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Current models of pulsar gamma-ray emission use the magnetic field of a rotating dipole in vacuum as a first approximation to the shape of plasma-filled pulsar magnetosphere. In this paper we revisit the question of gamma-ray light-curve…

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 Fermi Gamma-Ray Space Telescope has discovered many gamma-ray pulsars, both as radio-loud objects and radio-quiet or radio-weak pulsars that have been identified through blind period searches. The latter presumably have gamma-ray beams…

High Energy Astrophysical Phenomena · Physics 2010-02-02 Marco Pierbattista , Isabelle Grenier , Alice Harding , Peter Gonthier

We modelled the radio and gamma-ray light curves of millisecond pulsars using outer gap, two-pole caustic, low-altitude slot gap, and pair-starved polar cap geometric models, combined with a semi-empirical conal radio model. We find that no…

High Energy Astrophysical Phenomena · Physics 2014-11-04 C Venter , TJ Johnson , AK Harding , JE Grove

An interesting new high-energy pulsar sub-population is emerging following early discoveries of gamma-ray millisecond pulsars (MSPs) by the Fermi Large Area Telescope (LAT). We present results from 3D emission modeling, including the…

High Energy Astrophysical Phenomena · Physics 2014-11-20 C. Venter , A. K. Harding , L. Guillemot

The traditional, geometrical rotating vector model (RVM) has proved particularly poor at capturing the polarization sweeps of the young energetic and millisecond pulsars detected by \textit{Fermi}. We augment this model by including finite…

High Energy Astrophysical Phenomena · Physics 2015-06-22 H. A. Craig

The nine millisecond pulsars (MSPs) that have now been detected by Fermi-LAT are providing an excellent opportunity to probe the emission geometry of these ancient compact objects. As they are radio-loud, one may use the relative phase lags…

High Energy Astrophysical Phenomena · Physics 2009-12-15 C. Venter , A. K. Harding , L. Guillemot

We study the pulsar energy-dependent $\gamma$-ray light curves and spectra from curvature radiation in the dissipative magnetospheres. The dissipative magnetospheres with the combined force-free (FFE) and Aristotelian (AE) are computed by a…

High Energy Astrophysical Phenomena · Physics 2024-03-12 Gang Cao , Xiongbang Yang

The GeV light curve of a pulsar is an important probe to detect acceleration regions in its magnetosphere. Motivated by the recent reports on the observations of pulsars by {\it Fermi} Large Area Telescope (LAT), we restudy the two-pole…

High Energy Astrophysical Phenomena · Physics 2014-11-20 J. Fang , L. Zhang

In this work, we introduce the use of the differential geometry Frenet-Serret equations to describe a magnetic line in a pulsar magnetosphere. These equations, which need to be solved numerically, fix the magnetic line in terms of their…

High Energy Astrophysical Phenomena · Physics 2019-10-02 Daniele Viganò , Diego F. Torres

Modeling of the NICER X-ray waveform of the pulsar PSR J0030+0451, aimed to constrain the neutron star mass and radius, has inferred surface hot-spots (the magnetic polar caps) that imply significantly non-dipolar magnetic fields. To this…

High Energy Astrophysical Phenomena · Physics 2021-02-10 Constantinos Kalapotharakos , Zorawar Wadiasingh , Alice K. Harding , Demosthenes Kazanas

Pulsed gamma rays have been detected with the Fermi Large Area Telescope (LAT) from more than 20 millisecond pulsars (MSPs), some of which were discovered in radio observations of bright, unassociated LAT sources. We have fit the radio and…

High Energy Astrophysical Phenomena · Physics 2011-11-04 Tyrel J. Johnson , Alice K. Harding , Christo Venter

We explore the multiwavelength radiation properties of the light curves and energy spectra in the dissipative magnetospheres of pulsars. The dissipative magnetospheres are simulated by the pseudo-spectral method with the combined force-free…

High Energy Astrophysical Phenomena · Physics 2024-03-12 Xiongbang Yang , Gang Cao

Fermi Large Area Telescope (LAT) has recently detected 8 gamma-ray millisecond pulsars (MSPs), providing an unprecedented opportunity to probe the magnetospheres of these low-spin-down pulsars. We performed 3D emission modeling, including…

High Energy Astrophysical Phenomena · Physics 2009-11-26 C. Venter , A. K. Harding , L. Guillemot

The Fermi Large Area Telescope (LAT) has recently reported the detection of pulsed gamma-rays from 6 young pulsars (J0631+1036, J0659+1414, J0742-2822, J1420-6048, J1509-5850, and J1718-3825), all exhibiting single-peaked pulse profiles…

High Energy Astrophysical Phenomena · Physics 2011-05-23 A. S. Seyffert , C. Venter , O. C. de Jager , A. K. Harding

Since its launch in 2008, the Fermi Large Area Telescope (LAT) has detected over 200 -ray pulsars above 100 MeV. This population of pulsars is characterised by a rich diversity of light curve morphologies. Researchers have been using both…

High Energy Astrophysical Phenomena · Physics 2017-12-25 M. C. Bezuidenhout , C. Venter , A. S. Seyffert , A. K. Harding

Radio polarization measurements of pulsed emission from pulsars offer a valuable insight into the basic geometry of the neutron star: inclination angle between the magnetic and rotation axis and inclination of the line of sight. So far, all…

High Energy Astrophysical Phenomena · Physics 2017-01-11 J. Pétri

We previously obtained constraints on the viewing geometries of 6 Fermi LAT pulsars using a multiwavelength approach (Seyffert et al., 2011). To obtain these constraints we compared the observed radio and $\gamma$-ray light curves (LCs) for…

High Energy Astrophysical Phenomena · Physics 2015-01-28 A. S. Seyffert , C. Venter , T. J. Johnson , A. K. Harding

Multi-wavelength observations of pulsar emission properties are powerful means to constrain their magnetospheric activity and magnetic topology. Usually a star centred magnetic dipole model is invoked to explain the main characteristics of…

High Energy Astrophysical Phenomena · Physics 2020-01-08 Jérôme Pétri , Dipanjan Mitra

We explore the emission properties of a dissipative pulsar magnetosphere model introduced by Kalapotharakos et al. (2014), comparing its high energy light curves and spectra, due to curvature radiation, with data collected by the Fermi LAT.…

High Energy Astrophysical Phenomena · Physics 2015-05-20 Gabriele Brambilla , Constantinos Kalapotharakos , Alice K. Harding , Demosthenes Kazanas