Interplanetary and solar electrons of energy 3–12 MeV

1968 ◽  
Vol 46 (10) ◽  
pp. S761-S765 ◽  
Author(s):  
T. L. Cline ◽  
F. B. McDonald
Keyword(s):  
Interplanetary Space ◽  
Solar Physics ◽  
Strong Dependence ◽  
Cosmic Ray ◽  
High Energy ◽  
Solar Modulation ◽  
Relativistic Electrons ◽  
Time Histories ◽  
Electron Intensity ◽  
Time Variations

This paper reviews two topics related to the low-energy relativistic electrons detected in interplanetary space with the satellites IMP-I, IMP-II, and IMP-III:1. The first observations of 3–12-MeV solar-flare electrons in interplanetary space are presented. The solar electrons detected have kinetic energies nearly two orders of magnitude higher than any previously studied; thus, although flare events with a detectable flux of such particles occur relatively rarely, their study provides a new parameter in solar physics. The 7 July and 14 September 1966 events are outlined in detail, having the greatest relativistic electron to medium-energy proton ratios of the events detected before 1967. These events contrast with the 28 August 1966 event, which was intense in nucleons but contained no detectable component of relativistic electrons. The electron time histories are shown to have delayed onsets, and to be similar in form to those of high-energy protons, and the energy spectra and other features are described.2. Progress in the study of the solar modulation of interplanetary 3–12-MeV electrons is reviewed. Characteristics of the electron-intensity time variations during parts of 1963–67 are outlined; they are shown to be consistent with the hypothesis of the primary cosmic-ray nature of these particles and with a strong dependence on the local field conditions.

scholarly journals Quasielastic Lepton Scattering off Two-Component Dark Matter in Hypercolor Model

Symmetry ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 708 ◽  
Author(s):  
Vitaly Beylin ◽  
Maxim Bezuglov ◽  
Vladimir Kuksa ◽  
Egor Tretiakov
Keyword(s):  
Dark Matter ◽  
Total Cross Section ◽  
Cross Section ◽  
Strong Dependence ◽  
Cosmic Ray ◽  
High Energy ◽  
Dominant Contribution ◽  
Quasielastic Scattering ◽  
Two Component ◽  
The Cross

The interaction of high-energy leptons with components of Dark Matter in a hypercolor model is considered. The possibility of detection, using IceCube secondary neutrinos produced by quasielastic scattering of cosmic ray electrons off hidden mass particles, is investigated. The dominant contribution to the cross section results from diagrams with scalar exchanges. A strong dependence of the total cross section on the Dark Matter components mass is also found.

scholarly journals Recent Results from the CANGAROO Project

1996 ◽  
Vol 160 ◽  
pp. 363-364
Author(s):  
S.A. Dazeley ◽  
P.G. Edwards ◽  
J.R. Patterson ◽  
G.P. Rowell ◽  
M. Sinnott ◽  
...  
Keyword(s):  
Gamma Rays ◽  
South Australia ◽  
Cosmic Ray ◽  
High Energy ◽  
Relativistic Electrons ◽  
Large Numbers ◽  
Inverse Compton ◽  
Very High Energy ◽  
Large Telescopes ◽  
Very High

TheCollaboration ofAustralia andNippon for aGAmmaRayObservatory in theOutback operates two large telescopes at Woomera (South Australia), which detect the Čerenkov light images produced in the atmosphere by electronpositron cascades initiated by very high energy (~1 TeV or 1012eV) gamma rays. These gamma rays arise from a different mechanism than at EGRET energies: inverse Compton (IC) emission from relativistic electrons.The spoke-like images are recorded by a multi-pixel camera which facilitates the rejection of the large numbers of oblique and ragged cosmic ray images. A field of view ~3.5° is required. The Australian team operates a triple 4 m diameter mirror telescope, BIGRAT, with a 37 photomultiplier tube camera and energy threshold 600 GeV. The Japanese operate a single, highly accurate 3.8 m diameter f/1 telescope and high resolution 256 photomultipler tube camera. In 1998 a new 7 m telescope is planned for Woomera with a design threshold ~;200GeV.

scholarly journals High Energy Phenomena in the Sun

1981 ◽  
Vol 94 ◽  
pp. 367-372
Author(s):  
Claudio Chiuderi
Keyword(s):  
Solar Flares ◽  
Solar Surface ◽  
Solar Physics ◽  
Total Duration ◽  
Cosmic Ray ◽  
Total Surface Area ◽  
High Energy ◽  
Energy Scale ◽  
Image Position ◽  
Large Flare

