Dual Spin-Down States of the Pulsar J1001-5507

Chukwude, A. E.; Buchner, S.

doi:10.1088/0004-637x/745/1/40

Cited by 6 publications

(8 citation statements)

References 37 publications

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“…Alternatively, our timing noise model may be incomplete, giving rise to the preference for the PLRN+F2 model. For instance, PSR J0738−4042 may be affected by torque variations initially induced after a profile change in 2005, proposed to be evidence for an interaction with an asteroid (Brook et al 2014), while PSR J1001−5507 is known to exhibit discrete spin-down state switching (Chukwude & Buchner 2012). Neither phenomenon is included in the timing models for these pulsars, and are therefore likely causes of these pulsars' strong preference for the PLRN+F2 model.…”

Section: Spin Frequency Second Derivatives and Braking Indicesmentioning

confidence: 99%

The UTMOST pulsar timing programme – II. Timing noise across the pulsar population

Lower

Bailes

Shannon

et al. 2020

Monthly Notices of the Royal Astronomical Society

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While pulsars possess exceptional rotational stability, large scale timing studies have revealed at least two distinct types of irregularities in their rotation: red timing noise and glitches. Using modern Bayesian techniques, we investigated the timing noise properties of 300 bright southern-sky radio pulsars that have been observed over 1.0-4.8 years by the upgraded Molonglo Observatory Synthesis Telescope (MOST). We reanalysed the spin and spin-down changes associated with nine previously reported pulsar glitches, report the discovery of three new glitches and four unusual glitch-like events in the rotational evolution of PSR J1825−0935. We develop a refined Bayesian framework for determining how red noise strength scales with pulsar spin frequency (ν) and spin-down frequency (ν), which we apply to a sample of 280 non-recycled pulsars. With this new method and a simple power-law scaling relation, we show that red noise strength scales across the non-recycled pulsar population as ν a |ν| b , where a = −0.84 +0.47 −0.49 and b = 0.97 +0.16 −0.19 . This method can be easily adapted to utilise more complex, astrophysically motivated red noise models. Lastly, we highlight our timing of the double neutron star PSR J0737−3039, and the rediscovery of a bright radio pulsar originally found during the first Molonglo pulsar surveys with an incorrectly catalogued position.

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Section: Spin Frequency Second Derivatives and Braking Indicesmentioning

confidence: 99%

The UTMOST pulsar timing programme – II. Timing noise across the pulsar population

Lower

Bailes

Shannon

et al. 2020

Monthly Notices of the Royal Astronomical Society

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“…A delayed spin-up of spin frequency in the Crab pulsar during the largest glitch itself is related with a rapid increase in | ν| (Shaw et al 2018;Ge et al 2020a). The transition between the dual spin-down states together with the steady increase in | ν| of PSR J1001-5507 is accompanied by pulse shape variations (Chukwude & Buchner 2012), establishing a firm correlation.…”

Section: Discussionmentioning

confidence: 79%

New pulse profile variability associated with the glitch of PSR J0738-4042

Zhou¹,

E.²,

Yuan³

et al. 2022

Preprint

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The close correlation observed between emission state and spin-down rate change of pulsars has many implications both for the magnetospheric physics and the neutron star interior. The middle-aged pulsar PSR J0738-4042, which had been observed to display variations in the pulse profile associated with its spin-down rate change due to external effects, is a remarkable member of this class. In this study, based on the 12.5-yr combined public timing data from UTMOST and Parkes, we have detected a new emission-rotation correlation in PSR J0738-4042 concurrent with a glitch. The first glitch occurred in this pulsar at MJD 57359(5) (December 3, 2015) is considered to be underlying reason of the variability. Unlike the usual glitch behaviours, the braking torque on the pulsar has continued to increase over 1380 d since small spin-up event (∆ν/ν ∼ 0.36(4) × 10 −9 ), corresponding to a significant decrease in ν. As for changes in the pulse profile after the glitch, the relative amplitude of the leading component weakens drastically, while the middle component becomes stronger. A combined model of crustquake induced platelet movement and vortex creep response is invoked to account for this rare correlation. In this scenario, magnetospheric statechange is naturally linked to the pulsar-intrinsic processes that give rise to a glitch.

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“…Models of TN include random walks, microglitches, long-term systematic excursions of pulsar spin properties and/or some mixtures of two or more of these activities (e.g. Boynton et al 1972;Cordes & Downs 1985;D'Alessandro et al 1995;Chukwude 2002;Lyne et al 2010;Chukwude & Buchner 2012). On the other hand, WN denotes all fluctuations that have white spectra: equal levels of power at all fluctuation frequencies (e.g.…”

Section: Theory Of Relationshipsmentioning

confidence: 99%

“…However, it is widely believed that TN activities arise from processes intrinsic to the rotating neutron stars. A popular proposition is that pulsar TN arises from some form of variations in the coupling between neutron star crust and its superfluid core (Jones 1990;D'Alessandro 1996) and/or torque fluctuations in the magnetosphere (Cheng 1987;Kramer et al 2006;Lyne et al 2010;Chukwude & Buchner 2012). Lately, analysis of improved timing data has revealed that the spin properties of a sizeable population of pulsars, on a wide range of timescales (> ∼ 10 years), are strongly dominated by random fluctuations whose statistics are characterized by ensemble average power that is independent of fluctuation frequencies (Cordes & Downs 1985).…”

Section: Introductionmentioning

confidence: 99%

Assessing the effects of timing irregularities on radio pulsars anomalous braking indices

Chukwude

Odo

2016

Res. Astron. Astrophys.

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We investigate the statistical effects of non-discrete timing irregularities on observed radio pulsar braking indices using correlations between the second derivative of the measured anomalous frequency (ν obs ) and some parameters that have been widely used to quantify pulsar timing fluctuations (the timing activity parameter (A), the amount of timing fluctuations absorbed by the cubic term (σ R23 ) and a measure of pulsar rotational stability (σ z )) in a large sample of 366 Jodrell Bank Observatory radio pulsars. The result demonstrates that anomalous braking indices are largely artifacts produced by aggregations of fluctuations that occur within or outside the pulsar system. For a subsample of 223 normal radio pulsars whose observed timing activity appeared consistent with instabilities in rotation of the underlying neutron stars (or timing noise) over timescales of ∼ 10 − 40 yr, |ν obs | strongly correlates (with correlation coefficient |r| ∼ 0.80 − 0.90) with the pulsar timing activity parameters and spin-down properties. On the other hand, no meaningful correlations (r < 0.3) were found between νobs and the timing activity diagnostics and spindown parameters in the remaining 143 objects, whose timing activity appears significantly dominated by white noise fluctuations. The current result can be better understood if the timing noise in isolated pulsars originates from intrinsic spin-down processes of the underlying neutron stars, but white noise fluctuations largely arise from processes external to the pulsar system.

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Dual Spin-Down States of the Pulsar J1001-5507

Cited by 6 publications

References 37 publications

The UTMOST pulsar timing programme – II. Timing noise across the pulsar population

The UTMOST pulsar timing programme – II. Timing noise across the pulsar population

New pulse profile variability associated with the glitch of PSR J0738-4042

Assessing the effects of timing irregularities on radio pulsars anomalous braking indices

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