scholarly journals Pulsar Wind Nebulae with Bow Shocks: Non-thermal Radiation and Cosmic Ray Leptons

2017 ◽  
Vol 207 (1-4) ◽  
pp. 235-290 ◽  
Author(s):  
A. M. Bykov ◽  
E. Amato ◽  
A. E. Petrov ◽  
A. M. Krassilchtchikov ◽  
K. P. Levenfish
Keyword(s):  
Thermal Radiation ◽  
Cosmic Ray ◽  
Pulsar Wind Nebulae ◽  
Bow Shocks ◽  
Pulsar Wind

scholarly journals GeV Observations of the Extended Pulsar Wind Nebulae Constrain the Pulsar Interpretations of the Cosmic-Ray Positron Excess

2019 ◽  
Vol 878 (2) ◽  
pp. 104 ◽  
Author(s):  
Shao-Qiang Xi ◽  
Ruo-Yu Liu ◽  
Zhi-Qiu Huang ◽  
Kun Fang ◽  
Xiang-Yu Wang
Keyword(s):  
Cosmic Ray ◽  
Pulsar Wind Nebulae ◽  
Pulsar Wind

scholarly journals Pulsar wind nebulae created by fast-moving pulsars

2017 ◽  
Vol 83 (5) ◽  
Author(s):  
O. Kargaltsev ◽  
G. G. Pavlov ◽  
N. Klingler ◽  
B. Rangelov
Keyword(s):  
Hubble Space Telescope ◽  
Ambient Medium ◽  
Pulsar Wind Nebulae ◽  
The Past ◽  
Recent Developments ◽  
Pulsar Velocity ◽  
Bow Shocks ◽  
Observational Status ◽  
Pulsar Wind ◽  
Made In

We review multiwavelength properties of pulsar wind nebulae created by supersonically moving pulsars and the effects of pulsar motion on the pulsar wind nebulae morphologies and the ambient medium. Supersonic pulsar wind nebulae are characterized by bow-shaped shocks around the pulsar and/or cometary tails filled with the shocked pulsar wind. In the past several years significant advances in supersonic pulsar wind nebula studies have been made in deep observations with the Chandra and XMM-Newton X-ray observatories and the Hubble Space Telescope. In particular, these observations have revealed very diverse supersonic pulsar wind nebula morphologies in the pulsar vicinity, different spectral behaviours of long pulsar tails, the presence of puzzling outflows misaligned with the pulsar velocity and far-UV bow shocks. Here we review the current observational status focusing on recent developments and their implications.

scholarly journals Pulsar Wind Nebulae inside Supernova Remnants as Cosmic-Ray PeVatrons

2018 ◽  
Vol 478 (1) ◽  
pp. 926-931 ◽  
Author(s):  
Yutaka Ohira ◽  
Shota Kisaka ◽  
Ryo Yamazaki
Keyword(s):  
Supernova Remnants ◽  
Cosmic Ray ◽  
Pulsar Wind Nebulae ◽  
Pulsar Wind

scholarly journals PeV Emission of the Crab Nebula: Constraints on the Proton Content in Pulsar Wind and Implications

2021 ◽  
Vol 922 (2) ◽  
pp. 221
Author(s):  
Ruo-Yu Liu ◽  
Xiang-Yu Wang
Keyword(s):  
Energy Content ◽  
Crab Nebula ◽  
Cosmic Ray ◽  
Ultrahigh Energy ◽  
Pulsar Wind Nebulae ◽  
Air Shower ◽  
Pulsar Wind ◽  
The Crab Nebula ◽  
Pulsar Winds ◽  
Cosmic Ray Flux

Abstract Recently, two photons from the Crab Nebula with energy of approximately 1 PeV were detected by the Large High Altitude Air Shower Observatory (LHAASO), opening an ultrahigh-energy window for studying pulsar wind nebulae (PWNe). Remarkably, the LHAASO spectrum at the highest-energy end shows a possible hardening, which could indicate the presence of a new component. A two-component scenario with a main electron component and a secondary proton component has been proposed to explain the whole spectrum of the Crab Nebula, requiring a proton energy of 1046–1047 erg remaining in the present Crab Nebula. In this paper, we study the energy content of relativistic protons in pulsar winds using the LHAASO data of the Crab Nebula, considering the effect of diffusive escape of relativistic protons. Depending on the extent of the escape of relativistic protons, the total energy of protons lost in the pulsar wind could be 10–100 times larger than that remaining in the nebula presently. We find that the current LHAASO data allow up to (10–50)% of the spindown energy of pulsars being converted into relativistic protons. The escaping protons from PWNe could make a considerable contribution to the cosmic-ray flux of 10–100 PeV. We also discuss the leptonic scenario for the possible spectral hardening at PeV energies.

scholarly journals Constraining positron emission from pulsar populations with AMS-02 data

2021 ◽  
Vol 2021 (12) ◽  
pp. 014
Author(s):  
Luca Orusa ◽  
Silvia Manconi ◽  
Fiorenza Donato ◽  
Mattia Di Mauro
Keyword(s):  
Cosmic Ray ◽  
Physical Parameters ◽  
Pulsar Wind Nebulae ◽  
Positron Emission ◽  
The Galaxy ◽  
Emission Models ◽  
Pulsar Wind ◽  
Pulsar Populations ◽  
The Impact ◽  
Cosmic Ray Flux

