High Energy Cosmic-Ray Showers in Nuclear Emulsions

1951 ◽  
Vol 81 (2) ◽  
pp. 239-244 ◽  
Author(s):  
L. S. Osborne
Keyword(s):  
Cosmic Ray ◽  
High Energy ◽  
Nuclear Emulsions

scholarly journals Diffuse γ-ray emission toward the massive star-forming region, W40

2020 ◽  
Vol 639 ◽  
pp. A80
Author(s):  
Xiao-Na Sun ◽  
Rui-Zhi Yang ◽  
Yun-Feng Liang ◽  
Fang-Kun Peng ◽  
Hai-Ming Zhang ◽  
...  
Keyword(s):  
Cosmic Ray ◽  
High Energy ◽  
Young Star ◽  
Gas Content ◽  
Large Area ◽  
Stellar Cluster ◽  
Production Region ◽  
Star Forming ◽  
Photon Index ◽  
Young Star Clusters

We report the detection of high-energy γ-ray signal towards the young star-forming region, W40. Using 10-yr Pass 8 data from the Fermi Large Area Telescope (Fermi-LAT), we extracted an extended γ-ray excess region with a significance of ~18σ. The radiation has a spectrum with a photon index of 2.49 ± 0.01. The spatial correlation with the ionized gas content favors the hadronic origin of the γ-ray emission. The total cosmic-ray (CR) proton energy in the γ-ray production region is estimated to be the order of 1047 erg. However, this could be a small fraction of the total energy released in cosmic rays (CRs) by local accelerators, presumably by massive stars, over the lifetime of the system. If so, W40, together with earlier detections of γ-rays from Cygnus cocoon, Westerlund 1, Westerlund 2, NGC 3603, and 30 Dor C, supports the hypothesis that young star clusters are effective CR factories. The unique aspect of this result is that the γ-ray emission is detected, for the first time, from a stellar cluster itself, rather than from the surrounding “cocoons”.

scholarly journals Properties of Elementary Particle Fluxes in Primary Cosmic Rays Measured with the Alpha Magnetic Spectrometer on the International Space Station

2019 ◽  
Vol 209 ◽  
pp. 01007
Author(s):  
Francesco Nozzoli
Keyword(s):  
Electron Flux ◽  
Space Station ◽  
Cosmic Ray ◽  
High Energy ◽  
Precision Measurements ◽  
High Energy Electrons ◽  
Electrons And Positrons ◽  
Positron Flux ◽  
Rigidity Dependence ◽  
Alpha Magnetic Spectrometer

Precision measurements by AMS of the fluxes of cosmic ray positrons, electrons, antiprotons, protons as well as their rations reveal several unexpected and intriguing features. The presented measurements extend the energy range of the previous observations with much increased precision. The new results show that the behavior of positron flux at around 300 GeV is consistent with a new source that produce equal amount of high energy electrons and positrons. In addition, in the absolute rigidity range 60–500 GV, the antiproton, proton, and positron fluxes are found to have nearly identical rigidity dependence and the electron flux exhibits different rigidity dependence.

scholarly journals UVscope and its application aboard the ASTRI-Horn telescope

2021 ◽  
Author(s):  
Maria Concetta Maccarone ◽  
Giovanni La Rosa ◽  
Osvaldo Catalano ◽  
Salvo Giarrusso ◽  
Alberto Segreto ◽  
...  
Keyword(s):  
Gamma Ray ◽  
Single Photon ◽  
Photon Counting ◽  
Light Flux ◽  
Cosmic Ray ◽  
High Energy ◽  
Wide Field ◽  
High Energy Astrophysics ◽  
Single Photon Counting ◽  
Photon Counting Mode

AbstractUVscope is an instrument, based on a multi-pixel photon detector, developed to support experimental activities for high-energy astrophysics and cosmic ray research. The instrument, working in single photon counting mode, is designed to directly measure light flux in the wavelengths range 300-650 nm. The instrument can be used in a wide field of applications where the knowledge of the nocturnal environmental luminosity is required. Currently, one UVscope instrument is allocated onto the external structure of the ASTRI-Horn Cherenkov telescope devoted to the gamma-ray astronomy at very high energies. Being co-aligned with the ASTRI-Horn camera axis, UVscope can measure the diffuse emission of the night sky background simultaneously with the ASTRI-Horn camera, without any interference with the main telescope data taking procedures. UVscope is properly calibrated and it is used as an independent reference instrument for test and diagnostic of the novel ASTRI-Horn telescope.

scholarly journals The theory of cosmic ray scattering on pre-existing MHD modes meets data

2021 ◽  
Vol 502 (4) ◽  
pp. 5821-5838
Author(s):  
Ottavio Fornieri ◽  
Daniele Gaggero ◽  
Silvio Sergio Cerri ◽  
Pedro De La Torre Luque ◽  
Stefano Gabici
Keyword(s):  
Diffusion Coefficients ◽  
Galactic Halo ◽  
Dominant Role ◽  
Cosmic Ray ◽  
High Energy ◽  
Scattering Rate ◽  
Equilibrium Spectrum ◽  
Galactic Cosmic Ray ◽  
Comprehensive Study ◽  
Ray Scattering

