scholarly journals Gamma-ray astrophysics in the MeV range

Author(s):  
Alessandro De Angelis ◽  
Vincent Tatischeff ◽  
Andrea Argan ◽  
Søren Brandt ◽  
Andrea Bulgarelli ◽  
...  

AbstractThe energy range between about 100 keV and 1 GeV is of interest for a vast class of astrophysical topics. In particular, (1) it is the missing ingredient for understanding extreme processes in the multi-messenger era; (2) it allows localizing cosmic-ray interactions with background material and radiation in the Universe, and spotting the reprocessing of these particles; (3) last but not least, gamma-ray emission lines trace the formation of elements in the Galaxy and beyond. In addition, studying the still largely unexplored MeV domain of astronomy would provide for a rich observatory science, including the study of compact objects, solar- and Earth-science, as well as fundamental physics. The technological development of silicon microstrip detectors makes it possible now to detect MeV photons in space with high efficiency and low background. During the last decade, a concept of detector (“ASTROGAM”) has been proposed to fulfil these goals, based on a silicon hodoscope, a 3D position-sensitive calorimeter, and an anticoincidence detector. In this paper we stress the importance of a medium size (M-class) space mission, dubbed “ASTROMEV”, to fulfil these objectives.

1996 ◽  
Vol 168 ◽  
pp. 279-288
Author(s):  
P. Sreekumar ◽  
D.A. Kniffen

The all-sky survey in high energy gamma rays (E>30 MeV) carried out by the Energetic Gamma Ray Experiment Telescope (EGRET) aboard the Compton Gamma Ray Observatory provides for the first time an opportunity to examine in detail diffuse gamma-ray emission of extra-galactic origin. The observed diffuse emission at high galactic latitudes is generally assumed to have a galactic component arising from cosmic-ray interactions with the local interstellar gas and radiation, in addition to an isotropic component presumably of extragalactic origin. The galactic component can be estimated from a model of the interstellar medium and cosmic-ray distribution. Since the derived extragalactic spectrum depends very much on the success of our galactic model, the consistency of the galactic diffuse emission model is examined both spectrally and spatially with existing EGRET observations. In conjunction with this model, EGRET observations of the high latitude emission are used to examine the flux and spectrum of the residual extragalactic emission. This residual emission could be either truly diffuse in origin or could arise from accumulated emission from unresolved sources particularly in the light of EGRET observations showing the presence of numerous gamma-ray bright active galactic nuclei.


2018 ◽  
Vol 174 ◽  
pp. 05002 ◽  
Author(s):  
M. Frotin ◽  
P. Gros ◽  
D. Attié ◽  
D. Bernard ◽  
V. Dauvois ◽  
...  

HARPO is a time projection chamber (TPC) demonstrator of a gamma-ray telescope and polarimeter in the MeV-GeV range, for a future space mission. We present the evolution of the TPC performance over a five month sealed-mode operation, by the analysis of cosmic-ray data, followed by the fast and complete recovery of the initial gas properties using a lightweight gas circulation and purification system.


2017 ◽  
Vol 12 (S331) ◽  
pp. 351-356
Author(s):  
Vincent Tatischeff ◽  
Roland Diehl ◽  
Alessandro De Angelis

Abstracte-ASTROGAM is a gamma-ray observatory operating in a broad energy range, 0.15 MeV – 3 GeV, recently proposed as the M5 Medium-size mission of the European Space Agency. It has the potential to revolutionize the astronomy of medium-energy gamma-rays by increasing the number of known sources in this domain by more than an order of magnitude and providing gamma-ray polarization information for many of these sources. In these proceedings, we discuss the expected capacity of the mission to study the physics of supernovae, both thermonuclear and core-collapse, as well as the origin of cosmic rays in SN shocks.


2004 ◽  
Vol 610 (2) ◽  
pp. 868-875 ◽  
Author(s):  
Michiko Ohishi ◽  
Masaki Mori ◽  
Mark Walker

2022 ◽  
Vol 105 (2) ◽  
Author(s):  
Pei-pei Zhang ◽  
Bing-qiang Qiao ◽  
Qiang Yuan ◽  
Shu-wang Cui ◽  
Yi-qing Guo

1985 ◽  
Vol 106 ◽  
pp. 235-236
Author(s):  
A. W. Strong

During its 6.7-year lifetime the COS-B experiment included about 15 months of observations towards latitudes |b|> 20° and covered almost all latitudes from the South to North galactic poles. Studies comparing the local gamma-ray emission with the distribution of gas (Lebrun et al. 1982, Strong et al. 1982) have so far been limited to 10°<|b|< 20°, where the correlation is found to be fairly good and the structured emission can therefore be attributed mainly to cosmic-ray interactions with gas. The extension of this type of analysis to higher latitudes is now possible using the COS-B database.


Author(s):  
Richard S. Ellis ◽  
Alan A. Watson

For over 50 years Arnold Wolfendale was an international leader in the fields of cosmic ray and gamma ray astronomy, making many seminal contributions. His extensive studies of the muon particle culminated in 1965 when, using an installation in the Kolar Gold Mine in India, he played a major role in the first detection of the neutrinos associated with muons produced in the atmosphere. His interests in the origin of high-energy cosmic rays were extensive and required the development of a better understanding of particle physics at energies beyond those accessible at accelerators. Recognizing that high-energy gamma rays can arise from cosmic ray interactions with the interstellar gas, he used early satellite data to argue for the galactic origin of intermediate-energy cosmic rays and for studies of the distribution of molecular hydrogen. His interests in astronomy, which he firmly held to be a branch of physics, drove him to develop a world-class activity in this area at Durham University. This achievement, in part, led to him being appointed Astronomer Royal in 1991. He used this position, and his roles as president of the Royal Astronomical Society, the Institute of Physics and the European Physical Society, to lobby tirelessly for more governmental support for science. He was an early advocate for improvements in the public understanding of science, leading by example. In his later years Arnold's interests extended to cosmology and horology, and he argued against a possible connection between cosmic rays and global warming. A brilliant communicator, Arnold gave a huge number of lectures each year to general audiences, almost to the end of his life.


2019 ◽  
Vol 209 ◽  
pp. 01041
Author(s):  
Margherita Di Santo

DAMPE (DArk Matter Particle Explorer) is a space mission project promoted by the Chinese Academy of Sciences (CAS), in collaboration with Universities and Institutes from China, Italy and Switzerland. The detector is collecting data in a stable sun-synchronous orbit lasting 95 minutes at an altitude of about 500 km. It has been launched in December 17th, 2015, from the Jiuquan Satellite Launch Center, in the Gobi Desert. The main goals of the mission are: indirect search for Dark Matter, looking for signatures in the electron and photon spectra with energies up to 10 TeV; analysis of the flux and composition of primary Cosmic Rays with energies up to hundreds of TeV; high energy gamma-ray astronomy. Preliminary results about the Helium flux and Cosmic Ray composition will be presented and discussed.


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