Search for diffuse cosmic gamma rays above 200 TeV

Matthews, J.; Ciampa, D.; Green, K. D.; Kolodziejczak, Jeffery J.; Nitz, D.; Sinclair, D.; Thornton, G.; Velde, J. C. van der; Cassiday, G. L.; Cooper, R.; Corbató, S. C.; Dawson, B. R.; Elbert, J. W.; Fick, B.; Kieda, D. B.; Ko, S.; Liebing, D. F.; Loh, E. C.; Salamon, M. H.; Smith, J. D.; Sokolsky, P.; Thomas, S. B.; Wheeler, B.

doi:10.1086/170181

Cited by 35 publications

(18 citation statements)

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“…GRAPES-3 upper limits are significantly more sensitive than the ones placed by the AIROBICC [28], Utah-Michigan [114], EASTOP [30], and CASA-MIA [31] experiments. In the important 50-200 TeV energy region the GRAPES-3 upper limits are about an order of magnitude smaller than the rest.…”

Section: S K Guptamentioning

confidence: 74%

“…Subsequently, other detections were also reported by the [112] and the Tien-Shan [113] experiments. The 864 S K Gupta CASA-MIA collaboration had reported an upper limit on the diffuse flux of UHE γ-rays [114]. Upper limits on the diffuse flux UHE γ-rays was also reported by the HEGRA collaboration in the energy region TeV, based on their study of the lateral distribution of the Cerenkov photons in the EAS [28].…”

Section: High Energy Astroparticle Physics At Ooty and The Grapes-3 Ementioning

confidence: 89%

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High Energy Astroparticle Physics at Ooty and the GRAPES-3 Experiment

Gupta¹

2014

Proceedings of the Indian National Science Academy

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The astroparticle studies at Ooty have their roots going way back into the fifties, when studies using cosmic rays were initiated with cloud chambers of progressively larger sizes as the primary detector and measuring device to obtain properties of hadrons at high energies. This study was subsequently strengthened with the installation of a total absorption calorimeter and a modest extensive air shower array to probe the composition of the primary cosmic rays to very high energies. The discovery of pulsars provided a thrust for the exploration of these compact objects as the sources of γ-rays at TeV energies with the aid of atmospheric Cerenkov detectors in the seventies. With the rapid technological advances occurring during the subsequent years in detectors, electronics and computers, physicists world-wide were able to set up very large and remarkably sensitive experiments that were hard to imagine a decade earlier. With the increasing sophistication and complexity the modern experiments require participation of very large teams of scientists. This development has made the formation of collaboration of large number of physicists both experimental and theoretical, engineers, technicians etc., from a number of institutions and universities, a prerequisite for setting up any major experimental facility. The GRAPES-3 experiment is a collaboration of 34 scientists from 13 institutions, including 8 from India and 5 from Japan. The GRAPES-3 experiment contains a dense extensive air shower array operating with ~ 400 scintillator detectors and a 560 m 2 tracking muon detector (Em > 1 GeV), at Ooty in India. 25 % of scintillator detectors are instrumented with two fast photomultiplier tubes (PMTs) for extending the dynamic range to ~ 5x10 3 particles m -2. The scintillators, signal processing electronics and data recording systems were fabricated in-house to cut costs and optimize performance. The muon multiplicity distribution of the EAS is used to probe the composition of primary cosmic rays below the 'knee', with an overlap with direct measurements. Search for multi-TeV γ-rays from point sources is done with the aid of the muon detector. A good angular resolution of 0.7 o at 30 TeV, is measured from shadow of the Moon on the isotropic flux of cosmic rays. Sensitive limit on the diffuse flux of 100 TeV γ-rays is placed by using muon detector to filter out the charged cosmic ray background. The tracking muon detector allows sensitive measurements on the coronal mass ejections and solar flares through Forbush decrease events. We have major expansion plans to enhance the sensitivity of the GRAPES-3 experiment in the areas listed above. PACS

