scholarly journals Search for features in the cosmic-ray electron and positron spectrum measured by the Fermi Large Area Telescope

2018 ◽  
Vol 98 (2) ◽  
Author(s):  
M. N. Mazziotta ◽  
F. Costanza ◽  
A. Cuoco ◽  
F. Gargano ◽  
F. Loparco ◽  
...  
Keyword(s):  
Cosmic Ray ◽  
Large Area ◽  
Positron Spectrum

scholarly journals Cosmic-ray electron-positron spectrum from 7 GeV to 2 TeV with the Fermi Large Area Telescope

2017 ◽  
Vol 95 (8) ◽  
Author(s):  
S. Abdollahi ◽  
M. Ackermann ◽  
M. Ajello ◽  
W. B. Atwood ◽  
L. Baldini ◽  
...  
Keyword(s):  
Cosmic Ray ◽  
Large Area ◽  
Electron Positron ◽  
Positron Spectrum

scholarly journals Search for dark matter signatures in the cosmic-ray electron and positron spectrum measured by the Fermi Large Area Telescope

2019 ◽  
Author(s):  
Mario Nicola Mazziotta ◽  
Alessandro Cuoco ◽  
Pedro De La Torre Luque ◽  
Francesco Loparco ◽  
Davide Serini ◽  
...  
Keyword(s):  
Dark Matter ◽  
Cosmic Ray ◽  
Large Area ◽  
Positron Spectrum

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 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 >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 LARGE AREA COSMIC RAY ISOTOPE EXPERIMENT USING CHERENKOV RANGE DETECTOR TECHNIQUES

1982 ◽  
pp. 863-866 ◽  
Author(s):  
W. Heinrich ◽  
M. Simon ◽  
H.O. Tittel ◽  
J.F. Ormes ◽  
V.K. Balasubrahmanyan ◽  
...  
Keyword(s):  
Cosmic Ray ◽  
Large Area

The Homestake Large Area Scintillation Detector and cosmic ray telescope

1985 ◽  
Author(s):  
M. L. Cherry ◽  
S. Corbato ◽  
D. Kieda ◽  
K. Lande ◽  
C. K. Lee ◽  
...  
Keyword(s):  
Scintillation Detector ◽  
Cosmic Ray ◽  
Large Area

scholarly journals A large area cosmic ray detector for the inspection of hidden high-Z materials inside containers

2013 ◽  
Vol 409 ◽  
pp. 012046 ◽  
Author(s):  
S Riggi ◽  
V Antonuccio ◽  
M Bandieramonte ◽  
U Becciani ◽  
F Belluomo ◽  
...  
Keyword(s):  
Cosmic Ray ◽  
Large Area

scholarly journals Analytical model for cluster radio relics

2020 ◽  
Vol 493 (2) ◽  
pp. 2306-2317 ◽  
Author(s):  
M Brüggen ◽  
F Vazza
Keyword(s):  
Magnetic Field ◽  
Flux Distribution ◽  
Cosmic Ray ◽  
Analytical Models ◽  
Physical Parameters ◽  
Mass Relation ◽  
Intracluster Medium ◽  
Large Area ◽  
Shock Dynamics ◽  
The Magnetic Field

ABSTRACT Radio relics are vast synchrotron sources that sit on the outskirts of merging galaxy clusters. In this work we model their formation using a Press–Schechter formalism to simulate merger rates, analytical models for the intracluster medium and the shock dynamics, as well as a simple model for the cosmic ray electrons at the merger shocks. We show that the statistical properties of the population of radio relics are strongly dependent on key physical parameters, such as the acceleration efficiency, the magnetic field strength at the relic, the geometry of the relic and the duration of the electron acceleration at merger shocks. It turns out that the flux distribution as well as the power–mass relation can constrain key parameters of the intracluster medium. With the advent of new large-area radio surveys, statistical analyses of radio relics will complement what we have learned from observations of individual objects.

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