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Related papers: Instabilities nulls and sub-pulse drift in radio p…

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We present the first observation of an instability in an expanding ultracold plasma. We observe periodic emission of electrons from an ultracold plasma in weak, crossed magnetic and electric fields, and a strongly perturbed electron density…

Plasma Physics · Physics 2008-11-06 X. L. Zhang , R. S. Fletcher , S. L. Rolston

Magnetospheres of pulsars are thought to be filled with plasma, and variations in plasma supply can affect both pulsar emission properties and spin-down rates. A number of recently discovered "intermittent" pulsars switch between two…

High Energy Astrophysical Phenomena · Physics 2015-06-03 Jason Li , Anatoly Spitkovsky , Alexander Tchekhovskoy

(abridged) The physics of the pulsar magnetosphere remains poorly constrained by observations. Little is known about their emission mechanism. Large vacuum gaps probably exist, and a non-neutral plasma partially fills the neutron star…

Astrophysics · Physics 2009-11-13 Jerome Petri

Recent operation of LOFAR by Hassall et al has produced severe constraints on the size and altitude of the 40 MHZ emission region in this pulsar. It is shown that these limits, given a limited number of unexceptionable assumptions,…

High Energy Astrophysical Phenomena · Physics 2015-06-16 P B Jones

The analytical expression for frequency of the maximum of radio emission intensity in pulsars with free electron emission from the stellar surface has been found. We have explained the correlation, known from observations, between the…

Solar and Stellar Astrophysics · Physics 2015-06-11 V. M. Kontorovich , A. B. Flanchik

We investigate self-consistent particle acceleration near a pulsar polar cap (PC) by the electrostatic field due to the effect of inertial frame dragging. Test particles gain energy from the electric field parallel to the open magnetic…

Astrophysics · Physics 2009-10-30 Alice K. Harding , Alexander G. Muslimov

Recent multi-frequency measurements of pulse widths W50 for the long-period pulsar J0250+5854 by Agar et al provide a unique insight to the emission process owing to its small polar-cap radius. The frequency-dependence of W50 can be simply…

High Energy Astrophysical Phenomena · Physics 2021-12-15 P B Jones

A number of previous papers have developed an ion-proton theory of the pulsar polar cap. The basic equations summarizing this are given here with the results of sets of model step-to-step calculations of pulse-precursor profiles. The nature…

High Energy Astrophysical Phenomena · Physics 2020-01-08 P B Jones

We study with a two-dimensional particle-in-cell simulation the stability of a discontinuity or piston, which separates an electron-positron cloud from a cooler electron-proton plasma. Such a piston might be present in the relativistic jets…

High Energy Astrophysical Phenomena · Physics 2020-10-13 M E Dieckmann , M Falk , D Folini , R Walder , P Stenedeg , I Hotz , A Ynnerman

The pair of drifting subpulses of the radio pulsar PSR B0031-07 appear to be well separated from each other on the average, overlapping at less than one thirtieth of the peak energy. Strictly, the integrated profile of the pair (after…

Astrophysics · Physics 2009-10-31 M. Vivekanand , B. C. Joshi

I summarize the status of pulsar theory, now 35 years after their discovery. Although progress has been made in understanding the relevant processes involved, there are several widely held misconceptions that are inhibiting further…

Astrophysics · Physics 2009-11-10 F. Curtis Michel

We study with a 3D PIC simulation discontinuities between an electron-positron pair plasma and magnetized electrons and protons. A pair plasma is injected at one simulation boundary with a speed 0.6$c$ along its normal. It expands into an…

Plasma Physics · Physics 2023-07-12 M E Dieckmann , D Folini , M Falk , A Bock , P Steneteg , R Walder

We consider the problem of the thermal X-ray radiation from the hot polar cap of radio pulsars showing evidence of \EB subpulse drift in radio band. In our recent Paper I, using the partially screened gap (PSG) model of inner acceleration…

Astrophysics · Physics 2008-11-26 J. Gil , G. I. Melikidze , B. Zhang

Observations suggest that in normal period radio pulsars, coherent curvature radiation is excited within 10$\%$ of the light cylinder. The coherence is attributed to Langmuir mode instability in a relativistically streaming one-dimensional…

High Energy Astrophysical Phenomena · Physics 2022-08-15 Sk. Minhajur Rahaman , Dipanjan Mitra , George I. Melikidze

Despite the fact that pulsars have been observed for almost half a century, many questions have remained unanswered. We use the analysis of X-ray observations in order to study the polar cap region of radio pulsars. The size of the hot…

High Energy Astrophysical Phenomena · Physics 2013-04-19 Andrzej Szary

The subpulse modulation of pulsar radio emission goes to prove that the plasma flow in the open field line tube breaks into isolated narrow streams. I propose a model which attributes formation of streams to the process of the electric…

High Energy Astrophysical Phenomena · Physics 2015-06-05 Yuri Lyubarsky

A novel scheme has been developed to show that the observed phase behaviour associated with subpulse drifting from two pulsars, J1034$-$3224 and J1720$-$2933, can be used to obtain the magnetic field configuration in the partially screened…

High Energy Astrophysical Phenomena · Physics 2023-05-24 Rahul Basu , Dipanjan Mitra , George I. Melikidze

Electrostatic oscillations in cold electron-positron plasmas can be coupled to a propagating electromagnetic mode if the background magnetic field is inhomogeneous. Previous work considered this coupling in the quasi-linear regime,…

Astrophysics · Physics 2007-05-23 C. R. Stark , D. A. Diver , A. A. da Costa

Periodic modulations are seen in normal period pulsars ($P >$ 0.1 sec) over timescales ranging from a few seconds to several minutes. Such modulations have usually been associated with the phenomenon of subpulse drifting. A number of recent…

High Energy Astrophysical Phenomena · Physics 2020-02-12 Rahul Basu , Dipanjan Mitra , Giorgi I. Melikidze

Expanding on the comment by Lyne et al (2017), that intermittent pulsars tend to congregate near a stripe in the logarithmic period versus period-derivative diagram, representing a small range of polar cap electric potential, as well as the…

High Energy Astrophysical Phenomena · Physics 2021-11-24 Fan Zhang