Optical Timing of the Crab Pulsar, NP 0532

Boynton, P. E.; Groth, Edward J.; Hutchinson, D. P.; Nanos, G. P.; Partridge, R. B.; Wilkinson, D. T.

doi:10.1086/151550

Cited by 143 publications

(97 citation statements)

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“…Timing noise may result from a random walk in the pulse phase, spin or spin down, which would give power-law spectra for the timing residuals (S(f ) ∝ f α ) with spectral indices α = −2, −4 or −6 respectively (Boynton et al 1972). But there is some argument that it cannot simply be modelled as a random walk (e.g., Cordes & Downs 1985;Hobbs et al 2010).…”

Section: Introductionmentioning

confidence: 99%

Pulse profiles and timing of PSR J1757−2421

Yuan

Manchester

Wang

et al. 2016

Mon. Not. R. Astron. Soc.

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Pulse arrival time measurements over fourteen years with the Nanshan 25-m and Parkes 64-m radio telescopes have been used to determine the average profile and timing properties for PSR J1757−2421 (B1754−24). Analysis of the radio profile data shows a large variation of spectral index across the profile and an unusual increase in component separation with increasing frequency. The timing observations show that PSR B1754−24 underwent a large glitch with a fractional increase in spin frequency of ∆ν g /ν ∼ 7.8×10 −6 in May 2011. At the time of the glitch there was a large permanent jump in the rotational frequency accompanied by two exponential recovery terms with timescales of 15(6) and 97(15) days, respectively.

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Section: Introductionmentioning

confidence: 99%

Pulse profiles and timing of PSR J1757−2421

Yuan

Manchester

Wang

et al. 2016

Mon. Not. R. Astron. Soc.

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“…Most importantly, the observed quasi-sinusoidal variations in both the DM and the time offset between the low-and high-frequency timing data are difficult to explain in the context of the planetary scenario. Alternative explanation of the present observation in terms of timing noise − either in the form of random walks (Boynton et al 1972) or some large-scale internal oscillations of neutron star (Ruderman 1970) − has difficulties in accounting for both the sustained regular cyclic pattern and the observed periodicities in the data. Furthermore, it is highly improbable that timing noise of any sort could plausibly explain the observed variations in both the DM and the dual-frequency residual offsets.…”

Section: Discussionmentioning

confidence: 84%

Periodicities in rotation and DM of PSR B1557–50

Chukwude¹,

Ubachukwu²,

Okeke³

2003

A&A

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Abstract.We have analysed the pulse arrival time data of the pulsar B1557−50 collected over a period of nearly 13 years, from 1986 July to 1999 May, in order to investigate the long-term spin behaviour. The results reveal sustained cyclic variations in both the timing residuals and dispersion measure (DM) of this object. Both the timing and DM sequences are well described by two harmonically-related periodicities of ∼1600 and 800 days. The variations in spin-down rate and DM are significantly anticorrelated in the sense that maximumν corresponds to minimum DM. Interpretation of the data in terms of free precession of an isolated radio pulsar suggests a wobble angle θ ≈ 0.01• . The data are consistent with at least 6.5% of the stellar moment of inertia being coupled to the crust.

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“…Furthermore, the rate and amplitude of resolved events can be readily understood in terms of a random process, both from the point of view of a series of random jumps comprising such a process, or as the large-amplitude end of a broad distribution of microglitches in one or more of the rotation variables that comprise the noise process. The random walks in (/), v and I. considered by Boynton et al (1972) and other workers can be explained by random changes in the emission region or beam direction, moment of inertia of the star, and the process of rotational energy loss respectively.…”

Section: The Characterisation Of Timing Noisementioning

confidence: 93%

“…Timing noise was first recognised by Boynton et al (1972), who examined the first two years of timing data from the Crab pulsar. After modelling the pulsar slow-down and a glitch, they found that a quasi-sinusoidal structure remained in the residuals over time spans of a month or more.…”

Section: The Characterisation Of Timing Noisementioning

confidence: 99%

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Timing observations of southern pulsars - 1987 to 1991

D’Alessandro

McCulloch

King

et al. 1993

Monthly Notices of the Royal Astronomical Society

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Pulse arrival-time measurements made at frequencies near 670 and 800 MHz over a 7-year period have been used to study the timing behaviour of 45 southern pulsars. These measurements have resulted in more accurate estimates of the period, period derivative, position and dispersion measure of most of these pulsars. Changes in some of the dispersion measures have been detected and used to estimate the scale-sizes and electron densities of irregularities in the interstellar medium. The timing measurements also revealed distinct jumps in the rotation rate of five pulsars, most of which have not been reported elsewhere.Polarimetric data at 670 and 800 MHz are presented for eighteen of the more luminous pulsars. The integrated profiles display properties in general agreement with trends extrapolated from other frequencies. Rotation measures have been derived for these pulsars. Nine are more accurate than previous determinations, and two have changed since they were last measured. These changes suggest a dense, magnetised electron cloud has moved into or out of the line of sight.It has been confirmed that the level of pulsar timing noise is correlated with spin-down rates. Further analyses have revealed that, in most pulsars, the observed timing noise is due to a mixture of different kinds of activity, such as random walk processes, microjumps, and for one pulsar, free precession of the spin axis. The microjumps are characterised by a variety of signatures, involving both positive and negative changes in the rotation frequency and frequency derivative. The amplitudes of these microjumps form the tail-end of a continuous distribution of amplitudes extending down to microglitch level. An investigation of timing noise in the Vela pulsar has shown that the microactivity during the postglitch recovery period is dominated by microjumps in the rotation frequency and frequency derivative which occur every 30-40 days. This microactivity is also punctuated by less frequent events, such as large steps in the frequency derivative, discrete changes in the frequency second derivative, and in one isolated case, a small glitch. The above results have been discussed in terms of current theories of pulsar timing noise and it was found that no theoretical model, in isolation, is able to explain the range of observed timing activity in the pulsars studied.Power spectra of the pulsar timing residuals have been derived using a novel technique based on the CLEAN algorithm. Most of the spectra are well described by a single-or double-component power-law model. Some of these spectra can be interpreted in the context of one or more of the current timing noise models.

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Optical Timing of the Crab Pulsar, NP 0532

Cited by 143 publications

References 0 publications

Pulse profiles and timing of PSR J1757−2421

Pulse profiles and timing of PSR J1757−2421

Periodicities in rotation and DM of PSR B1557–50

Timing observations of southern pulsars - 1987 to 1991

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