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Related papers: Pulsar Pair Cascades in Magnetic Fields with Offse…

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We report on the first self-consistent multidimensional particle-in-cell numerical simulations of non-homogeneous pair discharges in polar caps of rotation-powered pulsars. By introducing strong inhomogeneities in the initial plasma…

High Energy Astrophysical Phenomena · Physics 2024-09-25 Alexander Chernoglazov , Alexander Philippov , Andrey Timokhin

Using an analytic, axisymmetric approach that includes general relativity, coupled to a condition for pair production deduced from simulations, we derive general results about the spatial distribution of pair-producing field lines over the…

High Energy Astrophysical Phenomena · Physics 2016-10-26 Mikhail A. Belyaev , Kyle Parfrey

We present first-principles relativistic particle-in-cell simulations of the oblique pulsar magnetosphere with pair formation. The magnetosphere starts to form with particles extracted from the surface of the neutron star. These particles…

High Energy Astrophysical Phenomena · Physics 2015-06-23 Alexander A. Philippov , Anatoly Spitkovsky , Benoit Cerutti

Development of QED cascades in a standing electromagnetic wave for circular and linear polarizations is simulated numerically with a 3D PIC-MC code. It is demonstrated that for the same laser energy the number of particles produced in a…

Plasma Physics · Physics 2013-10-16 V. F. Bashmakov , E. N. Nerush , I. Yu. Kostyukov , A. M. Fedotov , N. B. Narozhny

The magnetic field topology in the surrounding of neutron stars is one of the key questions in pulsar magnetospheric physics. A very extensive literature exists about the assumption of a dipolar magnetic field but very little progress has…

High Energy Astrophysical Phenomena · Physics 2015-06-24 Jerome Petri

In the canonical model of a pulsar, rotational energy is transmitted through the surrounding plasma via two electrical circuits, each connecting to the star over a small region known as a "polar cap." For a dipole-magnetized star, the polar…

High Energy Astrophysical Phenomena · Physics 2018-01-03 Samuel E. Gralla , Alexandru Lupsasca , Alexander Philippov

We numerically model evolution of magnetic fields inside a neutron star under the influence of ambipolar diffusion in the weak-coupling mode in the one-fluid MHD approximation. Our simulations are three-dimensional and performed in…

High Energy Astrophysical Phenomena · Physics 2022-11-09 Andrei P. Igoshev , Rainer Hollerbach

Soft X-ray emission from neutron stars affords powerful diagnostic tools for uncovering their surface and interior properties, as well as their geometric configurations. In the atmospheres of neutron stars, the presence of magnetic fields…

High Energy Astrophysical Phenomena · Physics 2025-10-29 Hoa Dinh Thi , Matthew G. Baring , Kun Hu , Alice K. Harding , Joseph A. Barchas

For sufficiently strong magnetic fields and/or low temperatures, the neutron star surface may be in a condensed state with little gas or plasma above it. Such surface condensation can significantly affect the thermal emission from isolated…

Astrophysics · Physics 2012-07-31 Zach Medin , Dong Lai

Over the last four decades, persistent and flaring emission of magnetars observed by various telescopes has provided us with a suite of light curves and spectra in soft and hard X-rays, with no emission yet detected above around 1 MeV.…

High Energy Astrophysical Phenomena · Physics 2019-04-17 Kun Hu , Matthew G. Baring , Zorawar Wadiasingh , Alice K. Harding

Pulsar magnetospheres are thought to be filled with electron-positron plasma generated in pair cascades. The driving mechanism of these cascades is the emission of gamma-ray photons and their conversion into pairs via Quantum…

High Energy Astrophysical Phenomena · Physics 2021-09-30 Fábio Cruz , Thomas Grismayer , Alexander Y. Chen , Anatoly Spitkovsky , Luis O. Silva

Despite the fact that pulsars have been observed for almost half a century, many questions have remained unanswered. We use the analysis of X-ray observations in order to study the polar cap region of radio pulsars. The size of the hot…

High Energy Astrophysical Phenomena · Physics 2013-04-19 Andrzej Szary

Off-centred dipole configurations have been suggested to explain different phenomena in neutron stars, such as natal kicks, irregularities in polarisation of radio pulsars and properties of X-ray emission from millisecond pulsars. Here for…

High Energy Astrophysical Phenomena · Physics 2023-08-21 Andrei P. Igoshev , Rainer Hollerbach , Toby Wood

We study theoretical X-ray light curves and polarization properties of accretion-powered millisecond pulsars. We assume that the radiation is produced in two antipodal spots at the neutron star surface which are associated with the magnetic…

Astrophysics · Physics 2009-11-10 Kerttu Viironen , Juri Poutanen

We present numerical simulations of the electron-positron plasma creation process in a simple neutron star magnetosphere. We have developed a set of cascade `kernels', which represent the endpoint of the pair cascades resulting from…

Astrophysics · Physics 2009-11-07 Paul N. Arendt , Jean A. Eilek

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

Pulsars, or more generally rotation powered neutron stars, are excellent factories of antimatter in the Galaxy, in the form of pairs of electrons and positrons. Electrons are initially extracted from the surface of the star by the intense…

High Energy Astrophysical Phenomena · Physics 2010-07-28 Pasquale Blasi , Elena Amato

Here we briefly report on first results of self-consistent simulation of non-stationary electron-positron cascades in the polar cap of pulsar using specially developed hybrid PIC/Monte-Carlo numerical code. We consider the case of…

High Energy Astrophysical Phenomena · Physics 2009-12-31 A. N. Timokhin

Extremely strong magnetic fields change the vacuum index of refraction. Although this polarization dependent effect is small for typical neutron stars, it is large enough to decouple the polarization states of photons traveling within the…

Astrophysics · Physics 2009-10-31 Jeremy S. Heyl , Nir J. Shaviv

We use Monte Carlo approach to study the energetics of electrons accelerated in a pulsar polar gap. As energy-loss mechanisms we consider magnetic Compton scattering of thermal X-ray photons and curvature radiation. The results are compared…

Astrophysics · Physics 2007-05-23 J. Dyks , B. Rudak