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We present a systematic study of particle transport by diffusion in young pulsar wind nebulae (PWNe). We selected nine bright sources that are well resolved with the Chandra X-ray Observatory. We analyzed archival data to obtain their…

High Energy Astrophysical Phenomena · Physics 2022-03-14 Chin-Ping Hu , Wataru Ishizaki , C. -Y. Ng , Shuta J. Tanaka , Y. -L. Mong

Pulsar wind nebulae (PWNe), formed when the wind originating from a rapidly rotating neutron star flows out into its surroundings, have now been observed across the electromagnetic spectrum from the radio to the PeV gamma-ray regime. For…

High Energy Astrophysical Phenomena · Physics 2026-03-19 Alison M. W. Mitchell , Samuel T. Spencer

High-energy particle transport in pulsar wind nebulae (PWNe) plays an essential role in explaining the characteristics revealed in multiwavelength observations. In this paper, the TeV-gamma-ray-emitting electrons in the Vela X PWN are…

High Energy Astrophysical Phenomena · Physics 2019-07-04 Yiwei Bao , Siming Liu , Yang Chen

We study the transport of high-energy particles in pulsar wind nebulae (PWN) using three-dimensional MHD (see Porth et al. (2014) for details) and test-particle simulations, as well as a Fokker-Planck particle transport model. The latter…

High Energy Astrophysical Phenomena · Physics 2016-07-27 O. Porth , M. J. Vorster , M. Lyutikov , N. E. Engelbrecht

In the last decade, ground-based Imaging Atmospheric Cherenkov Telescopes have discovered about 175 very-high-energy (VHE; $E >$ 100 GeV) gamma-ray sources, with more to follow with the development of H.E.S.S. II and CTA. Nearly 40 of these…

High Energy Astrophysical Phenomena · Physics 2018-02-02 Carlo van Rensburg , Christo Venter , Paulus Kruger

Using the Australia Telescope Compact Array (ATCA) we have imaged the fields around five promising pulsar candidates to search for radio pulsar wind nebulae (PWNe). We have used the ATCA in its pulsar gating mode; this enables an image to…

Astrophysics · Physics 2009-10-31 B. W. Stappers , B. M. Gaensler , S. Johnston

Estimating the cosmic-ray acceleration efficiency $ \epsilon $ in supernova remnants (SNRs) through observations is a challenging task in general. Based on the Rankine-Hugoniot shock conditions, we find an anticorrelation between $ \epsilon…

High Energy Astrophysical Phenomena · Physics 2018-12-21 Yiran Zhang , Siming Liu

We present preliminary results from a systematic spectral study of pulsars and their wind nebulae using the Chandra X-Ray Observatory. The superb spatial resolution of Chandra allows us to differentiate the compact object's spectrum from…

Astrophysics · Physics 2007-05-23 E. V. Gotthelf , C. M. Olbert

Pulsar Wind Nebulae (PWNe), structures powered by energetic pulsars, are known for their detection across the entire electromagnetic spectrum, with diverse morphologies and spectral behaviour between these bands. The temporal evolution of…

High Energy Astrophysical Phenomena · Physics 2023-04-05 A. M. W. Mitchell , J. Gelfand

The propagation of a shock wave into a medium is expected to heat the material beyond the shock, producing noticeable effects in intensity line ratios such as [O III]/Halpha. To investigate the occurrence of shocks in planetary nebulae…

Solar and Stellar Astrophysics · Physics 2015-06-16 M. A. Guerrero , J. A. Toalá , J. J. Medina , V. Luridiana , L. F. Miranda , A. Riera , P. F. Velázquez

A major attraction of diffusive shock acceleration is the prediction of power-law spectra for energetic particle distributions. However, this property is not fundamental to the theory. We demonstrate that for planar shocks with an oblique…

High Energy Astrophysical Phenomena · Physics 2025-11-04 Asma Shirin T , Brian Reville , Nils W. Schween , Florian Schulze , John G. Kirk

We have observed pulsar wind nebulae in the three supernova remnants G11.2-0.3, G16.7+0.1, and G29.7-0.3 at 89 GHz with the Berkeley-Illinois-Maryland Association Array, measuring total flux densities of two of them for comparison with…

Astrophysics · Physics 2009-11-10 D. C. -J. Bock , B. M. Gaensler

We review recent theoretical developments on pulsar winds, their nebulae and relativistic shock acceleration, and show how they illuminate unsolved problems in plerion spectra, in particular the multiple spectral breaks in the Crab and the…

Astrophysics · Physics 2007-05-23 Yves A. Gallant , Eric van der Swaluw , John G. Kirk , Abraham Achterberg

In a recent work, we numerically studied the radiative properties of the reverberation phase of pulsar wind nebulae (PWNe), i.e., when the reverse shock created by the supernova explosion travels back towards the pulsar, compressing the…

High Energy Astrophysical Phenomena · Physics 2019-04-10 Diego F. Torres , Tingting Lin , Francesco Coti Zelati

Pulsar wind nebulae (PWNe) are suggested to be acceleration sites of cosmic rays in the Galaxy. While the magnetic field plays an important role in the acceleration process, previous observations of magnetic field configurations of PWNe are…

High Energy Astrophysical Phenomena · Physics 2016-04-06 Y. K. Ma , C. -Y. Ng , N. Bucciantini , P. O. Slane , B. M. Gaensler , T. Temim

Pulsar wind nebulae (PWNe) are clouds of the magnetized relativistic electron/positron plasma supplied from the central pulsar. However, the number of radio-emitting particles inside a PWN is larger than the expectation from the study of…

High Energy Astrophysical Phenomena · Physics 2024-05-08 Shuta J. Tanaka , Wataru Ishizaki

The model for pulsar wind nebulae (PWNe) as the result of the magnetohydrodynamic (MHD) downstream flow from a shocked, relativistic pulsar wind has been successful in reproducing many features of the nebulae observed close to the central…

High Energy Astrophysical Phenomena · Physics 2015-06-04 Xiaping Tang , Roger A. Chevalier

Starburst regions with multiple powerful winds of young massive stars and supernova remnants are favorable sites for high-energy cosmic ray acceleration. A supernova shock colliding with a fast wind from a compact cluster of young stars…

High Energy Astrophysical Phenomena · Physics 2015-09-15 A. M. Bykov , D. C. Ellison , P. E. Gladilin , S. M. Osipov

We discuss the observational properties of pulsar wind nebulae (PWNe) linking them to the injected (at the termination shock) electron spectral energy distribution and parameters of pulsar magnetospheres. In particular, we (1) present…

High Energy Astrophysical Phenomena · Physics 2018-01-24 Oleg Kargaltsev , Noel Klingler , Sarah Chastain , George G Pavlov

While supernova remnants (SNRs) have long been considered prime candidates as sources of cosmic rays, it is only recently that X-ray observations have identified several shell-type SNRs dominated by nonthermal emission, thus revealing…

Astrophysics · Physics 2007-05-23 Patrick Slane