scholarly journals A Satellite Experiment to Measure the Intensity and the Energy Spectrum of Gamma Rays from Solar Flares in the Range 50–500 MeV

1971 ◽  
Vol 41 ◽  
pp. 44-44
Author(s):  
G. F. Bignami ◽  
C. J. Bland ◽  
O. Citterio ◽  
A. J. Dean ◽  
P. Inzani
Keyword(s):  
Energy Spectrum ◽  
Solar Flare ◽  
Gamma Rays ◽  
Solar Flares ◽  
Gamma Ray ◽  
High Energy ◽  
Measurement Capability ◽  
Satellite Experiment

A high energy solar gamma-ray telescope incorporating a lenticular Čerenkov for directional measurement and an energy calorimeter is described. The instrument is included in the payload of the TD-1 ESRO spacecraft to be launched into a sun-pointing orbit during spring 1972. The results of laboratory and accelerator tests are presented and the sensitivity and measurement capability to solar flare gamma rays is discussed.

High-Energy Solar Gamma-Ray Observations

1998 ◽  
Vol 11 (2) ◽  
pp. 755-758
Author(s):  
M. Yoshimori ◽  
N. Saita ◽  
A. Shiozawa
Keyword(s):  
Particle Acceleration ◽  
Gamma Rays ◽  
Solar Flares ◽  
Gamma Ray ◽  
Solar Maximum ◽  
High Energy ◽  
The Sun ◽  
Long Duration ◽  
New Findings ◽  
Gamma Ray Emission

In the last solar maximum, gamma-rays associated with solar flares were observed with GRANAT, GAMMA-1, CGRO and YOHKOH. The gamma-ray energies ranged from 100 keV to a few GeV. We obtained several new findings of gamma-ray emission on the Sun: (1) Gamma-ray production in the corona, (2) GeV gamma-ray production in very long duration flares, (3) Electron-rich flares, (4) Gamma-ray lines and solar atmospheric abundances and (5) Possible location of gamma-ray emission. We present the observations of these new findings and discuss high energy phenomena relating to particle acceleration and gamma-ray production during solar flares.

scholarly journals Gamma-Ray Precursors of Solar Flares

1994 ◽  
Vol 142 ◽  
pp. 645-648
Author(s):  
E. Rieger
Keyword(s):  
Spatial Resolution ◽  
Gamma Rays ◽  
Solar Flares ◽  
Gamma Ray ◽  
High Energy ◽  
X Rays ◽  
High Energy Gamma ◽  
Gamma Ray Spectrometer ◽  
Energy Gamma ◽  
Negligible Contribution

AbstractBursts have been observed by the gamma-ray spectrometer on SMM at medium- and high-energy gamma-rays that precede the flare maximum. The negligible contribution of nuclear lines in the spectra of these events and their impulsive appearance suggests that they are hard-electron-dominated events superposed on the flares. Spatial resolution at gamma-ray energies will be necessary to decide whether this kind of bursts is cospatial with the flares or whether they occur in the flares’ vicinity.Subject headings: Sun: flares — Sun: X-rays, gamma rays

scholarly journals High Energy Gamma Rays from Pulsars

1981 ◽  
Vol 95 ◽  
pp. 251-254
Author(s):  
P. N. Bhat ◽  
S. K. Gupta ◽  
P.V. Ramana Murthy ◽  
B. V. Sreekantan ◽  
S. C. Tonwar ◽  
...  
Keyword(s):  
Energy Spectrum ◽  
Gamma Rays ◽  
Gamma Ray ◽  
High Energy ◽  
High Energy Gamma ◽  
High Energies ◽  
Energy Gamma ◽  
Gamma Ray Emission ◽  
Atmospheric Čerenkov Technique

We present here the results from observations of pulsed gamma ray emission from the Crab and Vela pulsars for energies above 100 GeV using the atmospheric Cerenkov technique. The results suggest a very steep energy spectrum for gamma rays emitted from pulsars at high energies. Our observations over the last 4 years suggest also that the flux is highly variable with time.

scholarly journals Solar Gamma Rays and their Correlation with Space and Ground-Based Observations

1968 ◽  
Vol 1 ◽  
pp. 544-546
Author(s):  
G.G. Fazio
Keyword(s):  
Solar Cycle ◽  
Solar Flare ◽  
Gamma Rays ◽  
Solar Flares ◽  
Radiation Spectrum ◽  
High Energy ◽  
Electromagnetic Spectrum ◽  
Major Flare ◽  
Integral Energy ◽  
Flare Model

