J1832+0029
• Magnetic field growth in young glitching pulsars with a braking index
• Rotational evolution of young pulsars due to superfluid decoupling
• Rotational evolution of the Crab pulsar in the wind braking model
• Radio-to-TeV Phase-resolved Emission from the Crab Pulsar: The Annular Gap Model
• Constraints on viewing geometries from radio observations of $\gamma$-ray-loud pulsars using a novel method
• Repeated, Delayed Torque Variations Following X-ray Flux Enhancements in the Magnetar 1E1048.1$-$5937
• Why the braking indices of young pulsars are less than 3?
• Gamma-ray Emission from the Vela Pulsar Modeled with the Annular Gap and Core Gap
• Discovery of a Spin-Down State Change in the LMC Pulsar B0540-69
• X-ray and radio observations of the magnetar Swift J1834.9-0846 and its dust-scattering halo
• The Vela Pulsar With an Active Fallback Disk
• Central compact objects, superslow X-ray pulsars, gamma-ray bursts: do they have anything to do with magnetars?

Cited by in corpus (14)

• A New, Low Braking Index For the LMC Pulsar B0540-69
• Inclination angle and braking index evolution of pulsars with plasma-filled magnetosphere: application to high braking index of PSR J1640-4631
• Physics and astrophysics of strong magnetic field systems with eXTP
• Possible evolution of the pulsar braking index from larger than three to about one
• Results of 12 Years of Pulsar Timing at Nanshan -- I
• Pulse profiles and timing of PSR J1757$-$2421
• The Nonstandard Properties of a "Standard" PWN: Unveiling the Mysteries of PWN G21.5-0.9 Using its IR and X-ray emission
• Rotational Evolution of The Slowest Radio Pulsar PSR J0250+5854
• Gravitational waves from pulsars with measured braking index
• The braking index of PSR B0540-69 and the associated pulsar wind nebula emission after spin-down rate transition
• Refinement of the timing-based estimator of pulsar magnetic fields
• Timing and Evolution of PSR B0950+08
• Spacetime geometry fluctuations and geodesic deviation
• Unifying neutron star sub-populations in the supernova fallback accretion model