scholarly journals Cosmic Gamma Ray Constraints on the Indirect Effects of Dark Matter

Particles ◽  
2020 ◽  
Vol 3 (2) ◽  
pp. 336-344 ◽  
Author(s):  
Konstantin M. Belotsky ◽  
Airat Kh. Kamaletdinov ◽  
Ekaterina S. Shlepkina ◽  
Maxim L. Solovyov
Keyword(s):  
Dark Matter ◽  
Gamma Radiation ◽  
Indirect Effects ◽  
Gamma Ray ◽  
Indirect Evidence ◽  
Cosmic Ray ◽  
High Energy ◽  
Observational Constraint ◽  
Atom Model ◽  
Suppression Effects

The observed anomalous excess of high-energy cosmic ray (CR) positrons is widely discussed as possible indirect evidence for dark matter (DM). However, any source of cosmic positrons is inevitably the source of gamma radiation. The least model dependent test of CR anomalies interpretation via DM particles decays (or annihilation) is connected with gamma-ray background due to gamma overproduction in such processes. In this work, we impose an observational constraint on gamma ray production from DM. Then, we study the possible suppression of gamma yield in the DM decays into identical final fermions. Such DM particles arise in the multi-component dark atom model. The influence of the interaction vertices on the gamma suppression was also considered. No essential gamma suppression effects are found. However, some minor ones are revealed.

scholarly journals Astroparticle Physics with H.E.S.S.: recents results and nearfuture prospects

2019 ◽  
Vol 209 ◽  
pp. 01054
Author(s):  
Emmanuel Moulin
Keyword(s):  
Dark Matter ◽  
Gamma Ray ◽  
Lorentz Invariance ◽  
Cosmic Ray ◽  
High Energy ◽  
New Physics ◽  
Galactic Centre ◽  
Astroparticle Physics ◽  
Dark Matter Search ◽  
Physics Program

H.E.S.S. is an array of five Imaging Atmospheric Cherenkov Telescopes located in Namibia. It is designed for observations of astrophysical sources emitting very-high-energy (VHE) gamma rays in the energy range from a few ten GeVs to several ten TeVs. The H.E.S.S. instrument consists of four identical 12 m diameter telescopes and a 28 m diameter telescope placed at the center of the array. An ambitious Astroparticle Physics program is being carried out by the H.E.S.S. collaboration searching for New Physics in the VHE gamma-ray sky. The program includes the search for WIMP dark matter and axion-like particles, tests of Lorentz invariance, cosmic-ray electron measurements, and search for intergalactic magnetic fields. I will present the latest results on dark matter search from the observations of the Galactic Centre region, the search for Lorentz invariance violation with the 2014 flare observation of Markarian 501, and the first measurement of the cosmic-ray electron spectrum up to 20 TeV. The future of the H.E.S.S. Astroparticle Physics program will be discussed.

scholarly journals Helium flux and elemental composition of galactic Cosmic Rays with the DAMPE space mission

2019 ◽  
Vol 209 ◽  
pp. 01041
Author(s):  
Margherita Di Santo
Keyword(s):  
Dark Matter ◽  
Cosmic Rays ◽  
Gamma Ray ◽  
Dark Matter Particle ◽  
Cosmic Ray ◽  
High Energy ◽  
Space Mission ◽  
Galactic Cosmic Rays ◽  
Gobi Desert ◽  
Photon Spectra

DAMPE (DArk Matter Particle Explorer) is a space mission project promoted by the Chinese Academy of Sciences (CAS), in collaboration with Universities and Institutes from China, Italy and Switzerland. The detector is collecting data in a stable sun-synchronous orbit lasting 95 minutes at an altitude of about 500 km. It has been launched in December 17th, 2015, from the Jiuquan Satellite Launch Center, in the Gobi Desert. The main goals of the mission are: indirect search for Dark Matter, looking for signatures in the electron and photon spectra with energies up to 10 TeV; analysis of the flux and composition of primary Cosmic Rays with energies up to hundreds of TeV; high energy gamma-ray astronomy. Preliminary results about the Helium flux and Cosmic Ray composition will be presented and discussed.

scholarly journals Implications of dark matter cascade decay from DAMPE, HESS, Fermi-LAT and AMS02 data

2019 ◽  
Author(s):  
Yu Gao ◽  
Yin-Zhe Ma
Keyword(s):  
Dark Matter ◽  
Gamma Ray ◽  
Decay Channel ◽  
Dark Matter Particle ◽  
Cosmic Ray ◽  
High Energy ◽  
Data Sets ◽  
Spectral Difference ◽  
Cascade Decay ◽  
Scale Down

Abstract Recent high-energy cosmic e± measurement from the DArk Matter Particle Explorer (DAMPE) satellite confirms the deviation of total cosmic ray electron spectrum above 700-900 GeV from a simple power law. In this paper we demonstrate that the cascade decay of dark matter can account for DAMPE’s TeV e+e− spectrum. We select the least constraint DM decay channel into four muons as the benchmark scenario, and perform an analysis with propagation variance in both DM signal and the Milky Way’s electron background. The best-fit of the model is obtained for joint DAMPE, Fermi-LAT, H.E.S.S. high energy electron data sets, and with an $\mathcal {O}(10^{26})$ second decay lifetime, which is consistent with existing gamma ray and cosmic microwave background limits. We compare the spectral difference between the cascade decay of typical final-state channels. The least constrained 4μ channels give good fits to the electron spectrum’s TeV scale down-turn, yet their low energy spectrum has tension with sub-TeV positron data from AMS02. We also consider a three-step cascade decay into eight muons, and also a gamma-ray constrained 4μ, 4b mixed channel, to demonstrate that a further softened cascade decay signal would be required for the agreement with all the data sets.

