scholarly journals High-energy gamma rays and the large-scale distribution of gas and cosmic rays

1985 ◽  
Vol 106 ◽  
pp. 213-218
Author(s):  
W. Hermsen ◽  
J.B.G.M. Bloemen
Keyword(s):  
Cosmic Rays ◽  
Column Density ◽  
Large Scale ◽  
Gamma Ray ◽  
Cosmic Ray ◽  
High Energy ◽  
Interstellar Gas ◽  
Density Maps ◽  
Nuclear Component ◽  
Energy Gamma

The COS-B gamma-ray survey is compared with 12CO and HI surveys in a region containing the Orion complex and in the outer Galaxy. The observed gamma-ray intensities in the Orion region (100 MeV<E<5 GeV) can be ascribed to the interaction of uniformly distributed cosmic rays with the interstellar gas. Calibration of the ratio between H2 column-density and integrated CO line intensity resulted in the value: (3.0±0.7)x102 0 molecules cm-2K -1km -1s. In the outer Galaxy HI column-density maps in three galacto-centric distance ranges are used in combination with COS-B gamma-ray data to determine the radial distribution of the gamma-ray emissivity. A steep negative gradient of the emissivity for the 70 MeV-150 MeV range and an approximately constant (within ~20%) emissivity for the 300 MeV-5 GeV range is found. The result is interpreted as a strong decrease in the cosmic-ray electron density and a near constancy of the nuclear component.

scholarly journals Cosmic Rays and the Dynamic Balance in the Large Magellanic Cloud

1990 ◽  
Vol 123 ◽  
pp. 537-541
Author(s):  
Carl E. Fichtel ◽  
Mehmet E. Ozel ◽  
Robert G. Stone
Keyword(s):  
Cosmic Rays ◽  
Gamma Ray ◽  
Dynamic Balance ◽  
Cosmic Ray ◽  
Large Magellanic Cloud ◽  
High Energy ◽  
Magellanic Cloud ◽  
Density Level ◽  
Energy Gamma ◽  
Galactic Dynamic

AbstractPresent and future measurement of the Large Magellanic Cloud (LMC) particularly in the radio and high energy gamma ray range offer the possibility of understanding the density and distribution of the cosmic rays in a galaxy other than our own and the role that they play in galactic dynamic balance. After a study of the consistency of the measurements and interpretation of the synchrotron radiation from our own galaxy, the cosmic ray distribution for the LMC is calculated under the assumption that the cosmic ray nucleon to electron ratio is the same and the relation to the magnetic fields are the same, although the implications of alternatives are discussed. It is seen that the cosmic ray density level appears to be similar to that in our own galaxy, but varying in position in a manner generally consistent with the concept of correlation with the matter on a broad scale.

Diffuse Gamma Rays of Galactic and Extragalactic Origin: Preliminary Results from EGRET

1996 ◽  
Vol 168 ◽  
pp. 279-288
Author(s):  
P. Sreekumar ◽  
D.A. Kniffen
Keyword(s):  
Gamma Rays ◽  
Gamma Ray ◽  
Cosmic Ray ◽  
High Energy ◽  
Emission Model ◽  
Diffuse Emission ◽  
Interstellar Gas ◽  
Cosmic Ray Interactions ◽  
Galactic Model ◽  
Energy Gamma

The all-sky survey in high energy gamma rays (E&gt;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.

scholarly journals TAIGA - a hybrid array for high energy gamma astronomy and cosmic ray physics

2018 ◽  
Vol 191 ◽  
pp. 01007 ◽  
Author(s):  
N. Budnev ◽  
I. Astapov ◽  
P. Bezyazeekov ◽  
V. Boreyko ◽  
A. Borodin ◽  
...  
Keyword(s):  
Cosmic Rays ◽  
Gamma Ray ◽  
High Sensitivity ◽  
Cosmic Ray ◽  
High Energy ◽  
Gamma Ray Astronomy ◽  
Local Sources ◽  
Gamma Astronomy ◽  
Energy Gamma ◽  
The Given

The physics motivations and advantages of the new TAIGA (Tunka Advanced Instrument for cosmic ray physics and Gamma Astronomy) detector are presented. TAIGA aims at gamma-ray astronomy at energies from a few TeV to several PeV, as well as cosmic ray physics from 100 TeV to several EeV. For the energy range 30 – 200 TeV the sensitivity of 10 km2 area TAIGA array for the detection of local sources is expected to be 5 × 10-14 erg cm-2 sec-1 for 300 h of observations. Reconstruction of the given EAS energy, incoming direction and its core position, based on the timing TAIGA-HiSCORE data, allows one to increase a distance between the IACTs up to 600-1000 m. The low investments together with the high sensitivity for energies ≥ 30-50 TeV make this pioneering technique very attractive for exploring the galactic PeVatrons and cosmic rays. At present the TAIGA first stage has been constructed in Tunka valley, 50 km West from the Lake Baikal. The first experimental results of the TAIGA first stage are presented.

