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There is a growing new class of young spin-down powered pulsars called GeV-quiet soft gamma-ray pulsar; (1) spectral turnover appears around~10MeV, (2) the X-ray spectra of below 20 keV can be described by power law with photon index around…

High Energy Astrophysical Phenomena · Physics 2015-06-22 Y. Wang , C. W. Ng , J. Takata , Gene C. K. Leung , K. S. Cheng

The equatorial current sheet in pulsar magnetospheres is often regarded as an ideal site for particle acceleration via relativistic reconnection. Using 2D spherical particle-in-cell simulations, we investigate particle acceleration in the…

High Energy Astrophysical Phenomena · Physics 2015-06-23 Benoît Cerutti , Alexander Philippov , Kyle Parfrey , Anatoly Spitkovsky

The unexplained excess gamma-ray emission from the Milky Way's Galactic Center has puzzled astronomers for nearly a decade. Two theories strive to explain the origin of this excess: self-annihilating dark matter particles or an unresolved…

High Energy Astrophysical Phenomena · Physics 2022-05-10 Oliver Boodram , Craig O. Heinke

We analytically investigate the condition for a particle accelerator to be active in the outer magnetosphere of a rotation-powered pulsar. Within the accelerator (or the gap), magnetic-field-aligned electric field accelerates electrons and…

High Energy Astrophysical Phenomena · Physics 2015-05-28 Ren-Bo Wang , Kouichi Hirotani

(Abridged) Gamma-ray emission from pulsars has long been modeled using a vacuum dipole field. This approximation ignores changes in the field structure caused by the magnetospheric plasma and strong plasma currents. We present the first…

High Energy Astrophysical Phenomena · Physics 2014-11-20 Xue-Ning Bai , Anatoly Spitkovsky

We have simulated a population of young spin-powered pulsars and computed the beaming pattern and lightcurves for the three main geometrical models: polar cap emission, two-pole caustic ("slot gap") emission and outer magnetosphere…

Astrophysics · Physics 2011-02-11 Kyle P. Watters , Roger W. Romani , Patrick Weltevrede , Simon Johnston

The high-quality Fermi LAT observations of gamma-ray pulsars have opened a new window to understanding the generation mechanisms of high-energy emission from these systems. The high statistics allow for careful modeling of the light curve…

High Energy Astrophysical Phenomena · Physics 2011-11-03 Megan E. DeCesar , Alice K. Harding , M. Coleman Miller , Ioannis Contopoulos , Constantinos Kalapotharakos , Damien Parent

Some pulsars have their maximum observable energy output in the gamma-ray band, offering the possibility of using these high-energy photons as probes of the particle acceleration and interaction processes in pulsar magnetospheres. After an…

Astrophysics · Physics 2009-06-23 D. J. Thompson

We study the gamma-ray emissions from an outer-magnetospheric potential gap around a rotating neutron star. Migratory electrons and positrons are accelerated by the electric field in the gap to radiate copious gamma-rays via curvature…

Astrophysics · Physics 2009-10-31 K. Hirotani

Pulsars are factories of relativistic electrons and positrons that propagate away from the pulsar, permeating later our Galaxy. The acceleration and propagation of these particles are a matter of intense debate. In the last few years, we…

High Energy Astrophysical Phenomena · Physics 2022-02-15 R. López-Coto , E. de Oña Wilhelmi , F. Aharonian , E. Amato , J. Hinton

We explore a non-stationary outer gap scenario for gamma-ray emission process in pulsar magnetosphere. Electrons/positrons that migrate along the magnetic field line and enter the outer gap from the outer/inner boundaries activate the…

High Energy Astrophysical Phenomena · Physics 2015-12-16 J. Takata , C. W. Ng , K. S. Cheng

Fermi LAT has discovered two extended gamma-ray bubbles above and below the galactic plane. We propose that their origin is due to the energy release in the Galactic center (GC) as a result of quasi-periodic star accretion onto the central…

Astrophysics of Galaxies · Physics 2011-09-14 D. O. Chernyshov , K. -S. Cheng , V. A. Dogiel , C. M. Ko , W. -H. Ip , Y. Wang

We compare population synthesis results for inner and outer magnetosphere emission models with the various characteristics measured in the first LAT pulsar catalogue for both the radio-loud and radio-weak or radio-quiet gamma-ray pulsars.…

High Energy Astrophysical Phenomena · Physics 2015-05-27 Marco Pierbattista , Isabelle Grenier , Alice Harding , Peter L. Gonthier

Intriguing sub-TeV tails in the pulsed $\gamma$-ray emission from the Crab pulsar have been recently discovered by the MAGIC and VERITAS Collaborations. They were not clearly predicted by any pulsar model. It is at present argued that this…

High Energy Astrophysical Phenomena · Physics 2016-02-12 W. Bednarek

Enabled by the Fermi Large Area Telescope, we now know young and recycled pulsars fill the gamma-ray sky, and we are beginning to understand their emission mechanism and their distribution throughout the Galaxy. However, key questions…

Soon after the discovery of radio pulsars in 1967, the pulsars are identified as strongly magnetic (typically $10^{12}$G) rapidly rotating ($\sim 10^{2}-0.1$ Hz) neutron stars. However, the mechanism of particle acceleration in the pulsar…

Astrophysics · Physics 2008-11-26 Tomohide Wada , Shinpei Shibata

Studies of Fermi data indicate an excess of GeV gamma rays around the Galactic center (GC), possibly due to dark matter. We show that young gamma-ray pulsars can yield a similar signal. First, a high concentration of GC supernovae naturally…

High Energy Astrophysical Phenomena · Physics 2015-04-15 Ryan M. O'Leary , Matthew D. Kistler , Matthew Kerr , Jason Dexter

Some of the most energetic pulsars exhibit rotation-modulated gamma-ray emission in the $0.1$ to $100$ GeV band. The luminosity of this emission is typically $0.1\text{-}10\%$ of the pulsar spin-down power (gamma-ray efficiency), implying…

High Energy Astrophysical Phenomena · Physics 2023-03-20 Hayk Hakobyan , Alexander Philippov , Anatoly Spitkovsky

We investigate a stationary pair production cascade in the outer magnetosphere of an isolated, spinning neutron star. The charge depletion due to global flows of charged particles, causes a large electric field along the magnetic field…

Astrophysics · Physics 2008-11-26 Kouichi Hirotani

A new model for the high-energy emission from pulsars is developed by considering charged particle motion in the fields of a spinning, highly magnetised and conducting sphere in vacuum. A generally applicable approximation to the particle…

Astrophysics · Physics 2015-06-24 M. G. Higgins , R. N. Henriksen