The anisotropy of cosmic ray flux in Large Area Air Shower experiments

2008 ◽  
Vol 175-176 ◽  
pp. 459-462 ◽  
Author(s):  
C. Noda ◽  
A. Iyono ◽  
H. Matsumoto ◽  
M. Masuda ◽  
M. Okita ◽  
...  
Keyword(s):  
Cosmic Ray ◽  
Large Area ◽  
Air Shower ◽  
Cosmic Ray Flux

scholarly journals The HiSCORE Project

2014 ◽  
Vol 1 (1) ◽  
pp. 283-287 ◽  
Author(s):  
M. Tluczykont ◽  
M. Brückner ◽  
N. Budnev ◽  
O. Chvalaev ◽  
A. Dyachok ◽  
...  
Keyword(s):  
Cosmic Rays ◽  
Energy Range ◽  
Cosmic Ray ◽  
Central Question ◽  
Large Area ◽  
Particle Detectors ◽  
Air Shower ◽  
The Status ◽  
Hybrid Detector ◽  
Cosmic Origin

A central question of Astroparticle Physics, the origin of cosmic rays, still remains unsolved. HiSCORE (Hundred*i Square-km Cosmic ORigin Explorer) is a concept for a large-area wide-angle non-imaging air shower detector, addressing this question by searching for cosmic ray pevatrons in the energy range from 10TeV to few PeV and cosmic rays in the energy range above 100TeV. In the framework of the Tunka-HiSCORE project, first prototypes have been deployed on the site of the Tunka-133 experiment, where we plan to install an engineering array covering an area of the order of 1km<sup>2</sup>. On the same site, also imaging and particle detectors are planned, potentially allowing a future hybrid detector system. Here we present the HiSCORE detector principle, its potential for cosmic ray origin search and the status of ongoing activities in the framework of the Tunka-HiSCORE experiment.

scholarly journals The cosmic-ray content of the Orion-Eridanus superbubble

2020 ◽  
Vol 635 ◽  
pp. A96 ◽  
Author(s):  
T. Joubaud ◽  
I. A. Grenier ◽  
J. M. Casandjian ◽  
T. Tolksdorf ◽  
R. Schlickeiser
Keyword(s):  
Cosmic Rays ◽  
Galactic Plane ◽  
Cosmic Ray ◽  
Significant Loss ◽  
Particle Energy ◽  
Stellar Winds ◽  
The Sun ◽  
Large Area ◽  
Average Spectrum ◽  
Cosmic Ray Flux

Aims. The nearby Orion-Eridanus superbubble, which was blown by multiple supernovae several million years ago, has likely produced cosmic rays. Its turbulent medium is still energised by massive stellar winds and it can impact cosmic-ray transport locally. The γ radiation produced in interactions between cosmic rays and interstellar gas can be used to compare the cosmic-ray spectrum in the superbubble and in other regions near the Sun. It can reveal spectral changes induced in GeV to TeV cosmic rays by the past and present stellar activity in the superbubble. Methods. We used ten years of data from the Fermi Large Area Telescope (LAT) in the 0.25–63 GeV energy range to study the closer (Eridanus) end of the superbubble at low Galactic latitudes. We modelled the spatial and spectral distributions of the γ rays produced in the different gas phases (atomic, molecular, dark, and ionised) of the clouds found in this direction. The model included other non-gaseous components to match the data. Results. We found that the γ-ray emissivity spectrum of the gas along the outer rim and in a shell inside the superbubble is consistent with the average spectrum measured in the solar neighbourhood. It is also consistent with the cosmic-ray spectrum directly measured in the Solar System. This homogeneity calls for a detailed assessment of the recent supernova rate and current census of massive stellar winds in the superbubble in order to estimate the epoch and rate of cosmic-ray production and to constrain the transport conditions that can lead to such homogeneity and little re-acceleration. We also found significant evidence that a diffuse atomic cloud lying outside the superbubble, at a height of 200–250 pc below the Galactic plane, is pervaded by a 34% lower cosmic-ray flux, but with the same particle energy distribution as the local one. Super-GeV cosmic rays should freely cross such a light and diffuse cirrus cloud without significant loss or spectral distorsion. We tentatively propose that the cosmic-ray loss relates to the orientation of the magnetic field lines threading the cirrus, which point towards the halo according to the dust polarisation data from Planck. Finally, we gathered the present emissivity measurements with previous estimates obtained around the Sun to show how the local cosmic-ray flux decreases with Galactic height and to compare this trend with model predictions.

scholarly journals PeV Emission of the Crab Nebula: Constraints on the Proton Content in Pulsar Wind and Implications

2021 ◽  
Vol 922 (2) ◽  
pp. 221
Author(s):  
Ruo-Yu Liu ◽  
Xiang-Yu Wang
Keyword(s):  
Energy Content ◽  
Crab Nebula ◽  
Cosmic Ray ◽  
Ultrahigh Energy ◽  
Pulsar Wind Nebulae ◽  
Air Shower ◽  
Pulsar Wind ◽  
The Crab Nebula ◽  
Pulsar Winds ◽  
Cosmic Ray Flux