High energy phenomena in the solar physics context, simply means solar flares. To be sure, the energies attained during flares are certainly not very impressive on a cosmic-ray scale. The most energetic particles belong the GeV range, the highest temperatures are of the order of 107 K, γ-ray emission is occasional and the total energy emitted remains below 1033 ergs for all the flares so far observed. Apart from an absolute energy scale, flares are also energetically irrelevant on a solar scale. In fact in a large flare a few units in 1032 ergs are emitted, with a total duration of about one hour and a total surface area involved of a few units in 10−4 of the solar surface. Recalling the values of the luminosity, L⊙ ≃ 4 × 1033 erg s−1 and the solar flux F⊙6.3 × 1010 erg cm−2s−1, we see that

Time variations of directional cosmic ray intensity at low latitudes - III. Interpretation of solar daily variation and changes of east-west asymmetry

1961 ◽  
Vol 263 (1312) ◽  
pp. 127-135 ◽  
Keyword(s):  
Energy Spectrum ◽  
Interplanetary Space ◽  
Daily Variation ◽  
Cosmic Ray ◽  
Local Source ◽  
Cosmic Ray Intensity ◽  
The Earth ◽  
Low Latitudes ◽  
Time Variations ◽  
East West

The daily variation of cosmic ray intensity at low latitudes can under certain conditions be associated with an anisotropy of primary radiation. During 1957-8, this anisotropy had an energy spectrum of variation of the form aϵ -0.8±0.3 and corresponded to a source situated at an angle of 112 ± 10° to the left of the earth-sun line. The daily variation which can be associated with a local source situated along the earth-sun line has an energy spectrum of variation of the form aϵ 0 . Increases in east-west asymmetry and the associated daily variation for east and west directions can be explained by the acceleration of cosmic ray particles crossing beams of solar plasma in the neighbourhood of the earth. For beams of width 5 x 10 12 cm with a frozen magnetic field of the order of 10 -4 G, a radial velocity of about 1.5 x 108 cm/s is required. The process is possible only if the ejection of beams takes place in rarefied regions of inter­ planetary space which extend radially over active solar regions. An explanation of Forbush, type decreases observed at great distances from the earth requires similar limitation on the plasma density and conductivity of regions of interplanetary space. The decrease of east-west asymmetry associated with world-wide decreases of intensity and with SC magnetic storms is consistent with a screening of the low-energy cosmic ray particles due to magnetic fields in plasma clouds.

scholarly journals High energy cosmic photons and neutrinos

1965 ◽  
Vol 23 ◽  
pp. 195-225
Author(s):  
R. J. Gould ◽  
G. R. Burbidge
Keyword(s):  
Supernova Remnants ◽  
Crab Nebula ◽  
Meson Production ◽  
Cosmic Ray ◽  
High Energy ◽  
Relativistic Electrons ◽  
X Ray ◽  
Hard Radiation ◽  
The Galaxy ◽  
The Crab Nebula

This review concentrates primarily on the problem of interpreting the recent X-ray and γ-ray observations of celestial sources. The expected fluxes of hard radiation from various processes are estimated (when possible) and are compared with the observations. We compute the synchrotron, bremsstrahlung, and (inverse) Compton spectra originating from relativistic electrons produced (via meson production) in the galaxy and intergalactic medium by cosmic ray nuclear collisions; the spectra from π°-decay are also computed. Neutron stars, stellar coronae, and supernova remnants are reviewed as possible X-ray sources. Special consideration is given to the processes in the Crab Nebula. Extragalactic objects as discrete sources of energetic photons are considered on the basis of energy requirements; special emphasis is given to the strong radio sources and the possibility of the emission of hard radiation during their formation. The problem of the detection of cosmic neutrinos is reviewed.As yet, no definite process can be identified with any of the observed fluxes of hard radiation, although a number of relevant conclusions can be drawn on the basis of the available preliminary observational results. In particular, some cosmogonical theories can be tested.

