English
Related papers

Related papers: High-Energy Radiation from Pulsars : A Three Dimen…

200 papers

My thesis deals with a fundamental question of high energy gamma-ray astronomy. Namely, I studied the cut-off shape of the Crab pulsar spectrum to distinguish between the leading scenarios for the pulsar models. Pulsars are celestial…

High Energy Astrophysical Phenomena · Physics 2011-05-18 Takayuki Saito

The $Fermi$-LAT has revealed that rotation powered millisecond pulsars (MSPs) are a major contributor to the Galactic $\gamma$-ray source population. Such pulsars may also be important in modeling the quiescent state of several low mass…

High Energy Astrophysical Phenomena · Physics 2015-06-03 J. Takata , K. S. Cheng , R. E. Taam

We re-examine the outer gap size by taking the geometry of the dipole magnetic field into account. Furthermore, we also consider that instead of taking the gap size at half of the light cylinder radius to represent the entire outer gap it…

Astrophysics · Physics 2009-11-10 L. Zhang , K. S. Cheng , Z. J. Jiang , P. Leung

We investigate the shapes of \gamma-ray pulsar light curves using 3D pulsar magnetosphere models of finite conductivity. These models, covering the entire spectrum of solutions between vacuum and force-free magnetospheres, for the first…

High Energy Astrophysical Phenomena · Physics 2015-06-05 Constantinos Kalapotharakos , Alice K. Harding , Demosthenes Kazanas , Ioannis Contopoulos

We use the outer gap model to explain the spectrum and the energy dependent light curves of the X-ray and soft gamma-ray radiations of the spin-down powered pulsar PSR B1509-58. In the outer gap model, most pairs inside the gap are created…

High Energy Astrophysical Phenomena · Physics 2015-06-12 Y. Wang , J. Takata , K. S. Cheng

We investigate the particle accelerator that arises in a rotating neutron-star magnetosphere. Solving the Poisson equation for the electro-static potential, the Boltzmann equations for relativistic electrons and positrons, and the radiative…

High Energy Astrophysical Phenomena · Physics 2015-06-23 Kouichi Hirotani

We calculate the spectrum of blast wave models of gamma-ray burst sources, for various assumptions about the magnetic field density and the relativistic particle acceleration efficiency. For a range of physically plausible models we find…

Astrophysics · Physics 2011-09-30 P. Meszaros , M. J. Rees , H. Papathanassiou

A synthesis of the present knowledge on gamma-ray emission from the magnetosphere of a rapidly rotating neutron star is presented, focusing on the electrodynamics of particle accelerators. The combined curvature, synchrotron, and…

Astrophysics · Physics 2009-11-11 Kouichi Hirotani

We previously obtained constraints on the viewing geometries of 6 Fermi LAT pulsars using a multiwavelength approach (Seyffert et al., 2011). To obtain these constraints we compared the observed radio and $\gamma$-ray light curves (LCs) for…

High Energy Astrophysical Phenomena · Physics 2015-01-28 A. S. Seyffert , C. Venter , T. J. Johnson , A. K. Harding

Forty years after the discovery of rotation-powered pulsars, we still do not understand many aspects of their pulsed emission. In the last few years there have been some fundamental developments in acceleration and emission models. I will…

Astrophysics · Physics 2007-10-19 Alice K. Harding

(abridged) Thanks to the recent discovery by Fermi of about fifty new gamma-ray pulsars, it becomes possible to look for statistical properties of their pulsed high-energy emission, especially their light-curves and phase-resolved spectra.…

High Energy Astrophysical Phenomena · Physics 2015-05-20 Jérôme Pétri

The Fermi Gamma-Ray Space Telescope has discovered many gamma-ray pulsars, both as radio-loud objects and radio-quiet or radio-weak pulsars that have been identified through blind period searches. The latter presumably have gamma-ray beams…

High Energy Astrophysical Phenomena · Physics 2010-02-02 Marco Pierbattista , Isabelle Grenier , Alice Harding , Peter Gonthier

We review the recent advances in the pulsar high-energy $\gamma$-ray observation and the electrodynamics of the pulsar magnetospheres from the early vacuum model to the recent plasma-filled models by the numerical simulations. The numerical…

High Energy Astrophysical Phenomena · Physics 2024-03-12 Gang Cao , Xiongbang Yang , Li Zhang

Using all available multi-component radio pulse profiles for pulsars with medium to long periods and good polarisation data, we have constructed a two-dimensional image of the mean radio beamshape. This shows a peak near the centre of the…

Astrophysics · Physics 2009-10-31 J. L. Han , R. N. Manchester

We investigate the $\gamma$-ray emission from a outer-gap accelerator, which is located in the outer-magnetosphere of a pulsar. The charge depletion from the Goldreich-Julian density causes a large electric field along the magnetic field…

Astrophysics · Physics 2009-11-10 J. Takata , S. Shibata , K. Hirtotani

We investigate particle accelerators in rotating neutron-star magnetospheres, by simultaneously solving the Poisson equation for the electrostatic potential together with the Boltzmann equations for electrons, positrons and photons on the…

Astrophysics · Physics 2007-05-23 Kouichi Hirotani

Thermal emission from the surface of an ultramagnetic neutron star is believed to contribute significantly to the soft X-ray flux of the Anomalous X-ray Pulsars. We compare the detailed predictions of models of the surface emission from a…

Astrophysics · Physics 2009-11-06 Feryal Ozel , Dimitrios Psaltis , Victoria M. Kaspi

The multi-wavelength pulsed emission from young pulsars and millisecond pulsars can be well modeled with the single-pole 3-dimension annular gap and core gap model. To distinguish our single magnetic pole model from two-pole models (e.g.…

High Energy Astrophysical Phenomena · Physics 2015-06-11 YuanJie Du , GuoJun Qiao

We explore the multiwavelength radiation properties of the light curves and energy spectra in the dissipative magnetospheres of pulsars. The dissipative magnetospheres are simulated by the pseudo-spectral method with the combined force-free…

High Energy Astrophysical Phenomena · Physics 2024-03-12 Xiongbang Yang , Gang Cao

The extended nebulae formed as pulsar winds expand into their surroundings provide information about the composition of the winds, the injection history from the host pulsar, and the material into which the nebulae are expanding.…

Astrophysics · Physics 2009-11-13 Patrick Slane