scholarly journals Pulsar Wind Nebulae and Cosmic Rays: A Bedtime Story

2014 ◽  
Vol 256-257 ◽  
pp. 136-148 ◽  
Author(s):  
A. Weinstein
Keyword(s):  
Cosmic Rays ◽  
Pulsar Wind Nebulae ◽  
Pulsar Wind

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.

scholarly journals Balmer-Dominated Shocks: A Concise Review

2010 ◽  
Vol 27 (1) ◽  
pp. 23-44 ◽  
Author(s):  
Kevin Heng
Keyword(s):  
Cosmic Rays ◽  
Supernova Remnants ◽  
High Redshift ◽  
Ion Temperature ◽  
Pulsar Wind Nebulae ◽  
Collisionless Shocks ◽  
High Redshift Galaxies ◽  
Concise Review ◽  
Astrophysical Objects ◽  
Pulsar Wind

AbstractA concise and critical review of Balmer-dominated shocks (BDSs) is presented, summarizing the state of theory and observations, including models with/without shock precursors and their synergy with atomic physics. Observations of BDSs in supernova remnants are reviewed on an object-by-object basis. The relevance of BDSs towards understanding the acceleration of cosmic rays in shocks is emphasized. Probable and possible detections of BDSs in astrophysical objects other than supernova remnants, including pulsar wind nebulae and high-redshift galaxies, are described. The case for the continued future of studying BDSs in astrophysics is made, including their relevance towards understanding electron–ion temperature equilibration in collisionless shocks.

scholarly journals The contribution of Galactic TeV pulsar wind nebulae to Fermi-LAT diffuse emission

2021 ◽  
Author(s):  
Vittoria Vecchiotti ◽  
Giulia Pagliaroli ◽  
Francesco Villante
Keyword(s):  
Cosmic Rays ◽  
Energy Range ◽  
Spectral Index ◽  
Large Scale ◽  
Galactic Center ◽  
Galactic Plane ◽  
Diffuse Emission ◽  
Pulsar Wind Nebulae ◽  
Γ Ray ◽  
Pulsar Wind

Abstract The large-scale diffuse γ−ray flux observed by Fermi-LAT in the 1-100 GeV energy range, parameterized as ∝ E−Γ, has a spectral index Γ that depends on the distance from the Galactic center. This feature, if attributed to the diffuse emission produced by cosmic rays (CR) interactions with the interstellar gas, can be interpreted as the evidence of a progressive CR spectral hardening towards the Galactic center. This interpretation challenges the standard cosmic rays diffusion paradigm. We report on the implications of TeV Pulsar Wind Nebulae observed by the HESS Galactic Plane Survey in the 1-100 TeV energy range for the interpretation of Fermi-LAT data. We argue that a relevant fraction of this population cannot be resolved by Fermi-LAT in the GeV domain providing a relevant contribution to the large-scale diffuse emission, viz. the 30% of the total diffuse γ-ray emission in the inner Galaxy. This additional component naturally accounts for a large part of the spectral index variation observed by Fermi-LAT, weakening the evidence of CR spectral hardening in the inner Galaxy.

scholarly journals Introducing the HD+B model for pulsar wind nebulae: a hybrid hydrodynamics/radiative approach

2020 ◽  
Vol 494 (3) ◽  
pp. 4357-4370
Author(s):  
B Olmi ◽  
D F Torres
Keyword(s):  
Gamma Ray ◽  
High Energy ◽  
Theoretical Modelling ◽  
X Rays ◽  
Pulsar Wind Nebulae ◽  
New Approach ◽  
Energy Gamma ◽  
Radiative Model ◽  
Pulsar Wind

ABSTRACT Identification and characterization of a rapidly increasing number of pulsar wind nebulae is, and will continue to be, a challenge of high-energy gamma-ray astrophysics. Given that such systems constitute -by far- the most numerous expected population in the TeV regime, such characterization is important not only to learn about the sources per se from an individual and population perspective, but also to be able to connect them with observations at other frequencies, especially in radio and X-rays. Also, we need to remove the emission from nebulae in highly confused regions of the sky for revealing other underlying emitters. In this paper, we present a new approach for theoretical modelling of pulsar wind nebulae: a hybrid hydrodynamic-radiative model able to reproduce morphological features and spectra of the sources, with relatively limited numerical cost.

scholarly journals The H.E.S.S. Galactic Plane Survey

2009 ◽  
Vol 5 (H15) ◽  
pp. 808-808
Author(s):  
Emma de Oña-Wilhelmi
Keyword(s):  
Supernova Remnants ◽  
Binary Systems ◽  
Galactic Plane ◽  
Giant Molecular Clouds ◽  
Pulsar Wind Nebulae ◽  
Compact Binary ◽  
Pulsar Wind ◽  
Star Formation Regions ◽  
Galactic Sources ◽  
Gps Observations

AbstractThe H.E.S.S. Galactic Plane Survey (GPS) has revealed a large number of Galactic Sources, including Pulsar Wind Nebulae (PWN), Supernova Remnants (SNRs), giant molecular clouds, star formation regions and compact binary systems, as well as a number of unidentified objects, or dark sources, for which no obvious counterparts at other wavelengths have yet been found. We will review the latest results from the GPS observations and discuss the most interesting cases.

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