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 Molecular Clouds Observed by the EGRET Gamma-Ray Telescope

1997 ◽  
Vol 170 ◽  
pp. 22-24 ◽  
Author(s):  
Seth. W. Digel ◽  
Stanley D. Hunter ◽  
Reshmi Mukherjee ◽  
Eugéne J. de Geus ◽  
Isabelle A. Grenier ◽  
...  
Keyword(s):  
Molecular Mass ◽  
Molecular Clouds ◽  
Gamma Ray ◽  
Angular Resolution ◽  
Cosmic Ray ◽  
High Energy ◽  
Background Rejection ◽  
Γ Rays ◽  
Γ Ray ◽  
Production Mechanisms

EGRET, the high-energy γ-ray telescope on the Compton Gamma-Ray Observatory, has the sensitivity, angular resolution, and background rejection necessary to study diffuse γ-ray emission from the interstellar medium (ISM). High-energy γ rays produced in cosmic-ray (CR) interactions in the ISM can be used to determine the CR density and calibrate the CO line as a tracer of molecular mass. Dominant production mechanisms for γ rays of energies ∼30 MeV–30 GeV are the decay of pions produced in collisions of CR protons with ambient matter and Bremsstrahlung scattering of CR electrons.

Detectors for cosmic particles, neutrinos and exotic matter

2020 ◽  
pp. 655-710
Author(s):  
Hermann Kolanoski ◽  
Norbert Wermes
Keyword(s):  
Dark Matter ◽  
Particle Physics ◽  
Cosmic Radiation ◽  
Charged Particles ◽  
Cosmic Ray ◽  
High Energy ◽  
Detection Methods ◽  
Astroparticle Physics ◽  
High Energy Cosmic Rays ◽  
Cosmic Origin

Astroparticle physics deals with the investigation of cosmic radiation using similar detection methods as in particle physics, however, mostly with quite different detector arrangements. In this chapter the detection principles for the different radiation types with cosmic origin are presented, this includes charged particles, gamma radiation, neutrinos and possibly existing Dark Matter. In the case of neutrinos also experiments at accelerators and reactors are included. Examples, which are typical for the different areas, are given for detectors and their properties. For cosmic ray detection apparatuses are deployed above the atmosphere with balloons or satellites or on the ground using the atmosphere as calorimeter in which high-energy cosmic rays develop showers or in underground areas including in water and ice.

scholarly journals Quasielastic Lepton Scattering off Two-Component Dark Matter in Hypercolor Model

Symmetry ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 708 ◽  
Author(s):  
Vitaly Beylin ◽  
Maxim Bezuglov ◽  
Vladimir Kuksa ◽  
Egor Tretiakov
Keyword(s):  
Dark Matter ◽  
Total Cross Section ◽  
Cross Section ◽  
Strong Dependence ◽  
Cosmic Ray ◽  
High Energy ◽  
Dominant Contribution ◽  
Quasielastic Scattering ◽  
Two Component ◽  
The Cross

The interaction of high-energy leptons with components of Dark Matter in a hypercolor model is considered. The possibility of detection, using IceCube secondary neutrinos produced by quasielastic scattering of cosmic ray electrons off hidden mass particles, is investigated. The dominant contribution to the cross section results from diagrams with scalar exchanges. A strong dependence of the total cross section on the Dark Matter components mass is also found.

scholarly journals Gamma-ray counterparts of 2WHSP high-synchrotron-peaked BL Lac objects as possible signatures of ultra-high-energy cosmic ray emission

2020 ◽  
Vol 497 (2) ◽  
pp. 2455-2468
Author(s):  
Michael W Toomey ◽  
Foteini Oikonomou ◽  
Kohta Murase
Keyword(s):  
Energy Range ◽  
Gamma Ray ◽  
Cosmic Ray ◽  
High Energy ◽  
Potential Candidate ◽  
Ultra High Energy ◽  
Bl Lac Objects ◽  
Cherenkov Telescopes ◽  
Bl Lac ◽  
Γ Ray

ABSTRACT We present a search for high-energy γ-ray emission from 566 Active Galactic Nuclei at redshift z > 0.2, from the 2WHSP catalogue of high-synchrotron peaked BL Lac objects with 8 yr of Fermi-LAT data. We focus on a redshift range where electromagnetic cascade emission induced by ultra-high-energy cosmic rays can be distinguished from leptonic emission based on the spectral properties of the sources. Our analysis leads to the detection of 160 sources above ≈5σ (TS ≥25) in the 1–300 GeV energy range. By discriminating significant sources based on their γ-ray fluxes, variability properties, and photon index in the Fermi-LAT energy range, and modelling the expected hadronic signal in the TeV regime, we select a list of promising sources as potential candidate ultra-high-energy cosmic ray emitters for follow-up observations by Imaging Atmospheric Cherenkov Telescopes.

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