Flux Limit on Cosmic-Ray Magnetic Monopoles from a Large Area Induction Detector

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”.

Download Full-text

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

Monthly Notices of the Royal Astronomical Society Letters ◽

10.1093/mnrasl/slz185 ◽

2019 ◽

Vol 495 (1) ◽

pp. L124-L128 ◽

Cited By ~ 2

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.

Download Full-text

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

Physical Review D ◽

10.1103/physrevd.98.022006 ◽

2018 ◽

Vol 98 (2) ◽

Cited By ~ 4

Author(s):

M. N. Mazziotta ◽

F. Costanza ◽

A. Cuoco ◽

F. Gargano ◽

F. Loparco ◽

...

Keyword(s):

Cosmic Ray ◽

Large Area ◽

Positron Spectrum

Download Full-text

An All-sky Search for Cosmic-ray Proton Anisotropy with the Fermi Large Area Telescope

10.22323/1.358.0144 ◽

2019 ◽

Author(s):

Justin Vandenbroucke ◽

Matthew Meehan ◽

Keyword(s):

Cosmic Ray ◽

Large Area

Download Full-text

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

Solid State Nuclear Track Detectors ◽

10.1016/b978-0-08-026509-4.50170-7 ◽

1982 ◽

pp. 863-866 ◽

Cited By ~ 1

Author(s):

W. Heinrich ◽

M. Simon ◽

H.O. Tittel ◽

J.F. Ormes ◽

V.K. Balasubrahmanyan ◽

...

Keyword(s):

Cosmic Ray ◽

Large Area

Download Full-text

The Homestake Large Area Scintillation Detector and cosmic ray telescope

10.1063/1.35161 ◽

1985 ◽

Author(s):

M. L. Cherry ◽

S. Corbato ◽

D. Kieda ◽

K. Lande ◽

C. K. Lee ◽

...

Keyword(s):

Scintillation Detector ◽

Cosmic Ray ◽

Large Area

Download Full-text

USING THE WESTERBORK RADIO OBSERVATORY TO DETECT UHE COSMIC PARTICLES INTERACTING ON THE MOON

International Journal of Modern Physics A ◽

10.1142/s0217751x06033532 ◽

2006 ◽

Vol 21 (supp01) ◽

pp. 147-152

Author(s):

J. BACELAR ◽

O. SCHOLTEN ◽

A. G. de BRUYN ◽

H. FALCKE

Keyword(s):

Cosmic Rays ◽

Radio Telescope ◽

Radio Pulse ◽

Lunar Regolith ◽

Neutrino Flux ◽

Cosmic Ray ◽

High Energy ◽

Observation Time ◽

Flux Limit ◽

Null Result

Ultra-High-Energy (UHE) particles of cosmological origin (cosmic-rays and neutrinos), carry information on the most spectacular events known. These extremely energetic (energies larger than 1 ZeV= 1021 eV) cosmic-rays or neutrinos initiate in the lunar regolith a cascade of charged particles which acts as a radio pulse emitter. The instantaneous power produced can be detected here at the Earth, with a radio telescope operating at the optimal frequency window around 150 MHz. Using 12 telescopes of the Westerbork Synthesis Radio Telescope, WSRT, with a field of view covering the whole lunar surface, our calculations show that one should identify 10 UHE events within an observation time of 500 hours, assuming an extrapolated power law dependence of the highest ever measured cosmic-ray events, around an energy of 1020 eV. A null result will determine unambiguously the GKZ effect for the cosmic-ray flux and improve the present world upper limit on the neutrino flux above 1 ZeV, by three orders of magnitude, allowing for the first time to test the Waxman-Bahcall neutrino flux limit.

Download Full-text