Search for isotropic γ radiation in the cosmological window between 65 and 200 TeV

Karle, A.; Martinez, S.; Plaga, R.; Arqueros, F.; Becker, K.-H.; Bradbury, S. M.; Fernández, J.; Fernández, P.; Fonseca, V.; Funk, Burkhardt; Haustein, V.; Heinzelmann, G.; Henke, V.; Krawczynski, H.; Krennrich, F.; Kuhn, Manuela; Lindner, A.; Lorenz, E.; Magnussen, N.; Matheis, V.; Merck, M.; Meyer, H.; Mirzoyan, R.; Müller, Norbert; Petry, D.; Prahl, J.; Prosch, C.; Renker, D.; Rhode, W.; Różańska, M.; Samorski, M.; Sander, H.; Schmele, D.; Sooth, R. N.; Stamm, W.; Westerhoff, S.; Wiebel-Sooth, B.; Willmer, M.

doi:10.1016/0370-2693(95)00132-5

Cited by 35 publications

(20 citation statements)

References 17 publications

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“…Earlier publications dealing with the HEGRA arrays address: a description of AIROBICC performance (Karle 1995a), the search for gamma-ray point sources using the first year of data of the detector, a data set not included in this analysis (Karle 1995b), a search for Gamma Ray Bursts (Padilla 1998), an analysis of the Chemical Composition of Very High Energy (VHE) Cosmic Rays (Arqueros 2000), and two studies of the diffuse VHE gamma ray background (Aharonian 2001;Karle 1995c).…”

Section: Introductionmentioning

confidence: 99%

Search for point sources of gamma radiation above 15 TeV with the HEGRA AIROBICC array

Aharonian

Akhperjanian

Barrio

et al. 2002

A&A

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Abstract.A search for potential point sources of very high energy gamma rays has been carried out on the data taken simultaneously by the HEGRA AIROBICC and Scintillator arrays from August 1994 to March 2000. The list of sought sources includes supernova remnants, pulsars, AGNs and binary systems. The energy threshold is around 15 TeV. For the Crab Nebula, a modest excess of 2.5 standard deviations above the cosmic ray background has been observed. Flux upper limits (at 90% c.l.) of around 1.3 times the flux of the Crab Nebula are obtained, in average, for the candidate sources. A different search procedure has been used for an all-sky search which yields absolute flux upper limits between 4 and 9 crabs depending on declination, in the band from δ = 0 to δ = 60 • .

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Section: Introductionmentioning

confidence: 99%

Search for point sources of gamma radiation above 15 TeV with the HEGRA AIROBICC array

Aharonian

Akhperjanian

Barrio

et al. 2002

A&A

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“…The electrons and photons initiate electromagnetic cascades in the extragalactic radiation fields and magnetic field, resulting in a complicated spectrum of electrons and photons which is very sensitive to the radiation and magnetic environment. For example, recently the HEGRA group [14] have placed an upper limit on the ratio of g rays to cosmic rays of ϳ10 22 at 10 5 GeV and, using a TD model calculation [7] which neglected the IR background and gave a higher ratio, argued that TD models were ruled out. However, inclusion of the IR would reduce the 10 5 GeV g-ray intensity to well below the HEGRA limit.…”

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confidence: 99%

Limits on Models of the Ultrahigh Energy Cosmic Rays Based on Topological Defects

1996

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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%

“…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]. The EASTOP collaboration had also probed the diffuse UHE γ-rays above 870 TeV using the muonpoor criterion [30].…”

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

confidence: 98%

“…The HEGRA collaboration had used the HEGRA EAS array in association with the AIROBICC array of atmospheric erenkov detectors to probe the diffuse γ-ray flux in the energy region 65-200 TeV. They had placed a limit of 10 -2 at 65 TeV on the ratio of the flux of γs to charged cosmic rays [28]. This upper limit at the time was a factor of 4 lower than the predicted ratio for one of the topological defect models [27].…”

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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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Search for isotropic γ radiation in the cosmological window between 65 and 200 TeV

Cited by 35 publications

References 17 publications

Search for point sources of gamma radiation above 15 TeV with the HEGRA AIROBICC array

Search for point sources of gamma radiation above 15 TeV with the HEGRA AIROBICC array

Limits on Models of the Ultrahigh Energy Cosmic Rays Based on Topological Defects

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

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