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

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To illustrate the standard candle property of gamma-ray pulsars (and also to thereby confirm the recent first-principle calculation of pulsar gamma-ray emission), we "measure", via the lightcurve fitting, three distances and one moment of…

High Energy Astrophysical Phenomena · Physics 2013-10-22 Andrei Gruzinov

Radio pulses from pulsars are affected by plasma dispersion, which results in a frequency-dependent propagation delay. Variations in the magnitude of this effect lead to an additional source of red noise in pulsar timing experiments,…

We analyze pulsar fluxes at 1400 MHz ($S_{1400}$) and distances ($d$) extracted from the Parkes Multibeam Survey. Under the assumption that distribution of pulsar luminosities is distance-independent, we find that either (a) pulsar fluxes…

Interstellar scattering causes pulsar profiles to grow asymmetrically, thus affecting the pulsar timing residuals, and is strongest at lower frequencies. Different Interstellar medium models predict different frequency ($\nu$) and…

High Energy Astrophysical Phenomena · Physics 2019-05-01 Karishma Bansal , G. B. Taylor , Kevin Stovall , Jayce Dowell

We analyze deterministic and random temporal variations in dispersion measure (DM) from the full three-dimensional velocities of pulsars with respect to the solar system, combined with electron-density variations on a wide range of length…

High Energy Astrophysical Phenomena · Physics 2016-09-29 Michael T. Lam , James M. Cordes , Shami Chatterjee , Megan L. Jones , Maura A. McLaughlin , John W. Armstrong

Distance measurements of gamma-ray pulsars are challenging questions in present pulsar studies. The Large Area Telescope (LAT) aboard the Fermi gamma-ray observatory discovered more than 70 gamma-ray pulsars including 24 new gamma-selected…

High Energy Astrophysical Phenomena · Physics 2015-05-27 W. Wang

We compare radio profile widths of young, energetic gamma-ray-detected and non-gamma-ray-detected pulsars. We find that the latter typically have wider radio profiles, with the boundary between the two samples exhibiting a dependence on the…

High Energy Astrophysical Phenomena · Physics 2016-11-15 Simon C. Rookyard , Patrick Weltevrede , Simon Johnston , Matthew Kerr

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

Context: GeV gamma-ray pulsations from over 140 pulsars have been characterized using the Fermi Large Area Telescope, enabling improved understanding of the emission regions within the neutron star magnetospheres, and the contributions of…

Taking advantage of the high sensitivity of the Chandra Advanced CCD Imaging Spectrometer, we have conducted a snap-shot survey of pulsars previously undetected in X-rays. We detected 12 pulsars and established deep flux limits for 11…

High Energy Astrophysical Phenomena · Physics 2015-06-04 Oleg Kargaltsev , Martin Durant , George G. Pavlov , Gordon Garmire

The dispersion measure (DM) is one of the key attributes of radio pulsars and Fast Radio Bursts (FRBs). There is a mistaken view that the DM is an accurate measure of the column density of electrons between the observer and the source. To…

High Energy Astrophysical Phenomena · Physics 2020-07-07 S. R. Kulkarni

We theoretically analyze diffusion trajectories of an anisotropic object moving on a two dimensional space in the absence of an external field. In determining diffusion parameters associated with the shape anisotropy, we devise a measure…

Statistical Mechanics · Physics 2015-08-31 Sunghan Roh , Juyeon Yi , Yong Woon Kim

We use VLBA+VLA observations to measure the sizes of the scatter-broadened images of 6 of the most heavily scattered known pulsars: 3 within the Galactic Centre (GC) and 3 elsewhere in the inner Galactic plane. By combining the measured…

Astrophysics of Galaxies · Physics 2017-08-30 J. Dexter , A. Deller , G. C. Bower , P. Demorest , M. Kramer , B. W. Stappers , A. G. Lyne , M. Kerr , L. G. Spitler , D. Psaltis , M. Johnson , R. Narayan

Theoretical models and experimental observations suggest that gamma-ray bursts (GRB) and high-energy neutrino bursts travelling through the interstellar space may reach the Earth at different speeds. We propose and study in details the…

High Energy Astrophysical Phenomena · Physics 2021-10-29 Iver Brevik , Masud Chaichian , Markku Oksanen

Because of the relatively broad angular resolution of current gamma-ray instruments in the MeV-GeV energy range, the photons of a given source are mixed with those coming from nearby sources or diffuse background. This source confusion…

Instrumentation and Methods for Astrophysics · Physics 2019-02-06 P. Bruel

We perform global particle-in-cell simulations of pulsar magnetospheres including pair production, ion extraction from the surface, frame dragging corrections, and high energy photon emission and propagation. In the case of oblique…

High Energy Astrophysical Phenomena · Physics 2018-03-28 Alexander A. Philippov , Anatoly Spitkovsky

The prevalent view that the radio-loud gamma-ray pulsars have gamma-ray luminosities that exceed their radio luminosities by several orders of magnitude is based on the assumption that the decay with distance of their gamma-ray fluxes obeys…

High Energy Astrophysical Phenomena · Physics 2023-03-02 Houshang Ardavan

Our understanding of the universe relies mostly on electromagnetism. As photons are the messengers, fundamental physics is concerned in testing their properties. Photon mass upper limits have been earlier set through pulsar observations,…

Instrumentation and Methods for Astrophysics · Physics 2016-12-30 Mark J. Bentum , Luca Bonetti , Alessandro D. A. M. Spallicci

Here we investigate to what extent unresolved \gr pulsars contribute to the galactic diffuse emission, and further whether unresolved \gr pulsars can be made responsible for the excess of diffuse galactic emission above 1 GeV which has been…

Astrophysics · Physics 2009-10-30 Martin Pohl

It is difficult to discover pulsars via their gamma-ray emission because current instruments typically detect fewer than one photon per million rotations. This creates a significant computing challenge for isolated pulsars, where the…

High Energy Astrophysical Phenomena · Physics 2020-10-23 L. Nieder , B. Allen , C. J. Clark , H. J. Pletsch