Thus far, only two experiments have detected solar γ-radiation with energy significantly greater than 200 keV. In both events the γ-ray emission occurred during a solar flare. The first observation was in 1958 by Peterson and Winckler (1959), who recorded a burst of radiation that occurred in less than 18 sec from a class-2 solar flare. The radiation spectrum peaked in the 200- to 500-keV region. Recently, Cline et al. (1967) recorded in the OGO-3 satellite three rapid γ-ray bursts in the 80-keV to 1-MeV energy range and measured the integral energy spectrum. The measurements were made on July 7, 1966, during the first high-intensity flare (importance 3) of the new solar cycle. Many attempts have been made to measure higher energy γ-radiation from the quiet Sun and from solar flares, but no flux has been detected; this is primarily due to the fact that no high-energy γ-ray detectors have viewed a major solar flare during the maximum of the optical or microwave burst. However, theoretical estimates of the flux of solar γ-rays, based on a simple flare model, indicate a readily detectable flux from a major flare even to photon energies of 100 MeV. It is therefore important that experiments be performed during the coming maximum of the solar cycle to investigate this region of the electromagnetic spectrum.

scholarly journals Solar Flares: High-Energy Radiation and Particles

1989 ◽  
Vol 104 (1) ◽  
pp. 323-345 ◽  
Author(s):  
Erich Rieger
Keyword(s):  
Particle Acceleration ◽  
Gamma Rays ◽  
Solar Flares ◽  
Gamma Ray ◽  
Review Paper ◽  
Interplanetary Space ◽  
High Energy ◽  
Solar Disc ◽  
High Energy Radiation ◽  
Energy Radiation

AbstractDue to the Sun's proximity flares can be investigated in the gamma-ray regime and flare generated particles can be measured in space and related to particular events. In this review paper we focus on the problem of particle acceleration by using as observational ingredients: the fluxes and spectra of particles inferred from gamma-ray measurements and observed in interplanetary space, the temporal characteristics of flares at high-energy X- and gamma-rays and the distribution of gamma-ray flares over the solar disc.

scholarly journals THE APPLICATION OF THE BrilLanCe SERIES SCINTILLATION DETECTOR IN THE SPECTROMETER OF NEUTRAL PARTICLES FOR THE SATELLITE EXPERIMENT ZINA-NT

2012 ◽  
Vol 12 ◽  
pp. 28-36
Author(s):  
IRENE V. ARKHANGELSKAJA ◽  
ANDREY I. ARKHANGELSKY ◽  
ALEXEY.G BATISCHEV ◽  
ARKADY M. GALPER ◽  
NATALYA V. KONDRATYEVA ◽  
...  
Keyword(s):  
Gamma Rays ◽  
Solar Flares ◽  
Gamma Ray ◽  
Light Output ◽  
Gamma Ray Bursts ◽  
X Ray ◽  
Neutral Particles ◽  
Satellite Experiment ◽  
Excellent Energy Resolution ◽  
Radiation Conditions

Spectrometric detector complex ZINA-NT is intended to study a radiation conditions onboard satellite and characteristics of hard X-ray and gamma-ray fluxes from GRB, solar flares and to detect other non-stationary fluxes of cosmic gamma-rays. The advantages for using of this new detector for modification of present neutral particles detector on the base of CsI(Tl) are discussed. Scintillation detectors based on BrilLanCe series crystal have got very small lighting time, an excellent energy resolution and light output, more intensive than devices based on CsI(Tl). Using of BrilLanCe series crystal instead of CsI(Tl) ones allows to detect terrestrial gamma flashes (TGF), gamma ray bursts (GRB) and solar flares with smaller time durations and intensities. Moreover, the counts rate linearity region of BrilLanCe detectors is extended up to 106 s-1 and it allows to observe a very intensive events. So, the using of such type of detector permits us the possibility to separate gamma-quanta and neutrons on the timescales less than 50 microseconds.

scholarly journals Solar Hard X-Ray and Gamma-Ray Observations from GRANAT

1994 ◽  
Vol 142 ◽  
pp. 611-621
Author(s):  
N. Vilmer
Keyword(s):  
Gamma Rays ◽  
Solar Flares ◽  
Gamma Ray ◽  
Ground Level ◽  
High Energy ◽  
Angle Distribution ◽  
X Rays ◽  
X Ray ◽  
Electrons And Ions ◽  
Solar Bursts

