English
Related papers

Related papers: Polar-cap accelerator and radio emission from puls…

200 papers

We study electron-positron pair production in polar caps of energetic pulsars to determine the maximum multiplicity of pair plasma a pulsar can produce under the most favorable conditions. This paper complements and updates our study of…

High Energy Astrophysical Phenomena · Physics 2019-01-23 A. N. Timokhin , A. K. Harding

Radio-bright regions near the solar poles are frequently observed in Nobeyama Radioheliograph (NoRH) maps at 17 GHz, and often in association with coronal holes. However, the origin of these polar brightening has not been established yet.…

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

Circularly polarized colliding laser pulses can create abundant electron-positron pair plasma [A. R. Bell and J. G. Kirk, Phys. Rev. Lett. 101, 200403 (2008)], which scattering the incoming electromagnetic waves can prevent them from…

As a large-scale motion on the Sun, the meridional flow plays an important role in determining magnetic structure and strength and solar cycle. However, the meridional flow near the solar poles is still unclear. The Hinode observations show…

Solar and Stellar Astrophysics · Physics 2024-07-29 Shuhong Yang , Jie Jiang , Zifan Wang , Yijun Hou , Chunlan Jin , Qiao Song , Yukun Luo , Ting Li , Jun Zhang , Yuzong Zhang , Guiping Zhou , Yuanyong Deng , Jingxiu Wang

Axions can be copiously produced in localized regions of neutron star magnetospheres where the ambient plasma is unable to efficiently screen the induced electric field. As these axions stream away from the neutron star they can resonantly…

High Energy Physics - Phenomenology · Physics 2023-07-26 Dion Noordhuis , Anirudh Prabhu , Samuel J. Witte , Alexander Y. Chen , Fábio Cruz , Christoph Weniger

A numerical framework to calculate the height and potential of the vacuum inner gap of pulsars is presented here. % The results demonstrate that small mountains on a pulsar's polar cap tend to significantly influence the properties of the…

High Energy Astrophysical Phenomena · Physics 2025-12-12 Zi-Hao Xu , Wei-Yang Wang , Shun-Shun Cao , Ren-Xin Xu

We have derived the relationship between polarization and intensity fluctuations due to point sources. In the case of a Poisson distribution of a population with uniform evolution properties and constant polarization degree, polarization…

Astrophysics · Physics 2009-10-31 G. De Zotti , C. Gruppioni , P. Ciliegi , C. Burigana , L. Danese

The majority of X-ray-detected rotation-powered millisecond pulsars (MSPs) appear to exhibit predominantly thermal emission, believed to originate from the heated magnetic polar caps of the pulsar. In the nearest MSP, J0437--4715 a faint PL…

Astrophysics · Physics 2007-05-23 Slavko Bogdanov , Jonathan E. Grindlay , George B. Rybicki

The topology of the electromagnetic field around neutron stars severely impacts pulsar physics. While most of the works assume a standard centred dipolar magnetic field model, recently some efforts have been made to explain how inclusion of…

High Energy Astrophysical Phenomena · Physics 2017-07-27 Anu Kundu , Jerome Petri

Spectacular results of pulsar observations in X-ray and gamma-ray domains gave a new boost to theoretical models of pulsar magnetospheric activity. A challenging aspect of these efforts is that lightcurves and broadband energy spectra of…

Astrophysics · Physics 2007-05-23 B. Rudak , J. Dyks , T. Bulik

Sub-pulse drifting has been regarded as one of the most insightful aspects of the pulsar radio emission. The phenomenon is generally explained with a system of emission sub-beams rotating around the magnetic axis, originating from a…

High Energy Astrophysical Phenomena · Physics 2018-08-22 Yogesh Maan

Magnetars are the most strongly magnetized neutron stars, and one of the most promising targets for X-ray polarimetric measurements. We present here the first Imaging X-ray Polarimetry Explorer (IXPE) observation of the magnetar 1RXS…

