Theory of the radio emission of pulsars

Бескин, В. С.; Gurevich, A. V.; Istomin, Ya. N.

doi:10.1007/bf00637577

Cited by 79 publications

(106 citation statements)

References 70 publications

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“…The nature of birefringence is such that the two polarisations are spatially closer together at higher frequencies, and depolarisation will occur where they overlap. Beskin et al (1988) predicted that the two modes of propagation would result in two different indices: δ = −0.14 and δ = −0.29 for the ordinary mode and δ = −0.5 for the extraordinary mode. While our observations are compatible with either scenario or a combination of them, polarisation studies will help discern between the two interpretations of this phenomenon (see Noutsos et al 2015).…”

Section: Radius-to-frequency Mappingmentioning

confidence: 99%

Wide-band, low-frequency pulse profiles of 100 radio pulsars with LOFAR

Pilia

Hessels

Stappers

et al. 2016

A&A

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Context. LOFAR offers the unique capability of observing pulsars across the 10−240 MHz frequency range with a fractional bandwidth of roughly 50%. This spectral range is well suited for studying the frequency evolution of pulse profile morphology caused by both intrinsic and extrinsic effects such as changing emission altitude in the pulsar magnetosphere or scatter broadening by the interstellar medium, respectively. Aims. The magnitude of most of these effects increases rapidly towards low frequencies. LOFAR can thus address a number of open questions about the nature of radio pulsar emission and its propagation through the interstellar medium. Methods. We present the average pulse profiles of 100 pulsars observed in the two LOFAR frequency bands: high band (120-167 MHz, 100 profiles) and low band (15-62 MHz, 26 profiles). We compare them with Westerbork Synthesis Radio Telescope (WSRT) and Lovell Telescope observations at higher frequencies (350 and 1400 MHz) to study the profile evolution. The profiles were aligned in absolute phase by folding with a new set of timing solutions from the Lovell Telescope, which we present along with precise dispersion measures obtained with LOFAR. Results. We find that the profile evolution with decreasing radio frequency does not follow a specific trend; depending on the geometry of the pulsar, new components can enter into or be hidden from view. Nonetheless, in general our observations confirm the widening of pulsar profiles at low frequencies, as expected from radius-to-frequency mapping or birefringence theories.

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Section: Radius-to-frequency Mappingmentioning

confidence: 99%

Wide-band, low-frequency pulse profiles of 100 radio pulsars with LOFAR

Pilia

Hessels

Stappers

et al. 2016

A&A

View full text Add to dashboard Cite

show abstract

“…Over the years, many authors have argued for or against observational evidence that the magnetic axis aligns with the rotation axis: Proszynski (1979), Candy & Blair (1983, 1986, Lyne & Manchester (1988), McKinnon (1993), Gould (1994) and Gil & Han (1996). Beskin et al (1988) even argue in favour of counteralignment based on their magnetospheric theory. Recently Pandey & Prasad (1996) and Tauris & Manchester (1998) argue in favour of alignment.…”

Section: Evolution With B-field Decay and Alignmentmentioning

confidence: 99%

Torque decay in the pulsar $(P,\dot{P})$ diagram

Tauris¹,

Konar²

2001

A&A

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Abstract.We investigate the evolution of pulsars in the (P,Ṗ ) diagram. We first present analytical formulae to follow the evolution of a pulsar using simple exponential models for magnetic field decay and alignment. We then compare these evolutionary tracks with detailed model calculations using ohmic decay of crustal neutron star magnetic fields. We find that, after an initial phase with a small braking index, n, pulsars evolve with enhanced torque decay (n 3) for about 1 Myr. The long term evolution depends on the impurity parameter of the crust. If impurities are negligible in older isolated pulsars we expect their true age to be approximately equal to their observed characteristic age, τ = P/(2Ṗ ). It is not possible from data to constrain model parameters of the neutron star crust.

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“…We address the Ðrst shortcoming by expanding the electromagnetic Ðeld in cylindrical waves centered on r \ 0 and the second explicitly by considering general plasma modes. In a separate approach developed by Beskin, Gurevich, & Istomin (1986) an attempt was made to incorporate the collective e †ects of a plasma in an inhomogeneous magnetic Ðeld. The fundamentals of that approach have been seriously criticized (Nambu 1989 ;Machabeli 1995).…”

Section: Introductionmentioning

confidence: 99%

Cherenkov‐Curvature Radiation and Pulsar Radio Emission Generation

Lyutikov

Machabeli

Blandford

1999

ApJ

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Electromagnetic processes associated with a charged particle moving in a strong circular magnetic Ðeld are considered in cylindrical coordinates. We investigate the relation between the vacuum curvature emission and Cherenkov emission and argue that, for the superluminal motion of a particle in the inhomogeneous magnetic Ðeld in a dielectric, the combined e †ects of magnetic Ðeld inhomogeneity and the presence of a medium give rise to the synergetic Cherenkov-curvature emission process. We Ðnd the conditions under which the operator relations between electric Ðeld and electric displacement in cylindrical coordinates may be approximated by algebraic relations. For nonresonant electromagnetic waves, the interaction with particles streaming along the curved magnetic Ðeld may be described in the WKB approximation. For resonant waves interacting with superluminal particles we use a plane-wave approximation to compute the local dielectric tensor of a plasma in a weakly inhomogeneous magnetic Ðeld. We Ðnd in this approximation the polarization of normal modes in the plasma, Cherenkov-curvature and Cherenkov-drift emissivities and growth rates.

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Theory of the radio emission of pulsars

Cited by 79 publications

References 70 publications

Wide-band, low-frequency pulse profiles of 100 radio pulsars with LOFAR

Wide-band, low-frequency pulse profiles of 100 radio pulsars with LOFAR

Torque decay in the pulsar $(P,\dot{P})$ diagram

Cherenkov‐Curvature Radiation and Pulsar Radio Emission Generation

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