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Section: S K Guptamentioning

confidence: 74%

Section: High Energy Astroparticle Physics At Ooty and The Grapes-3 Ementioning

confidence: 89%

High Energy Astroparticle Physics at Ooty and the GRAPES-3 Experiment

Gupta¹

2014

Proceedings of the Indian National Science Academy

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“…The upper limits reported in Fig. 2 are due to the HEGRA [21], Utah-Michigan [22], EASTOP [23] and CASA-MIA [24] experiments. The stronger constraints to the model of SH particles in the halo come from the CASA-MIA and EASTOP experiments: the calculated fluxes are compatible with the experimental limits with the exception of the case obtained for m X = 10 13 GeV and the SUSY-QCD fragmentation function.…”

Section: Discussionmentioning

confidence: 99%

“…All our fluxes are below this limit in the energy range accessible to current experiments. The points with arrows are the upper limits on the gamma ray flux from the HEGRA [21], Utah-Michigan [22], EAS-TOP [23] and CASA-MIA [24] experiments.…”

Section: A Detailed Calculationmentioning

confidence: 99%

Gamma rays from superheavy relic particles in the halo

Blasi

1999

Phys. Rev. D

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Superheavy (SH) quasistable particles generated in the Early Universe could be responsable for Ultra High Energy Cosmic Rays (UHECR) and be a component of Cold Dark Matter (CDM) in the universe. These particles are likely to cluster in the galactic halo, so that the main part of UHECR are gamma rays produced in the decay of neutral pions. Charged pions are also produced in the same process and result in high energy electrons. We consider here the production of gamma rays by synchrotron emission of these electrons in the galactic magnetic field. The gamma ray fluxes are in the region of interest for some current and proposed experiments (e.g. EGRET, GLAST, MILA-GRO) in the energy range 0.1 − 10 4 GeV. A comparison with the existing upper limits at 10 5 − 10 8 GeV is also carried out. The detection of this flux of gamma rays would be an important signature of SH relic particles as sources of UHECR and would give a clue to the physics of the Early Universe.

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“…where ǫ γ and ǫ p are the efficiencies for identifying γ-induced and protoninduced showers, respectively. Traditional extensive air-shower experiments have addressed γ/hadron-separation (i. e. background rejection) by identifying the penetrating particle component of air showers (see e. g. [14,15]), particularly muons. Although valid at energies exceeding 50 TeV, the number of muons detectable by a telescope of realistic effective area is small at TeV energies (see Figure 3 (a)).…”

mentioning

confidence: 99%

Conceptual design of a next-generation all-sky γ-ray telescope operating at TeV energies

Miller

Westerhoff

1999

Astroparticle Physics

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The next generation all-sky monitor operating at TeV (0.1 -30 TeV) energies should be capable of performing a continuous high sensitivity sky survey, and detecting transient sources, such as AGN flares, with high statistical significance on timescales of hours to days. We describe an instrument concept for a large area, wide aperture, TeV ground-based γ-ray telescope. The conceptual design is comprised of ∼ 20 000 1 m 2 scintillator-based pixels arranged in a densely packed mosaic. In addition to fast timing, the dense array of pixels also provides a unique imaging capability; the shower image, the spatial distribution of secondary particles at ground level, can be exploited to identify and reject hadronic backgrounds. The good angular resolution and background rejection capabilities lead directly to high sensitivity, while retaining a large field of view, large effective area, and high duty cycle. An instrument such as the one described here complements the narrow field of view air-Cherenkov telescopes and could, in conjunction with future space-based instruments, extend the energy range for continuous monitoring of the γ-ray sky from MeV through TeV energies.

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Search for diffuse cosmic gamma rays above 200 TeV

Cited by 35 publications

References 0 publications

High Energy Astroparticle Physics at Ooty and the GRAPES-3 Experiment

High Energy Astroparticle Physics at Ooty and the GRAPES-3 Experiment

Gamma rays from superheavy relic particles in the halo

Conceptual design of a next-generation all-sky γ-ray telescope operating at TeV energies

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