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Using the outer gap model, we investigate the emission region for the multi-wavelength light curve from energetic pulsars. We assume that gamma-ray and non-thermal X-ray photons are emitted from a particle acceleration region in the outer…

High Energy Astrophysical Phenomena · Physics 2015-05-28 Shota Kisaka , Yasufumi Kojima

The gamma-ray energy range from a few hundred keV to a few hundred MeV has remained largely unexplored, mainly due to the challenging nature of the measurements, since the pi- oneering, but limited, observations by COMPTEL on the Compton…

The X-ray and gamma-ray spectrum of rotation-powered millisecond pulsars is investigated in a model for acceleration and pair cascades on open field lines above the polar caps. Although these pulsars have low surface magnetic fields, their…

Astrophysics · Physics 2016-08-30 Alice K. Harding , Vladimir V. Usov , Alex G. Muslimov

We discuss a possible scenario for radiation mechanism of pulsed GeV gamma-rays from magnetars. The magnetars have shown frequent X-ray bursts, which would be triggered by crust fractures and could release the energy of order of…

High Energy Astrophysical Phenomena · Physics 2015-06-15 J. Takata , Y. Wang , E. M. H. Wu , K. S. Cheng

The Fermi satellite has detected GeV emission from a number of gamma-ray bursts and active galactic nuclei at high redshift, z > 1.5. We examine the constraints that the detections of gamma rays from several of these sources place on the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Rudy C. Gilmore

The Fermi Large Area Telescope has detected over 260 gamma-ray pulsars. About one quarter of these are labeled as radio-quiet. In the population of nonrecycled gamma-ray pulsars, the fraction of radio-quiet pulsars is higher, about one…

High Energy Astrophysical Phenomena · Physics 2021-10-13 J. -M. Grießmeier , D. A. Smith , G. Theureau , T. J. Johnson , M. Kerr , L. Bondonneau , I. Cognard , M. Serylak

Gamma-ray emission from pulsars is thought to arise from accelerating regions in pulsar's outer magnetosphere. The shape of the light curves is thus sensitive to the details of the magnetic geometry of the magnetosphere. In this work, we…

High Energy Astrophysical Phenomena · Physics 2009-11-03 Xue-Ning Bai , Anatoly Spitkovsky

The Vela pulsar is the brightest persistent source in the GeV sky and thus is the traditional first target for new gamma-ray observatories. We report here on initial Fermi Large Area Telescope observations during verification phase pointed…

Astrophysics · Physics 2009-11-13 A. A. Abdo

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

Observations by the Fermi Large Area Telescope of gamma-ray millisecond pulsar light curves imply copious pair production in their magnetospheres, and not exclusively in those of younger pulsars. Such pair cascades may be a primary source…

High Energy Astrophysical Phenomena · Physics 2015-07-15 C. Venter , A. Kopp , A. K. Harding , P. L. Gonthier , I. Büsching

We use a simple two-layer outer gap model, whose accelerator consists of a primary region and a screening region, to discuss $\gamma$-ray spectrum of mature pulsars detected by $Fermi$. By solving the Poisson equation with an assumed simple…

High Energy Astrophysical Phenomena · Physics 2015-05-19 Y. Wang , J. Takata , K. S. Cheng

Despite the diversity and energy dependence of $\gamma$-ray pulse morphologies in Crab, Vela and Dragonfly, the phaseograms of these three canonical young pulsars can be organised within a single four-beam geometric template. Using…

High Energy Astrophysical Phenomena · Physics 2026-05-06 Paul K. H. Yeung , Takayuki Saito

The highly luminous and variable prompt emission in Gamma-Ray Bursts (GRBs) arises in an ultra-relativistic outflow. The exact underlying radiative mechanism shaping its non-thermal spectrum is still uncertain, making it hard to determine…

High Energy Astrophysical Phenomena · Physics 2018-01-31 Ramandeep Gill , Jonathan Granot

Significant gamma-ray pulsations have been detected from ~40 millisecond pulsars (MSPs) using 3 years of sky-survey data from the Fermi LAT and radio timing solutions from across the globe. We have fit the radio and gamma-ray pulse profiles…

High Energy Astrophysical Phenomena · Physics 2019-08-14 T. J. Johnson , A. K. Harding , C. Venter , J. E. Grove

Diffuse TeV emission has been observed by H.E.S.S. in the Galactic Center region, in addition to the GeV gamma rays observed by Fermi. We propose that a population of unresolved millisecond pulsars located around the Galactic Center,…

High Energy Astrophysical Phenomena · Physics 2018-08-08 Claire Guépin , Lucia Rinchiuso , Kumiko Kotera , Emmanuel Moulin , Tanguy Pierog , Joseph Silk

In the framework of the three-dimensional (3D) annular gap model with reasonable parameters (the magnetic inclination angle \alpha = 45 deg and the view angle \zeta = 63 deg), we first use the latest hight energy data to self-consistently…

High Energy Astrophysical Phenomena · Physics 2012-03-16 YuanJie Du , GuoJun Qiao , Wei Wang

Gamma-ray data from the Fermi-Large Area Telescope reveal an unexplained, apparently diffuse, signal from the Galactic bulge that peaks near 2 GeV with an approximately spherical intensity profile $\propto r^{-2.4}$ that extends to angular…

High Energy Astrophysical Phenomena · Physics 2022-05-03 Anuj Gautam , Roland M. Crocker , Lilia Ferrario , Ashley J. Ruiter , Harrison Ploeg , Chris Gordon , Oscar Macias

We report the detection of pulsed gamma-rays for PSRs J0631+1036, J0659+1414, J0742-2822, J1420-6048, J1509-5850 and J1718-3825 using the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope (formerly known as GLAST).…

Solar and Stellar Astrophysics · Physics 2010-01-06 The Fermi LAT collaboration , the Fermi Pulsar Timing Consortium

A model of fast radio bursts, which enlists young, short period extragalactic magnetars satisfying $B/P > 2 \times 10^{16}$~G~s$^{-1}$ (1~G = 1~statvolt~cm$^{-1}$) as the source, is proposed. When the parallel component $\bE_\parallel$ of…

High Energy Astrophysical Phenomena · Physics 2017-01-18 Richard Lieu

The Large Area Telescope (LAT) on board the Fermi satellite has detected ~120 pulsars above 100 MeV. While most gamma-ray pulsars have spectra that are well modeled by a power law with an exponential cut-off at around a few GeV, some show…

High Energy Astrophysical Phenomena · Physics 2019-08-13 Pablo M. Saz Parkinson