AbstractHard X-rays and gamma-rays are the most direct signature of the energetic electrons and ions which are accelerated during solar flares. Since the beginning of 1990 the PHEBUS instrument and the SIGMA anticoincidence shield aboard GRANAT have provided hard X-ray and gamma-ray observations of solar bursts in the energy range 0.075-124 and 0.200-15 MeV, respectively. After a brief description of the experiments, we present some results obtained on solar bursts recorded in 1990 and 1991 June. Special emphasis is given to the results related with particle acceleration during solar flares.The first part of the review is devoted to the constraints obtained on the electron acceleration timescale through the analysis of the temporal characteristics of the bursts. Combined studies of hard X-ray and gamma-ray emissions from PHEBUS and radio emissions from the Nançay Multifrequency Radioheliograph are used to infer constraints on the coronal magnetic topology involved in flares. The characteristics (location, spectrum) of the radio-emitting sources are found to vary within a flare from one hard X-ray peak to the other. Hard X-ray and gamma-ray burst onsets and rapid increases of the > 10 MeV emission are coincident with changes in the associated radio emission pattern. These results will be discussed in the context of the flare energy release.The second part of the paper concerns the heliocentric angle distribution of > 10 MeV events and presents more detailed observations of some of the largest flares in the gamma-ray line and the high-energy domains produced by ultrarelativistic electrons and > 100 MeV nucleon−1 ions. The PHEBUS observations of the gamma-ray line flare of 11 June 1991 have been used to deduce the hardness of the accelerated ion spectrum. The link between the main part of the flare and the late long-lasting >50 MeV emission detected by EGRET/COMPTON is discussed. Finally some observations of the large 1990 May 24 flare which produced a large neutron event at ground level are presented.Subject headings: acceleration of particles — Sun: flares — Sun: radio radiation — Sun: X-rays, gamma rays

A satellite experiment to measure the intensity and energy spectrum of gamma rays from solar flares in the range 50–500 MeV

1972 ◽  
Vol 103 (1) ◽  
pp. 149-156 ◽  
Author(s):  
G.F. Bignami ◽  
C.J. Bland ◽  
O. Citterio ◽  
A.J. Dean ◽  
P. Inzani
Keyword(s):  
Energy Spectrum ◽  
Gamma Rays ◽  
Solar Flares ◽  
Satellite Experiment

Solar Flare Energetic Neutral Emission Measurements in the Project Coronas-I

1994 ◽  
Vol 144 ◽  
pp. 635-639
Author(s):  
J. Baláž ◽  
A. V. Dmitriev ◽  
M. A. Kovalevskaya ◽  
K. Kudela ◽  
S. N. Kuznetsov ◽  
...  
Keyword(s):  
Solar Flare ◽  
Energy Range ◽  
Gamma Rays ◽  
Pulse Shape ◽  
Gamma Ray ◽  
Pulse Shape Discrimination ◽  
Shape Discrimination ◽  
Solar Neutron ◽  
Low Altitude

AbstractThe experiment SONG (SOlar Neutron and Gamma rays) for the low altitude satellite CORONAS-I is described. The instrument is capable to provide gamma-ray line and continuum detection in the energy range 0.1 – 100 MeV as well as detection of neutrons with energies above 30 MeV. As a by-product, the electrons in the range 11 – 108 MeV will be measured too. The pulse shape discrimination technique (PSD) is used.

scholarly journals Modeling Gamma-Ray SEDs and Angular Extensions of Extreme TeV Blazars from Intergalactic Proton-Initiated Cascades in Contemporary Astrophysical EGMF Models

Universe ◽  
2021 ◽  
Vol 7 (7) ◽  
pp. 220
Author(s):  
Emil Khalikov
Keyword(s):  
Gamma Rays ◽  
Large Scale ◽  
Gamma Ray ◽  
High Energy ◽  
Cascade Model ◽  
Point Sources ◽  
Spectral Energy ◽  
Observation Data ◽  
Cherenkov Telescopes ◽  
The Universe

The intrinsic spectra of some distant blazars known as “extreme TeV blazars” have shown a hint at an anomalous hardening in the TeV energy region. Several extragalactic propagation models have been proposed to explain this possible excess transparency of the Universe to gamma-rays starting from a model which assumes the existence of so-called axion-like particles (ALPs) and the new process of gamma-ALP oscillations. Alternative models suppose that some of the observable gamma-rays are produced in the intergalactic cascades. This work focuses on investigating the spectral and angular features of one of the cascade models, the Intergalactic Hadronic Cascade Model (IHCM) in the contemporary astrophysical models of Extragalactic Magnetic Field (EGMF). For IHCM, EGMF largely determines the deflection of primary cosmic rays and electrons of intergalactic cascades and, thus, is of vital importance. Contemporary Hackstein models are considered in this paper and compared to the model of Dolag. The models assumed are based on simulations of the local part of large-scale structure of the Universe and differ in the assumptions for the seed field. This work provides spectral energy distributions (SEDs) and angular extensions of two extreme TeV blazars, 1ES 0229+200 and 1ES 0414+009. It is demonstrated that observable SEDs inside a typical point spread function of imaging atmospheric Cherenkov telescopes (IACTs) for IHCM would exhibit a characteristic high-energy attenuation compared to the ones obtained in hadronic models that do not consider EGMF, which makes it possible to distinguish among these models. At the same time, the spectra for IHCM models would have longer high energy tails than some available spectra for the ALP models and the universal spectra for the Electromagnetic Cascade Model (ECM). The analysis of the IHCM observable angular extensions shows that the sources would likely be identified by most IACTs not as point sources but rather as extended ones. These spectra could later be compared with future observation data of such instruments as Cherenkov Telescope Array (CTA) and LHAASO.

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