scholarly journals Sir Arnold Whittaker Wolfendale. 25 June 1927—21 December 2020

2021 ◽  
Author(s):  
Richard S. Ellis ◽  
Alan A. Watson
Keyword(s):  
Cosmic Rays ◽  
Particle Physics ◽  
Gamma Ray ◽  
Cosmic Ray ◽  
High Energy ◽  
Intermediate Energy ◽  
Public Understanding ◽  
Interstellar Gas ◽  
High Energy Cosmic Rays ◽  
Cosmic Ray Interactions

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.

scholarly journals Recent Status of High-Energy Gamma-Ray Astronomy

2003 ◽  
Vol 214 ◽  
pp. 382-386
Author(s):  
Masato Takita
Keyword(s):  
Cosmic Rays ◽  
Gamma Ray ◽  
High Energy ◽  
Gamma Ray Astronomy ◽  
High Energy Gamma ◽  
Energy Gamma

Sub-TeV and TeV energy gamma-ray astronomy reveals non-thermal gamma-ray pictures of our universe and serve as a probe to understand the origin, acceleration and propagation of cosmic rays. Recent status of ground-based high-energy gamma-ray astronomy is reviewed.

scholarly journals On the flux of high-energy cosmogenic neutrinos and the influence of the extragalactic magnetic field

2019 ◽  
Vol 488 (1) ◽  
pp. L119-L122 ◽  
Author(s):  
David Wittkowski ◽  
Karl-Heinz Kampert
Keyword(s):  
Magnetic Field ◽  
Cosmic Rays ◽  
Large Scale ◽  
Neutrino Flux ◽  
Cosmic Ray ◽  
High Energy ◽  
Observation Time ◽  
Cosmological Time ◽  
Cosmic Background ◽  
The Universe

ABSTRACT Cosmogenic neutrinos originate from interactions of cosmic rays propagating through the universe with cosmic background photons. Since both high-energy cosmic rays and cosmic background photons exist, the existence of high-energy cosmogenic neutrinos is certain. However, their flux has not been measured so far. Therefore, we calculated the flux of high-energy cosmogenic neutrinos arriving at the Earth on the basis of elaborate 4D simulations that take into account three spatial degrees of freedom and the cosmological time-evolution of the universe. Our predictions for this neutrino flux are consistent with the recent upper limits obtained from large-scale cosmic-ray experiments. We also show that the extragalactic magnetic field has a strong influence on the neutrino flux. The results of this work are important for the design of future neutrino observatories, since they allow to assess the detector volume and observation time that are necessary to detect high-energy cosmogenic neutrinos in the near future. An observation of such neutrinos would push multimessenger astronomy to hitherto unachieved energy scales.

Development of the Buckland Park Cosmic Ray Air Shower Array for Ultra High Energy Gamma Ray Astronomy

1986 ◽  
Vol 6 (3) ◽  
pp. 335-338 ◽  
Author(s):  
D. Ciampa ◽  
R. W. Clay ◽  
C. L. Corani ◽  
P. G. Edwards ◽  
J. R. Patterson
Keyword(s):  
Gamma Ray ◽  
Cosmic Ray ◽  
High Energy ◽  
Ultra High Energy ◽  
Gamma Ray Astronomy ◽  
Air Shower ◽  
High Energy Gamma ◽  
Energy Gamma ◽  
Shower Array ◽  
Air Shower Array

AbstractThe Buckland Park air shower array is being developed particularly for use as an ultra-high-energy gamma ray astronomy telescope. The properties of this instrument are described with an emphasis on improvements being made to its angular resolution. Some early data are presented to illustrate the way in which the data obtained will be used.

scholarly journals The signature of large scale structures on the very high energy gamma ray sky

2007 ◽  
Vol 2007 (04) ◽  
pp. 013-013 ◽  
Author(s):  
A Cuoco ◽  
S Hannestad ◽  
T Haugbølle ◽  
G Miele ◽  
P D Serpico ◽  
...  
Keyword(s):  
Large Scale ◽  
Gamma Ray ◽  
High Energy ◽  
Large Scale Structures ◽  
High Energy Gamma ◽  
Very High Energy ◽  
Energy Gamma ◽  
Scale Structures ◽  
Very High
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