scholarly journals Energetic Particles in a Flare Loop: Spectra and Radiation Signatures

1990 ◽  
Vol 142 ◽  
pp. 421-427
Author(s):  
P. A. Bespalov ◽  
V. V. Zaitsev ◽  
A. V. Stepanov
Keyword(s):  
Gamma Ray ◽  
High Energy ◽  
Propagation Model ◽  
Source Spectrum ◽  
High Energy Particle ◽  
Particle Interactions ◽  
Flare Loop ◽  
Energetic Ions ◽  
Particle Spectra ◽  
One Step

It has been shown that high energy particle spectra, particle dynamics, and radiation in a flare loop are determined by wave-particle interactions. The electron-whistler interaction occurs under conditions of strong pitch angle diffusion that makes the particle distribution function isotropic. The flare loop electrons retain information about the particle source spectrum. The interaction of energetic ions with Alfven waves is characterized by strong, moderate, and weak diffusion. The time delays in hard X-ray and gamma-ray emission during one-step acceleration processes might be understood in terms of a trap-plus-turbulent propagation model. The density of precipitating particles is less than or equal to the trapping one. Radiation signatures of flare loop electrons are discussed.

Multiplicities in a QCD-motivated description of very high energy particle interactions

1986 ◽  
Vol 166 (2) ◽  
pp. 219-222 ◽  
Author(s):  
T.K. Gaisser ◽  
F. Halzen ◽  
A.D. Martin ◽  
C.J. Maxwell
Keyword(s):  
High Energy ◽  
High Energy Particle ◽  
Particle Interactions ◽  
Energy Particle ◽  
Very High Energy ◽  
Very High

scholarly journals The supernova remnant W49B as seen with H.E.S.S. and Fermi-LAT

2018 ◽  
Vol 612 ◽  
pp. A5 ◽  
Author(s):  
◽  
H. Abdalla ◽  
A. Abramowski ◽  
F. Aharonian ◽  
F. Ait Benkhali ◽  
...  
Keyword(s):  
Supernova Remnant ◽  
Gamma Ray ◽  
Surrounding Medium ◽  
High Energy ◽  
Galactic Cosmic Rays ◽  
Source Spectrum ◽  
Cherenkov Telescopes ◽  
High Energies ◽  
Very High ◽  
Subsequent Emission

The supernova remnant (SNR) W49B originated from a core-collapse supernova that occurred between one and four thousand years ago, and subsequently evolved into a mixed-morphology remnant, which is interacting with molecular clouds (MC). Gamma-ray observations of SNR-MC associations are a powerful tool to constrain the origin of Galactic cosmic rays, as they can probe the acceleration of hadrons through their interaction with the surrounding medium and subsequent emission of non-thermal photons. We report the detection of a γ-ray source coincident with W49B at very high energies (VHE; E > 100 GeV) with the H.E.S.S. Cherenkov telescopes together with a study of the source with five years of Fermi-LAT high-energy γ-ray (0.06–300 GeV) data. The smoothly connected, combined source spectrum, measured from 60 MeV to multi-TeV energies, shows two significant spectral breaks at 304 ± 20 MeV and 8.4−2.5+2.2 GeV; the latter is constrained by the joint fit from the two instruments. The detected spectral features are similar to those observed in several other SNR-MC associations and are found to be indicative of γ-ray emission produced through neutral-pion decay.

Astrophysics and Particle Physics in Space with the Alpha Magnetic Spectrometer

2003 ◽  
Vol 18 (28) ◽  
pp. 1951-1966 ◽  
Author(s):  
Giovanni Lamanna
Keyword(s):  
Particle Physics ◽  
Gamma Ray ◽  
Space Shuttle ◽  
Space Station ◽  
Cosmic Ray ◽  
High Energy ◽  
Magnetic Spectrometer ◽  
High Energy Particle ◽  
Physics Experiment ◽  
Alpha Magnetic Spectrometer

The Alpha Magnetic Spectrometer (AMS) is a high energy particle physics experiment in space scheduled to be installed on the International Space Station (ISS) by 2006 for a three-year mission. After a precursor flight of a prototype detector on board of the NASA Space Shuttle in June 1998, the construction of the detector in its final configuration is started and it will be completed by 2004. The purpose of this experiment is to provide a high statistics measurement of charged particles and nuclei in rigidity range 0.5 GV to few TV and to explore the high-energy (> 1 GeV ) gamma-ray sky. In this paper we describe the detector layout and present an overview of the main scientific goals both in the domain of astrophysics: cosmic-ray origin, age and propagation and the exploration of the most energetic gamma-ray sources; and in the domain of astroparticle: the anti-matter and the dark matter searches.