ABSTRACT We present a comprehensive study about the phenomenological implications of the theory describing Galactic cosmic ray scattering on to magnetosonic and Alfvénic fluctuations in the GeV−PeV domain. We compute a set of diffusion coefficients from first principles, for different values of the Alfvénic Mach number and other relevant parameters associated with both the Galactic halo and the extended disc, taking into account the different damping mechanisms of turbulent fluctuations acting in these environments. We confirm that the scattering rate associated with Alfvénic turbulence is highly suppressed if the anisotropy of the cascade is taken into account. On the other hand, we highlight that magnetosonic modes play a dominant role in Galactic confinement of cosmic rays up to PeV energies. We implement the diffusion coefficients in the numerical framework of the dragon code, and simulate the equilibrium spectrum of different primary and secondary cosmic ray species. We show that, for reasonable choices of the parameters under consideration, all primary and secondary fluxes at high energy (above a rigidity of $\simeq 200 \, \mathrm{GV}$) are correctly reproduced within our framework, in both normalization and slope.

scholarly journals The interstellar medium in young supernova remnants: key to the production of cosmic X-rays and $\gamma $-rays

2021 ◽  
Vol 366 (6) ◽  
Author(s):  
Hidetoshi Sano ◽  
Yasuo Fukui
Keyword(s):  
Interstellar Medium ◽  
Supernova Remnants ◽  
Cosmic Ray ◽  
High Energy ◽  
X Rays ◽  
Interstellar Gas ◽  
High Energy Radiation ◽  
Dense Cores ◽  
The Relationship ◽  
Turbulent Velocity Field

AbstractWe review recent progress in elucidating the relationship between high-energy radiation and the interstellar medium (ISM) in young supernova remnants (SNRs) with ages of ∼2000 yr, focusing in particular on RX J1713.7−3946 and RCW 86. Both SNRs emit strong nonthermal X-rays and TeV $\gamma $ γ -rays, and they contain clumpy distributions of interstellar gas that includes both atomic and molecular hydrogen. We find that shock–cloud interactions provide a viable explanation for the spatial correlation between the X-rays and ISM. In these interactions, the supernova shocks hit the typically pc-scale dense cores, generating a highly turbulent velocity field that amplifies the magnetic field up to 0.1–1 mG. This amplification leads to enhanced nonthermal synchrotron emission around the clumps, whereas the cosmic-ray electrons do not penetrate the clumps. Accordingly, the nonthermal X-rays exhibit a spatial distribution similar to that of the ISM on the pc scale, while they are anticorrelated at sub-pc scales. These results predict that hadronic $\gamma $ γ -rays can be emitted from the dense cores, resulting in a spatial correspondence between the $\gamma $ γ -rays and the ISM. The current pc-scale resolution of $\gamma $ γ -ray observations is too low to resolve this correspondence. Future $\gamma $ γ -ray observations with the Cherenkov Telescope Array will be able to resolve the sub-pc-scale $\gamma $ γ -ray distribution and provide clues to the origin of these cosmic $\gamma $ γ -rays.

scholarly journals High energy cosmic ray interactions and UHECR composition problem

2019 ◽  
Vol 210 ◽  
pp. 02001
Author(s):  
Sergey Ostapchenko
Keyword(s):  
Experimental Data ◽  
Monte Carlo ◽  
Cosmic Rays ◽  
Cosmic Ray ◽  
High Energy ◽  
Ultra High Energy ◽  
Hadronic Interactions ◽  
High Energy Cosmic Rays ◽  
Cosmic Ray Interactions ◽  
Composition Problem

The differences between contemporary Monte Carlo generators of high energy hadronic interactions are discussed and their impact on the interpretation of experimental data on ultra-high energy cosmic rays (UHECRs) is studied. Key directions for further model improvements are outlined. The prospect for a coherent interpretation of the data in terms of the UHECR composition is investigated.

First measurements of cosmic-ray nuclei at high energy with CREAM

2008 ◽  
Vol 42 (3) ◽  
pp. 403-408 ◽  
Author(s):  
S.P. Wakely ◽  
H.S. Ahn ◽  
P. Allison ◽  
M.G. Bagliesi ◽  
J.J. Beatty ◽  
...  
Keyword(s):  
Cosmic Ray ◽  
High Energy

AN EMPIRICAL MODEL OF PRODUCTION AND ATTENUATION OF FLUORESCENCE LIGHT IN ATMOSPHERE FOR SATELLITE-BASED ULTRA HIGH ENERGY COSMIC RAY EXPERIMENTS

2011 ◽  
Vol 20 (03) ◽  
pp. 299-317
Author(s):  
E. STRAZZERI ◽  
O. CATALANO ◽  
B. SBARUFATTI
Keyword(s):  
Stratospheric Ozone ◽  
Cosmic Ray ◽  
High Energy ◽  
Fluorescence Yield ◽  
Ultra High Energy ◽  
Atmospheric Conditions ◽  
Atmospheric Transmission ◽  
Emission Point ◽  
Geographical Variations ◽  
Fluorescence Light

In the context of detection of Ultra High Energy Cosmic Ray (UHECR) showers from space the details of fluorescence light production and transmission in the atmosphere are given. An analytical model of the fluorescence yield, in dependence on nitrogen molecular parameters and the atmospheric conditions, is presented. Seasonal and geographical variations of the total fluorescence photon yield between 300 nm and 400 nm in air excited by 0.85 MeV electrons are shown as a function of the altitude, using different atmospheric models. In the frame of a satellite-based UHECR experiment the fluorescence yield has been corrected by the overall atmospheric transmission which takes into account, in the simplest approximation, the wavelength-dependent scattering and absorption of the fluorescence light from air molecules, from stratospheric ozone, and from aerosol. The effect of the atmospheric attenuation on the fluorescence yield is shown as a function of the altitude of the emission point of light.

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