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Related papers: The Geminga Fraction

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Recent optical/UV data of Geminga (Mignani et al. 1998) have strengthen the significance of the emission feature present over the thermal continuum best fitting the EUV/soft X-ray data. Here we present a phenomenological model interpreting…

Astrophysics · Physics 2007-05-23 A. Jacchia , F. De Luca , E. Lazzaro , P. A. Caraveo , R. P. Mignani , G. F. Bignami

In the canonical picture of pulsars, radio emission arises from a narrow cone centered on the star's magnetic axis but many basic details remain unclear. We use high-quality polarization data taken with the Parkes radio telescope to…

High Energy Astrophysical Phenomena · Physics 2019-11-06 Simon Johnston , Michael Kramer

We present results of Compton Gamma-Ray Observatory EGRET observations of the unidentified high-energy gamma-ray sources 2EG J1049-5847 (GEV J1047-5840, 3EG J1048-5840) and 2EG J1103-6106 (3EG J1102-6103). These sources are spatially…

Astrophysics · Physics 2009-10-31 V. M. Kaspi , J. R. Lackey , J. Mattox , R. N. Manchester , M. Bailes , R. Pace

The HAWC Collaboration has discovered a $\gamma$-ray emission extended about 2 degrees around the Geminga and Monogem pulsar wind nebulae (PWNe) at $\gamma$-ray energies $E_\gamma >5$ TeV. We analyze, for the first time, almost 10 years of…

High Energy Astrophysical Phenomena · Physics 2019-12-25 Mattia Di Mauro , Silvia Manconi , Fiorenza Donato

Geminga pulsar is surrounded by a multi-TeV $\gamma$-ray halo radiated by the high energy electrons and positrons accelerated by the central pulsar wind nebula (PWN). The angular profile of the $\gamma$-ray emission reported by HAWC…

High Energy Astrophysical Phenomena · Physics 2019-08-07 Kun Fang , Xiao-Jun Bi , Peng-Fei Yin

We report unsuccessful searches for pulsations from the neutron star RX J1836.2+5925 identified with the EGRET source 3EG J1835+5918. A 24 hr observation with the NRAO Green Bank Telescope at 820 MHz placed an upper limit on flux density of…

Astrophysics · Physics 2009-11-13 J. P. Halpern , F. Camilo , E. V. Gotthelf

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

A year after \emph{Fermi} was launched, the number of known gamma-ray pulsars has increased dramatically. For the first time, a sizable population of pulsars has been discovered in gamma-ray data alone. For the first time, millisecond…

High Energy Astrophysical Phenomena · Physics 2009-12-21 L. Guillemot , Fermi LAT Collaboration

Lyne & Manchester (1988) identified a group of some 50 pulsars they called "partial cones" which they found difficult to classify and interpret. They were notable for their asymmetric average profiles and asymmetric polarization…

Astrophysics of Galaxies · Physics 2015-05-20 Dipanjan Mitra , Joanna. M. Rankin

We have developed a method to compute the possible distribution of radio emission regions in a typical pulsar magnetosphere, taking into account the viewing geometry and rotational effects of the neutron star. Our method can estimate the…

Astrophysics of Galaxies · Physics 2015-05-18 R. M. C. Thomas , Y. Gupta , R. T. Gangadhara

We present a model to explain the decrease in the amplitude of the pulse profile with increasing energy observed in Geminga's soft X-ray surface thermal emission. We assume the presence of plates surrounded by a surface with very distinct…

Astrophysics · Physics 2016-08-15 Dany Page , Yu. A. Shibanov , V. E. Zavlin

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 2nd Fermi-LAT pulsar catalog includes 117 gamma-ray pulsars, of which roughly one third are millisecond pulsars (MSPs) while the remaining two thirds split evenly into young radio-loud and radio-quiet pulsars. Although this large…

High Energy Astrophysical Phenomena · Physics 2015-06-12 Matthew Kerr , the Fermi-LAT Collaboration

We apply a likelihood analysis to pulsar detections, pulsar upper limits, and diffuse background measurements from the OSSE and EGRET instruments on the Compton Gamma Ray Observatory to constrain the luminosity law for gamma-ray pulsars and…

Astrophysics · Physics 2009-10-31 M. A. McLaughlin , J. M. Cordes

We discuss $\gamma$-ray emissions from the outer gap accelerators of middle-aged pulsars for part of the series of our studies. A two-dimensional electrodynamic model is used to solve the distribution of accelerating electric fields with…

Astrophysics · Physics 2009-11-13 J. Takata , H. -K. Chang

We have performed a Monte-Calro simulation for Galactic population of pulsars and for the $\gamma$-ray observations. We apply outer gap model for the $\gamma$-ray emission process, and study the radiation characteristics as a function of…

High Energy Astrophysical Phenomena · Physics 2015-05-27 J. Takata , Y. Wang , K. S. Cheng

We study the $\gamma$-ray emission from the pulsar magnetosphere based on outer gap models, and the TeV radiation from pulsar wind nebulae (PWNe) through inverse Compton scattering using a one-zone model. We showed previously that GeV…

Astrophysics · Physics 2009-11-10 W. Wang , Z. J. Jiang , C. S. J. Pun , K. S. Cheng

We present pulsar emission beam analyses and models in an effort to examine pulsar geometry and physics at the lowest frequencies scattering permits. We consider two populations of well-studied pulsars that lie outside the Arecibo sky, the…

High Energy Astrophysical Phenomena · Physics 2022-06-17 Joanna M. Rankin

Most pulsars observed by the Fermi LAT have gamma-ray luminosities scaling with spindown power Edot as L_gamma (Edot x 10^33 erg/s)^{1/2}. However, there exist one detection and several upper limits an order of magnitude or more fainter…

High Energy Astrophysical Phenomena · Physics 2015-05-28 R. W. Romani , M. Kerr , H. A. Craig , S. Johnston , I. Cognard , D. A. Smith

Geminga is a nearby (250 pc) middle-aged (spin-down time scale ~12,000 years) pulsar associated with a supernova remnant. Geminga has been a prime candidate for the origin of the unexpectedly high flux of cosmic-ray positrons above 10 GeV…

High Energy Astrophysical Phenomena · Physics 2019-08-16 A. U. Abeysekara
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