Abstract The cosmic-ray flux of positrons is measured with high precision by the space-borne particle spectrometer AMS-02. The hypothesis that pulsar wind nebulae (PWNe) can significantly contribute to the excess of the positron (e+) cosmic-ray flux has been consolidated after the observation of a γ-ray emission at TeV energies of a few degree size around Geminga and Monogem PWNe. In this work we undertake massive simulations of galactic pulsars populations, adopting different distributions for their position in the Galaxy, intrinsic physical properties, pair emission models, in order to overcome the incompleteness of the ATNF catalog. We fit the e+ AMS-02 data together with a secondary component due to collisions of primary cosmic rays with the interstellar medium. We find that several mock galaxies have a pulsar population able to explain the observed e+ flux, typically by few, bright sources. We determine the physical parameters of the pulsars dominating the e+ flux, and assess the impact of different assumptions on radial distributions, spin-down properties, Galactic propagation scenarios and e+ emission time.

scholarly journals Connecting the ISM to TeV PWNe and PWN candidates

2019 ◽  
Vol 36 ◽  
Author(s):  
F. J. Voisin ◽  
G. P. Rowell ◽  
M. G. Burton ◽  
Y. Fukui ◽  
H. Sano ◽  
...  
Keyword(s):  
Cosmic Rays ◽  
Molecular Cloud ◽  
Molecular Clouds ◽  
Gamma Ray ◽  
Galactic Plane ◽  
Cosmic Ray ◽  
Molecular Gas ◽  
Pulsar Wind Nebulae ◽  
Density Estimates ◽  
Pulsar Wind

AbstractWe investigate the interstellar medium towards seven TeV gamma-ray sources thought to be pulsar wind nebulae using Mopra molecular line observations at 7 mm [CS(1–0), SiO(1–0, v = 0)], Nanten CO(1–0) data and the Southern Galactic Plane Survey/GASS Hisurvey. We have discovered several dense molecular clouds co-located to these TeV gamma-ray sources, which allows us to search for cosmic rays coming from progenitor SNRs or, potentially, from pulsar wind nebulae. We notably found SiO(1–0, v = 0) emission towards HESS J1809–193, highlighting possible interaction between the adjacent supernova remnant SNR G011.0–0.0 and the molecular cloud atd∼ 3.7 kpc. Using morphological features, and comparative studies of our column densities with those obtained from X-ray measurements, we claim a distanced∼ 8.6 − 9.7kpc for SNR G292.2–00.5,d∼ 3.5 − 5.6 kpc for PSR J1418–6058 andd∼ 1.5 kpc for the new SNR candidate found towards HESS J1303–631. From our mass and density estimates of selected molecular clouds, we discuss signatures of hadronic/leptonic components from pulsar wind nebulae and their progenitor SNRs. Interestingly, the molecular gas, which overlaps HESS J1026–582 atd∼ 5 kpc, may support a hadronic origin. We find however that this scenario requires an undetected cosmic-ray accelerator to be located atd< 10 pc from the molecular cloud. For HESS J1809–193, the cosmic rays which have escaped SNR G011.0–0.0 could contribute to the TeV gamma-ray emission. Finally, from the hypothesis that at most 20% the pulsar spin down power could be converted into CRs, we find that among the studied pulsar wind nebulae, only those from PSR J1809–1917 could potentially contribute to the TeV emission.

Hard X-ray emission from pulsar-wind nebulae

2016 ◽  
Vol 82 (5) ◽  
Author(s):  
Stephen P. Reynolds
Keyword(s):  
Energy Distribution ◽  
Gamma Rays ◽  
Crab Nebula ◽  
Cosmic Ray ◽  
Spectral Structure ◽  
Particle Spectrum ◽  
Pulsar Wind Nebulae ◽  
Pulsar Wind ◽  
Tev Gamma Rays ◽  
The Crab Nebula

Pulsar-wind nebulae emit an extremely broad spectrum of continuum radiation, from low radio frequencies to TeV gamma rays. The part of the spectral energy distribution (SED) from radio through MeV gamma rays is due to synchrotron emission from a distribution of relativistic electrons (or pairs) which can be described by one or more power laws. This spectrum exhibits that particle energy distribution, responsible also for the higher-energy (GeV–TeV) part of the SED, due to inverse-Compton upscattering of one of three photon fields: the synchrotron spectrum, the cosmic microwave background, or ambient optical/infrared photons. However, in a few sources, primary hadrons may produce GeV–TeV gamma rays through the decay of neutral pions produced in inelastic cosmic-ray collisions with thermal gas. The higher-energy end of the particle spectrum, producing synchrotron photons above approximately 10 keV, holds clues to the particle acceleration process. However, its detailed study requires imaging spectroscopy in this energy range, not available until the NuSTAR mission beginning in 2012, which performs true imaging between 3 and 78 keV with ${\sim}1^{\prime }$ angular resolution. I review NuSTAR observations of the first three pulsar-wind nebulae (PWNe) to be examined in this way: the Crab Nebula, G21.5–0.9 and MSH 15–52. All three show spectral structure not previously known: spectral steepening in certain locations and overall source shrinkage with increasing photon energy. The Crab Nebula has different shrinkage rates along the torus and along the northwest counter-jet. The latter rate is similar to that for both the other sources (FWHM $\propto E^{m}$ with $m\sim -0.2$). I discuss implications of these results for models of particle transport in PWNe.

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