Understanding the spin-down rate changes of PSR B0919+06

Abstract

We study the spin-down properties of PSR B0919+06 based on almost 30 years of radio observations. We confirm that the time derivative of the rotational frequency $\dot{\nu }$ is modulated quasi-periodically and show that it exhibits a repeating double-peaked structure throughout the entire observation span. We model the $\dot{\nu }$ variation of the pulsar assuming two spin-down rates with sudden switches between them in time. Our results show that the double-peak structure in $\dot{\nu }$ has a repetition time of about 630 days until MJD 52000 (April 2001) and 550 days since then. During this cycle, the pulsar spin varies from the lower spin-down rate to the upper spin-down rate twice with different amounts of time spent in each state, resulting in a further quasi-stable secondary modulation of the two-state switching. This particular spin-down state switching is broadly consistent with free precession of the pulsar, however, a strong evidence linked with this mechanism is not clearly established. We also confirm that the pulsar occasionally emits groups of pulses which appear early in pulse phase, so-called "flares", and these events significantly contribute to the pulse profile shape. We find the $\dot{\nu }$ modulation and the pulse shape variations are correlated throughout the observations. However, the flare-state is not entirely responsible for this correlation. In addition to the flare-state, we detect flare-like events from the pulsar in single pulse observations. During these events, the shift in pulse phase is small compared to that of the main flare-state and clearly visible only in single pulse observations.

arXiv comment10 pages, 12 Figures, Accepted by MNRAS on 10 October 2014

References in corpus (21)

• Switched magnetospheric regulation of pulsar spin-down
• A periodically active pulsar giving insight into magnetospheric physics
• A study of 315 glitches in the rotation of 102 pulsars
• An analysis of the timing irregularities for 366 pulsars
• Pulsar Nulling and Mode Changing
• Pulsar Polar Cap Heating and Surface Thermal X-Ray Emission II. Inverse Compton Radiation Pair Fronts
• Resistive Solutions for Pulsar Magnetospheres
• Detection of 107 glitches in 36 southern pulsars
• The glitch-induced identity changes of PSR J1119-6127
• Toward a Realistic Pulsar Magnetosphere
• PSR J1841-0500: a radio pulsar that mostly is not there
• Precession of the Isolated Neutron Star PSR B1828-11
• Radio and X-ray observations of the intermittent pulsar J1832+0029
• A connection between radio state changing and glitch activity in PSR J0742-2822
• On the Spin-Down of Intermittent Pulsars
• Gamma-Ray Light Curves from Pulsar Magnetospheres with Finite Conductivity
• Pulsar state switching, timing noise and free precession
• Bistable Profile Illumination in Pulsars B0919+06 & B1859+07
• Long-term Radio Observations of the Intermittent Pulsar B1931+24
• Evidence for chaotic behaviour in pulsar spin-down rates
• Cyclical Changes in the Timing Residuals from the Pulsar B0919+06

Cited by in corpus (23)

• Comparing models of the periodic variations in spin-down and beam-width for PSR B1828-11
• Mode switching and oscillations in PSR B1828-11
• An in-depth investigation of 11 pulsars discovered by FAST
• Rapid Modification of Neutron Star Surface Magnetic Field: A proposed mechanism for explaining Radio Emission State Changes in Pulsars
• Quasi-Periodicities in the Anomalous Emission Events in Pulsars B1859+07 and B0919+06
• Pulsar bi-drifting: implications for polar cap geometry
• Radio Pulsars
• The LOFAR Tied-Array All-Sky Survey: Timing of 21 pulsars including the first binary pulsar discovered with LOFAR
• Scattering study of Pulsars below 100 MHz using LWA1
• Jiamusi Pulsar Observations: I. Abnormal emission events of PSR B0919+06
• Correlated spin-down rates and radio emission in PSR B1859+07
• Implications of the Occurrence of Glitches in Pulsar Free Precession Candidates
• Long term radio and X-ray evolution of the magnetar Swift J1818.0-1607
• Discovery of state transition behaviors in PSR J1124--5916
• On the free-precession candidate PSR B1828-11: Evidence for increasing deformation
• Multi-frequency study of the peculiar pulsars PSR B0919+06 and PSR B1859+07
• Multifrequency behaviour of the anomalous events of PSR J0922+0638
• On the variable timing behavior of PSR B0540-69: an almost excellent example to study pulsar braking mechanism
• Timing and emission variation of PSR J1733-3716
• Advances in our understanding of the free precession candidate PSR B1828-11
• Correlated emission and spin-down variability in radio pulsars
• Timing results of 22 years for PSR J0922+0638
• Long-term rotational and emission variability of 17 radio pulsars