Abstract Recently, two photons from the Crab Nebula with energy of approximately 1 PeV were detected by the Large High Altitude Air Shower Observatory (LHAASO), opening an ultrahigh-energy window for studying pulsar wind nebulae (PWNe). Remarkably, the LHAASO spectrum at the highest-energy end shows a possible hardening, which could indicate the presence of a new component. A two-component scenario with a main electron component and a secondary proton component has been proposed to explain the whole spectrum of the Crab Nebula, requiring a proton energy of 1046–1047 erg remaining in the present Crab Nebula. In this paper, we study the energy content of relativistic protons in pulsar winds using the LHAASO data of the Crab Nebula, considering the effect of diffusive escape of relativistic protons. Depending on the extent of the escape of relativistic protons, the total energy of protons lost in the pulsar wind could be 10–100 times larger than that remaining in the nebula presently. We find that the current LHAASO data allow up to (10–50)% of the spindown energy of pulsars being converted into relativistic protons. The escaping protons from PWNe could make a considerable contribution to the cosmic-ray flux of 10–100 PeV. We also discuss the leptonic scenario for the possible spectral hardening at PeV energies.

A NEW STUDY ON THE ENERGY SPECTRUM AND COMPOSITION OF PRIMARY COSMIC RAY FLUX AT ENERGIES ~ 1014 – 1016 EV USING THE GRAPES-3 ARRAY AT OOTY

2005 ◽  
Vol 20 (29) ◽  
pp. 6852-6854
Author(s):  
S. C. TONWAR ◽  
S. K. GUPTA ◽  
D. K. MOHANTY ◽  
P. K. MOHANTY ◽  
K. SIVAPRASAD ◽  
...  
Keyword(s):  
Energy Spectrum ◽  
Multiplicity Distribution ◽  
Cosmic Ray ◽  
Size Spectrum ◽  
Muon Detector ◽  
Reliable Measurement ◽  
Air Shower ◽  
Shower Size ◽  
Cosmic Ray Flux ◽  
Shower Array

Data collected with the 217-detector air shower array and the 560 m2 area tracking muon detector, being operated at Ooty in southern India by the India-Japan (Tata Institute-Osaka City University) collaboration, GRAPES, have been analyzed to study the shape of the energy spectrum and the composition around the knee. It is shown that the muon multiplicity distribution, observed with the highly modular muon detector, permits a relatively reliable measurement on the composition of primary flux which then helps in a more accurate reconstruction of the energy spectrum from the observed shower size spectrum. The highlights of the GRAPES array, the analysis procedure and the results are presented.

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 Cosmic ray flux and lockdown due to COVID-19 in Kolkata – Any correlation?

Pramana ◽  
2021 ◽  
Vol 95 (2) ◽  
Author(s):  
A Sen ◽  
S Chatterjee ◽  
S Roy ◽  
R Biswas ◽  
S Das ◽  
...  
Keyword(s):  
Cosmic Ray ◽  
Cosmic Ray Flux

scholarly journals A possible radio signal of annihilating dark matter in the Abell 4038 cluster

2019 ◽  
Vol 495 (1) ◽  
pp. L124-L128 ◽  
Author(s):  
Man Ho Chan ◽  
Chak Man Lee
Keyword(s):  
Dark Matter ◽  
Cross Section ◽  
Radio Signal ◽  
Dark Matter Particle ◽  
Cosmic Ray ◽  
Annihilation Cross Section ◽  
Radio Continuum ◽  
Test Statistic ◽  
Large Area ◽  
Dark Matter Annihilation

ABSTRACT In the past decade, some telescopes [e.g. Fermi-Large Area Telescope (LAT), Alpha Magnetic Spectrometer(AMS), and Dark Matter Particle Explorer(DAMPE)] were launched to detect the signals of annihilating dark matter in our Galaxy. Although some excess of gamma-rays, antiprotons, and electrons/positrons have been reported and claimed as dark matter signals, the uncertainties of Galactic pulsars’ contributions are still too large to confirm the claims. In this Letter, we report a possible radio signal of annihilating dark matter manifested in the archival radio continuum spectral data of the Abell 4038 cluster. By assuming the thermal annihilation cross-section and comparing the dark matter annihilation model with the null hypothesis (cosmic ray emission without dark matter annihilation), we get very large test statistic values &gt;45 for four popular annihilation channels, which correspond to more than 6.5σ statistical preference. This provides a very strong evidence for the existence of annihilating dark matter. In particular, our results also support the recent claims of dark matter mass m ≈ 30–50 GeV annihilating via the bb̄ quark channel with the thermal annihilation cross-section.

A correction to previously quoted cosmic ray flux values

1957 ◽  
Vol 6 (3) ◽  
pp. 748-750 ◽  
Author(s):  
C. J. Waddington
Keyword(s):  
Cosmic Ray ◽  
Cosmic Ray Flux

Long-term negative trend in cosmic ray flux

2000 ◽  
Vol 105 (A1) ◽  
pp. 9-17 ◽  
Author(s):  
Yuri I. Stozhkov ◽  
Peter E. Pokrevsky ◽  
Victor P. Okhlopkov
Keyword(s):  
Cosmic Ray ◽  
Negative Trend ◽  
Cosmic Ray Flux

scholarly journals Probing the Galactic cosmic ray flux with submillimeter and gamma ray data

2008 ◽  
Author(s):  
S. Casanova ◽  
S. Gabici ◽  
F. A. Aharonian ◽  
K. Torii ◽  
Y. Fukui ◽  
...  
Keyword(s):  
Gamma Ray ◽  
Cosmic Ray ◽  
Galactic Cosmic Ray ◽  
Cosmic Ray Flux
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