High Energy Astrophysical Phenomena · Physics 2023-02-22 Silvia Zane , Roberto Taverna , Denis Gonzalez Caniulef , Fabio Muleri , Roberto Turolla , Jeremy Heyl , Keisuke Uchiyama , Mason Ng , Toru Tamagawa , Ilaria Caiazzo , Niccolo' Di Lalla , Herman L. Marshall , Matteo Bachetti , Fabio La Monaca , Ephraim Gau , Alessandro Di Marco , Luca Baldini , Michela Negro , Nicola Omodei , John Rankin , Giorgio Matt , George G. Pavlov , Takao Kitaguchi , Henric Krawczynski , Fabian Kislat , Ruth Kelly , Ivan Agudo , Lucio A. Antonelli , Wayne H. Baumgartner , Ronaldo Bellazzini , Stefano Bianchi , Stephen D. Bongiorno , Raffaella Bonino , Alessandro Brez , Niccolo' Bucciantini , Fiamma Capitanio , Simone Castellano , Elisabetta Cavazzuti , Chieng Ting Chen , Stefano Ciprini , Enrico Costa , Alessandra De Rosa , Ettore Del Monte , Laura Di Gesu , Immacolata Donnarumma , Victor Doroshenko , Michal Dovciak , Steven R. Ehlert , Teruaki Enoto , Yuri Evangelista , Sergio Fabiani , Riccardo Ferrazzoli , Javier A. Garcia , Shuichi Gunji , Kiyoshi Hayashida , Wataru Iwakiri , Svetlana G. Jorstad , Philip Kaaret , Vladimir Karas , Jeffery J. Kolodziejczak , Luca Latronico , Ioannis Liodakis , Simone Maldera , Alberto Manfreda , Frederic Marin , Andrea Marinucci , Alan P. Marscher , Francesco Massaro , Ikuyuki Mitsuishi , Tsunefumi Mizuno , C. Y. Ng , Stephen L. O'Dell , Chiara Oppedisano , Alessandro Papitto , Abel L. Peirson , Matteo Perri , Melissa Pesce Rollins , Pierre Olivier Petrucci , Maura Pilia , Andrea Possenti , Juri Poutanen , Simonetta Puccetti , Brian D. Ramsey , Ajay Ratheesh , Oliver J. Roberts , Roger W. Romani , Carmelo Sgro' , Patrick Slane , Paolo Soffitta , Gloria Spandre , Douglas A. Swartz , Fabrizio Tavecchio , Yuzuru Tawara , Allyn F. Tennant , Nicholas E. Thomas , Francesco Tombesi , Alessio Trois , Sergey S. Tsygankov , Jacco Vink , Martin C. Weisskopf , Kinwah Wu , Fei Xie

We present numerical simulations of electron-positron pair cascades in the magnetospheres of magnetic neutron stars for a wide range of surface fields (B_p = 10^{12}--10^{15} G), rotation periods (0.1--10 s), and field geometries. This has…

High Energy Astrophysical Phenomena · Physics 2012-07-31 Zach Medin , Dong Lai

Observations of the thermal X-ray emission from old radio pulsars implicate that the size of hot spots is much smaller then the size of the polar cap that follows from the purely dipolar geometry of pulsar magnetic field. Plausible…

High Energy Astrophysical Phenomena · Physics 2012-07-20 Andrzej Szary , George Melikidze , Janusz Gil

For many years it has been considered puzzling how pulsar radio emission, supposedly created by a circulating carousel of sub-beams, can produce the driftbands demonstrated by PSR J0815+09, and more recently PSR B1839-04, which…

High Energy Astrophysical Phenomena · Physics 2016-11-23 Geoff Wright , Patrick Weltevrede

For a subclass of polar-cap models based on electromagnetic cascades induced by curvature radiation (CR) we calculate broad-band high-energy spectra of pulsed emission expected for classical and millisecond pulsars. The spectra are a…

Astrophysics · Physics 2009-10-31 B. Rudak , J. Dyks

In an earlier paper, we introduced a model for pulsars in which non-radial oscillations of high spherical degree (\el) aligned to the magnetic axis of a spinning neutron star were able to reproduce subpulses like those observed in…

Astrophysics · Physics 2009-11-13 J. Christopher Clemens , R. Rosen

We derive easy-to-handle approximations for the polar gap electric field due to inertial frame dragging as derived by Harding & Muslimov 1998. A simple formula valid for polar gap height comparable to the polar cap radius is presented.

Astrophysics · Physics 2007-05-23 J. Dyks , B. Rudak

We investigate polarization of high-energy emissions from the Crab pulsar in the frame work of the outer gap accelerator, following previous works of Cheng and coworkers. The recent version of the outer gap, which extends from inside the…

Astrophysics · Physics 2016-08-31 J. Takata , H. -K. Chang , K. S. Cheng