scholarly journals POLARIZED STRUCTURE FUNCTIONS AND SPIN PHYSICS

2002 ◽  
Vol 17 (23) ◽  
pp. 3220-3238
Author(s):  
UTA STÖSSLEIN
Keyword(s):  
Parton Distribution ◽  
Spin Structure ◽  
High Energy ◽  
Structure Functions ◽  
Distribution Functions ◽  
High Energy Particle ◽  
Particle Interactions ◽  
Parton Distribution Functions ◽  
Spin Physics ◽  
Further Development

Recent progress in the field of spin physics of high energy particle interactions is reviewed with particular emphasis on the spin structure functions as measured in polarized deep inelastic lepton-nucleon scattering (DIS). New measurements are presented to obtain more direct information on the composition of the nucleon angular momentum, with results from semi-inclusive DIS accessing flavour-separated parton distribution functions (PDF) and with first data from hard exclusive reactions which may be interpreted in terms of recently developed generalizations of parton distribution functions (GPD). Finally, experimental prospects are outlined which will lead to a further development of the virtues of QCD phenomenology of the spin structure of the nucleon.

scholarly journals Magnetic fractures or reconnection of type II

2010 ◽  
Vol 6 (S274) ◽  
pp. 56-61
Author(s):  
Gerhard Haerendel
Keyword(s):  
Particle Production ◽  
Gamma Ray ◽  
Magnetic Energy ◽  
High Energy ◽  
Compact Objects ◽  
High Energy Particle ◽  
Shear Stresses ◽  
Low Density ◽  
Field Lines ◽  
Auroral Arcs

AbstractThe importance of reconnection in astrophysics has been widely recognized. It is instrumental in storing and releasing magnetic energy, the latter often in a dramatic fashion. A closely related process, playing in very low beta plasmas, is much less known. It is behind the acceleration of auroral particles in the low-density environment several 1000 km above the Earth. It involves the appearance of field-parallel voltages in presence of intense field-aligned currents. The underlying physical process is the release of magnetic shear stresses and conversion of the liberated magnetic energy into kinetic energy of the particles creating auroral arcs. In this process, field lines disconnect from the field anchored in the ionosphere and reconnect to other field lines. Because of the stiffness of the magnetic field, the process resembles mechanical fractures. It is typically active in the low-density magnetosphere of planets. However, it can also lead to significant energy conversion with high-energy particle production and subsequent gamma ray emissions in stellar magnetic fields, in particular of compact objects.

scholarly journals Hydrophone characterization for the KM3NeT experiment

2019 ◽  
Vol 216 ◽  
pp. 02007
Author(s):  
Rasa Muller ◽  
Sander von Benda-Beckmann ◽  
Ed Doppenberg ◽  
Robert Lahmann ◽  
Ernst-Jan Buis
Keyword(s):  
Mediterranean Sea ◽  
High Energy ◽  
High Energy Particle ◽  
Particle Interactions ◽  
Energy Particle ◽  
Radiation Induced ◽  
The Mediterranean ◽  
Under Construction ◽  
Cosmic Origin ◽  
Do So

With the KM3NeT experiment, which is presently under construction in the Mediterranean Sea, a new neutrino telescope will be installed to study both the neutrino properties as well as the cosmic origin of these particles. To do so, about 6000 optical modules will be installed in the abyss of the Mediterranean Sea to observe the Cherenkov radiation induced by high energy particle interactions in the deep sea. As each module of the KM3NeT telescope includes a piezo hydrophone, KM3NeT will also provide a unique matrix of underwater hydrophones. Results from the measurements show a well understood response of continuous signals, such as tones. In contrast, the response to transients signals exhibit a complex behavior with ringing and echo’s. Amplitude calibration measurements show a frequency dependent response which can be corrected for. Finally a system noise floor has been determined which amounts to 45 dB Re μPa2/Hz at 30 kHz.

HIGH-ENERGY PARTICLE INTERACTIONS IN THE INNER JET OF THE RADIO GALAXY M87

2010 ◽  
Vol 19 (06) ◽  
pp. 957-963
Author(s):  
CHLOÉ GUENNOU ◽  
GUSTAVO E. ROMERO ◽  
GABRIELA S. VILA
Keyword(s):  
Gamma Ray ◽  
Radio Galaxy ◽  
Spectral Energy Distribution ◽  
High Energy ◽  
Spectral Energy ◽  
High Energy Particle ◽  
Zone Model ◽  
Rapid Variability ◽  
Central Engine ◽  
Energy Gamma

Recent observations with the High Energy Stereoscopic System (HESS) have revealed strong and variable high energy gamma-ray emission from the radio galaxy M87. The origin of such emission is uncertain, but the rapid variability indicates that it should be produced close to the central engine of the source. In this work, a lepto-hadronic one-zone model is applied to the available multiwavelength data of M87. The different energy losses for both primary and secondary particles are calculated. Then, the different contributions to the spectral energy distribution through interactions with matter, radiation and magnetic fields are obtained, in good accordance with the observations.

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