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Search for cosmic gamma rays of ultra-high energies with the Baksan air shower array. A.S. Lidvansky for the Carpet-3 Coll. Institute for Nuclear Research, Russian Academy of Sciences. The BASA: Scheme and view. Carpet-3 Project. Baksan river. Muon Detector 410 m 2.
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Search for cosmic gamma rays of ultra-high energies with the Baksan air shower array A.S. Lidvansky for the Carpet-3 Coll. Institute for Nuclear Research, Russian Academy of Sciences
Carpet-3Project Baksan river Muon Detector 410 m2 Additional 20 modules of surface detectors of 8.3 m2area (9 scintillation counters of area of 0.92 m2in each module)
IceCube results on detection of high-energy astrophysical neutrinos (Aartsen et al., 2013) stimulated experiments searching for 100 TeV diffuse gamma rays (produced in decays of neutral pions like neutrinos in charged) Several large-area muon detectors were planned and constructed for method of muon-poor showers (GRAPES-3, Tibet AS+MD, ALPACA, etc.). The Carpet-3 is one of such experiments. 4
Tibet AS + MD: “This is the first detection of photons with E > 100 TeV from an astrophysical source” [M. Amenomori et al. (Tibet ASγ Collaboration) First Detection of Photons with Energy beyond 100 TeV from an Astrophysical Source, Phys. Rev. Lett. 123, 051101 – Published 29 July 2019] ,
HAWC collaboration, “Measurement of the Crab Nebula at the Highest Energies with HAWC”, arXiv.org/abs/1905.12518 HAWC: 29 May 2019 15:17:06 UTC Tibet AS + MD: 13 Jun 2019 07:40:01 UTC
Cygnus X-3 campaign in UHE gamma ray astronomy in 1980s There were: One obviously wrong (as it became clear much later) publication of Kiel University group; A deluge of experimental and theoretical works; A specially constructed EAS array called Cygnus; A hypothetical new elementary particle cygnet; And many other experimental efforts and witty hypotheses.
BASA results on DC signal from Cyg X-3 Two spectral indices (2.1 and 2.7) were used and MWB absorption taken into account. Other experimental data: VHE (Cherenkov), Plateau Rosa, Kiel, and Haverah Park.
Burst of Cyg X-3 on October 14-16, 1985 X-ray image (Chandra, 1999) V.V. Alexeenko, A.E. Chudakov, Ya.S. Elensky, N.S. Khaerdinov,A.S. Lidvansky, N.I. Metlinsky, S.Kh. Ozrokov, V.V. Sklayrov,V.A. Tizengauzen, G. Navarra, Cygnus X-3 Observation in Gamma-Ray Energy Range 1014 eV. Il Nuovo Cimento, 10C, 151-161 (1987).
Burst of Cyg X-3 in October 1985 Gulmarg gamma ray telescope in India detected significant signals from Cyg X-3 on two days October 10 and 12 A model that exlained different delays of signals in this event: V.S. Berezinsky, Time delay of the PeV gamma ray burst after the October 1985 radio flare of Cygnus X-3, Nature, 1988, vol. 334, pp. 506-507.
The Crab Nebula burst on Feb 23, 1989 V.V. Alexeenko, A.S. Lidvansky, V.A. Tizengauzen, A Search for > 1014 eV Gamma Rays from Point Sources at Baksan Air Shower Array, Proceed. of Intern. Workshop on Very High Energy Gamma Ray Astronomy, Crimea, 1989, ed. by A.A.Stepanyan, D.J.Fegan, and M.F.Cawley, p. 137 • Acharya B.S., Rao M.V.S., Sivaprasad K., Sreekantan B.V., and Vishwanath P.R., First simultaneous detection of PeV energy burst from the Crab Nebula, Nature, 347(1990),364-5. • V.V. Alexeenko, Yu.M. Andreyev, A.E. Chudakov, Ya.S. Elensky,A.S. Lidvansky, S.Kh. Ozrokov, Yu.V. Stenkin, V.A. Tizengauzen,L.J. Graham, J.L. Osborne, A.W. Wolfendale. The ultra-high energygamma-ray burst from the Crab Nebula observed by the Baksan EASarray. Journ. of Phys. G : Nucl. Part. Phys. 18 (1992) L83-L88. With different significance the burst was detected by: KGF (India), Tien Shan (USSR), Baksan (USSR), EAS-TOP (Italy)
Time dependence of the counting rate in the source cell with a radius of 2.5 Phase analysis with period of pulsar PSR0531 (without absolute time reference)
Carpet-3 sensitivity to the flux of diffuse cosmic gamma rays
Two successive years the floods of the river Baksan damaged the array. Repairing works delayed realization of plans. Not all of surface detectors are installed at the moment. But MD starts operating with increased area.
Conclusions • Large-area muon detectors are a popular trend in modern UHE gamma ray astronomy • Some new results on recording UHE gammas from an astrophysical source (Crab) look quite impressive, but no more than very old ones • Amazingly, the random probabilities for burst-like events recorded decades ago are lower than in modern DC measurements • The Carpet-3 project is ready to start operating with 410 m2 MD