Some Astrophysical Implications of Recent Measurements on the Intensity of Cosmic-Ray Electrons

1968 ◽  
Vol 1 (3) ◽  
pp. 112-113 ◽  
Author(s):  
W.R. Webber
Keyword(s):  
Electron Spectrum ◽  
Cosmic Ray ◽  
Solar Modulation ◽  
List Type ◽  
Secondary Electrons ◽  
The Earth ◽  
Thermal Radio Emission ◽  
The Galaxy ◽  
Electron Intensity ◽  
Spiral Arm

We have extended our recent measurements on the extraterrestrial cosmic ray electron spectrum, this spectrum now being determined over the energy range from ~15 MeV to 6 GeV. The extraterrestrial electron intensity between 15 MeV and 200 MeV can be determined unambiguously by studying the diurnal variation of these particles. We have also measured the effects of the 11-year solar modulation on the electrons, thus enabling the electron spectrum observed near the Earth to be extrapolated to the local region of the spiral arm. It is the purpose of this paper to relate these measurements to: (i) calculations of ‘secondary’ electrons produced by cosmic ray nuclei moving in the Galaxy; and(ii) the observations of non-thermal radio emission from disk components of the Galaxy.

scholarly journals High Energy Radiation Generated at Boundary Shear Layers of Relativistic Jets

2002 ◽  
Vol 19 (1) ◽  
pp. 22-25 ◽  
Author(s):  
Ł. Stawarz ◽  
M. Ostrowski
Keyword(s):  
Electron Distribution ◽  
Low Frequency ◽  
Cosmic Ray ◽  
High Energy ◽  
Particle Energy ◽  
Relativistic Electrons ◽  
Microwave Background ◽  
Boundary Shear ◽  
Inverse Compton ◽  
Energy Gains

AbstractA simple model of cosmic ray electron acceleration at the jet boundary yields a power law particle energy distribution of ultra-relativistic electrons with an energy cut-off growing with time, and, finally, a growing particle bump at the energy where energy gains equal radiation losses. For such electron distribution, in tens-of-kpc scale jets, we derived the observed time-varying spectra of synchrotron and inverse Compton radiation, including Comptonisation of synchrotron and cosmic microwave background photons. Slowly varying spectral index along the jet in the ‘low frequency’ spectral range is a natural consequence of boundary layer acceleration. Variations of the high energy bump of the electron distribution can give rise to anomalous behaviour in the X-ray band in comparison to the lower frequencies.

Satellite measurements of the low-energy cosmic-ray Li, Be, B, C, N, O, F nuclei and their implications

1968 ◽  
Vol 46 (10) ◽  
pp. S548-S552 ◽  
Author(s):  
C. Y. Fan ◽  
George Gloeckler ◽  
J. A. Simpson
Keyword(s):  
Energy Spectrum ◽  
Interplanetary Space ◽  
Cosmic Ray ◽  
Low Energy ◽  
Solar Modulation ◽  
Chemical Abundance ◽  
Satellite Measurements ◽  
Differential Energy Spectrum

The differential energy spectrum and chemical abundance of individual elements from lithium to fluorine have been measured near minimum solar modulation (June 1965 to March 1966) in interplanetary space on the IMP-III satellite. The spectra for Li, Be, and B are found to increase with decreasing energy below ~60 MeV/nucleon. The consequences of these results on the propagation and lifetimes of cosmic-ray particles are discussed.

Diffusion of high-energy solar particles through interplanetary space

1968 ◽  
Vol 46 (10) ◽  
pp. S772-S775 ◽  
Author(s):  
I. Kondo ◽  
K. Fujimoto ◽  
K. Nagashima ◽  
H. Oda
Keyword(s):  
Magnetic Field ◽  
Lower Energy ◽  
Interplanetary Space ◽  
Cosmic Ray ◽  
High Energy ◽  
Maximum Density ◽  
Satellite Observations ◽  
Number Density ◽  
The Earth ◽  
Relativistic Particles

The effects of the interplanetary magnetic field on the propagation of solar cosmic-ray particles are studied. The presence of the quasi-stable magnetic field of garden-hose type found by satellite observations suggests that the movement of the particles along these lines of force is much easier than that perpendicular to them. The diffusion equation of the particles through such a medium is solved, and the number density of particles at the earth is computed for several values of parameters. The results of the computation concerning the dependence of the time of maximum density on the position of the source relative to the sun–earth line are compared with those obtained from observations. It is found that the diffusion coefficient perpendicular to the line of force is 1/10 to 1/20 of that parallel to the line for relativistic particles, while the ratio is 1/50 to 1/100 for lower-energy particles.

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