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Related papers: The dispersion in pulsar $\gamma$-ray efficiency

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There is active interest in the extent to which unresolved gamma-ray pulsars contribute to the galactic diffuse emission, and whether unresolved gamma-ray pulsars could be responsible for the excess of diffuse galactic emission above 1 GeV…

Astrophysics · Physics 2007-05-23 Martin Pohl , Gottfried Kanbach , Stan D. Hunter , Brian B. Jones

Radio emission propagating over an Earth-pulsar line of sight provides a unique probe of the intervening ionized interstellar medium (ISM). Variations in the integrated electron column density along this line of sight, or dispersion measure…

High Energy Astrophysical Phenomena · Physics 2020-04-08 M. T. Lam , T. J. W. Lazio , T. Dolch , M. L. Jones , M. A. McLaughlin , D. R. Stinebring , M. Surnis

Pulsar radio emission undergoes dispersion due to the presence of free electrons in the interstellar medium (ISM). The dispersive delay in the arrival time of pulsar signal changes over time due to the varying ISM electron column density…

We present a model for the gamma-ray emission of pulsars in terms of curvature radiation by highly relativistic particles. It is shown that the injection of power-law primary particles from an outer gap and subsequent cooling by curvature…

Astrophysics · Physics 2007-05-23 A. R. Crusius-Waetzel , H. Lesch

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

The turbulent ionized interstellar medium diffracts radio waves and makes them propagate in multiple paths. The pulse-broadening observed at low frequencies results from the scattering effect of interstellar clouds of ionized gas. During…

High Energy Astrophysical Phenomena · Physics 2025-06-18 W. C. Jing , J. L. Han , C. Wang , P. F. Wang , T. Wang , N. N. Cai , J. Xu , Z. L. Yang , D. J. Zhou , Yi Yan , W. Q. Su , X. Y. Gao , L. Xie

Dispersion in the interstellar medium is a well known phenomenon that follows a simple relationship, which has been used to predict the time delay of dispersed radio pulses since the late 1960s. We performed wide-band simultaneous…

From the hundreds of gamma-ray pulsars known, only a handful show non-thermal X-ray pulsations. Instead, nine objects pulse in non-thermal X-rays but lack counterparts at higher energies. Here, we present a physical model for the…

High Energy Astrophysical Phenomena · Physics 2018-02-13 Diego F. Torres

Pulsars' gamma-ray luminosities are thought to exceed their radio luminosities by several orders of magnitude: a notion that is based on the assumption that the decay with distance of the flux of gamma-ray pulses obeys the inverse-square…

High Energy Astrophysical Phenomena · Physics 2022-01-25 Houshang Ardavan

We present simulations of scattering phenomena which are important in pulsar observations, but which are analytically intractable. The simulation code, which has also been used for solar wind and atmospheric scattering problems, is…

Astrophysics of Galaxies · Physics 2015-05-19 W. A. Coles , B. J. Rickett , J. J. Gao , G. Hobbs , J. P. W. Verbiest

The popular outer gap model of magnetospheric emission from pulsars has been widely applied to explain the properties observed in $\gamma$-rays. However, its quantitative predictions rely on a number of approximations and assumptions that…

High Energy Astrophysical Phenomena · Physics 2014-12-05 Daniele Viganò , Diego F. Torres , Kouichi Hirotani , Martín E. Pessah

We compute the variation of the beaming fraction with the efficiency of high energy gamma-ray production in the outer gap pulsar model of Romani and Yadigaroglu. This allows us to correct the fluxes observed for pulsars in the EGRET band…

Astrophysics · Physics 2009-10-22 I. -A. Yadigaroglu , Roger W. Romani

The velocity and density distribution of $e^\pm$ in the pulsar wind are crucial distinction among magnetosphere models, and contains key parameters determining the high energy emission of pulsar binaries. In this work, a direct method is…

High Energy Astrophysical Phenomena · Physics 2017-10-11 Shu-Xu Yi , K. S. Cheng

Pulsars play a crucial astrophysical role as the highly energetic compact radio, X-ray, and gamma-ray sources. Our previous works show that the radio pulsars found as the pulsing gamma sources by the Large Area Telescope (LAT) on the board…

High Energy Astrophysical Phenomena · Physics 2018-08-29 I. F. Malov , M. A. Timirkeeva

Pulsar efficiency, defined as the ratio of the pulsed bolometric luminosity to the spin-down power, is calculated to be about 15% (averaged over the spin-dipole inclination angle, ranging between about 50% for the aligned and 10% for the…

High Energy Astrophysical Phenomena · Physics 2012-09-25 Andrei Gruzinov

Radio signals are delayed when propagating through plasma. This type of delay is frequency-dependent and is usually used for estimating the projected number density of electrons along the line of sight, called the dispersion measure. The…

High Energy Astrophysical Phenomena · Physics 2020-02-12 Xinzhong Er , Yuanpei Yang , Adam Rogers

Observations of pulsars across the radio spectrum are revealing a dependence of the characteristic scattering time ($\tau$) on frequency, which is more complex than the simple power law with a theoretically predicted power law index. In…

High Energy Astrophysical Phenomena · Physics 2021-02-04 Marisa Geyer , Aris Karastergiou

We show that the $\gamma$-ray pulsar observables, i.e., their total $\gamma$-ray luminosity, $L_{\gamma}$, spectral cut-off energy, $\epsilon_{\rm cut}$, stellar surface magnetic field, $B_{\star}$, and spin-down power $\dot{\mathcal{E}}$,…

High Energy Astrophysical Phenomena · Physics 2019-09-25 Constantinos Kalapotharakos , Alice K. Harding , Demosthenes Kazanas , Zorawar Wadiasingh

We use Bayesian methods to analyze the distribution of gamma ray burst intensities reported in the Third BATSE Catalog (3B catalog) of gamma ray bursts, presuming the distribution of burst sources (``bursters'') is isotropic. We study both…

Astrophysics · Physics 2009-10-30 Thomas J. Loredo , Ira M. Wasserman

A pulsar's pulse profile gets broadened at low frequencies due to dispersion along the line of sight or due to multi-path propagation. The dynamic nature of the interstellar medium makes both of these effects time-dependent and introduces…

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