What can the braking indices tell us about the nature of pulsars

  title={What can the braking indices tell us about the nature of pulsars},
  author={Youling Yue and Ren-xin Xu and W. W. Zhu},
  journal={Advances in Space Research},
Abstract As a result of observational difficulties, braking indices of only six rotation-powered pulsars are obtained with some certainty. All these values are remarkably smaller than the value ( n  = 3) expected for pure magnetodipole radiation model. Various models have been proposed to explain this phenomenon such as introducing additional torques by particle outflow or accretion disk, changes in inclination angle or magnetic field strength, and field-reconnection process in pulsar… Expand
Pulsar braking: magnetodipole vs. wind
Pulsars are good clocks in the universe. One fundamental question is that why they are good clocks? This is related to the braking mechanism of pulsars. Nowadays pulsar timing is done withExpand
Here we report that the observed braking indices of the 366 pulsars in the sample of Hobbs et al. range from about -10(8) to about +10(8) and are significantly correlated with their characteristicExpand
Observational Constraints on the Pulsar Wind Model: The Cases of Crab and Vela
As is well known, pulsars are extremely stable rotators. However, although slowly, they spindown thanks to brake mechanisms, which are in fact still a subject of intense investigation in theExpand
The influence of nondipolar magnetic field and neutron star precession on braking indices of radiopulsars
Some radiopulsars have anomalous braking index values n = ΩΩ/Ω 2 ~ ±(10 3 -10 4 ). It is shown that such anomalous values may be related to nondipolar magnetic field. Precession of a neutron starExpand
Rotational evolution of the Crab pulsar in the wind braking model
The pulsar wind model is updated by considering the effect of particle density and pulsar death. It can describe both the short-term and long-term rotational evolution of pulsars consistently. It isExpand
Spindown of magnetars: Quantum Vacuum Friction?
Magnetars are proposed to be peculiar neutron stars which could power their X-ray radiation by super-strong magnetic fields as high as ≳ 10 14 G. However, no direct evidence for such strong fieldsExpand
Measurements of radio pulsar braking indices
A quantitative analysis of radio pulsar timing noise is presented. Our analysis employs the recently reported strong correlation (with correlation coefficient r = 0.95) between the observed secondExpand
State-switching Mechanism of Intermittent Pulsars
The emission feature of intermittent pulsars is significant for understanding the pulsar emission mechanism. Using the observational evidence of radio emissions turning on and off and theExpand
Testing Models of Magnetic Field Evolution of Neutron Stars with the Statistical Properties of their Spin Evolutions
We test models for the evolution of neutron star (NS) magnetic fields (B). Our model for the evolution of the NS spin is taken from an analysis of pulsar timing noise presented by Hobbs et al.. WeExpand
On the variable timing behavior of PSR B0540-69: an almost excellent example to study pulsar braking mechanism
PSR B0540-69 has braking index measurement in its persistent state: n=2.129 \pm 0.012. Recently, it is reported to have spin-down state changes: a suddenly 36 % increase in the spin-down rate.Expand


Why the braking indices of young pulsars are less than 3
In this letter we discuss two possible reasons which cause the observed braking indices n of young radio pulsars to be smaller than 3: (a) the evolving spin-down model of the magnetic field componentExpand
Implications of a Constant Observed Braking Index for Young Pulsars' Spin-down
The observed braking index nobs, which has been determined for a few young pulsars, has been found to differ from the expected value for a rotating magnetic dipole model. In addition, the observedExpand
Pulsar braking index: a test of emission models?
Pulsar braking torques due to magnetodipole radiation and the unipolar generator are considered, which results in a braking index n of less than 3 and could be employed to test the emission models.Expand
The braking indices in pulsar emission models
Using the method proposed in a previous paper, we calculate pulsar braking indices in the models with torque contributions from both inner and outer accelerating regions, assuming that theExpand
New phase-coherent measurements of pulsar braking indices
Abstract Pulsar braking indices offer insight into the physics that underlies pulsar spin-down. Only five braking indices have been measured via phase-coherent timing; all measured values are lessExpand
Very low braking index for the Vela pulsar
THE rotation rate of a pulsar is thought to decrease with time according to a simple power law, with a 'braking index' equal to 3 if rotational energy is lost through radiation from a dipolarExpand
Disk-assisted Spin-down of Young Radio Pulsars
We present a model for the spin-down of young radio pulsars in which the neutron star loses rotational energy not only by emitting magnetic dipole radiation but also by torquing a surrounding diskExpand
A Braking Index for the Young, High Magnetic Field, Rotation-Powered Pulsar in Kesteven 75
We present the first phase-coherent measurement of a braking index for the young, energetic rotation-powered pulsar PSR J1846-0258. This 324 ms pulsar is located at the center of the supernovaExpand
The Crab pulsar has suffered in 1975 and 1989 two glitches in which the frequency did not relaxed to the extrapolated pre-glitch value but rather spun up showing long-term changes in the frequencyExpand
The role of reconnection in the pulsar magnetosphere
The present work is our first attempt to understand the role of reconnection in the pulsar magnetosphere. Our discussion is based on the observational inference that, as the pulsar spins down, theExpand