The dynamic range extension system for the LHAASO-WCDA experiment

2019

Phys. Rev. D

Recent detection of the neutrino event, IceCube-170922A by IceCube observatory from the Blazar TXS 0506+056 in the state of enhanced gamma ray emission indicates for acceleration of cosmic rays in the blazar jet. The non-detection of the broadline emission in the optical spectrum of TXS 0506+056 and other BL Lac objects suggests that external photons emissions are weak and hence photo-meson (pγ) interaction may not be a favored mechanism for high energy neutrino production. The lack of broadline signatures also creates doubt about the presence of a high density cloud in the vicinity of the super-massive black hole (SMBH) of TXS 0506+056 and consequently raised question on hadronuclear (pp) interaction interpretation like relativistic jet meets with high density cloud. Here we demonstrate that non-relativistic protons in the proton blazar model, those come into existence under charge neutrality condition of the blazar jet, offer sufficient target matter for pp−interaction with shock accelerated protons and consequently the model can describe consistently the observed high energy gamma rays and neutrino signal from the blazar TXS 0506+056.PACS numbers: 96.50.S-, 98.70.Rz, 98.70.Sa

Section: Numerical Results and Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Describing correlated observations of neutrinos and gamma-ray flares from the blazar TXS 0506+056 with a proton blazar model

Banik¹,

2019

Phys. Rev. D

“…Our findings suggest that the maximum energy of the cosmic ray particle achievable in the blazars is nearly 1 order less than the ankle energy of the cosmic ray energy spectrum in the observer frame and are required to explain consistently the observed gamma-ray and neutrino signal from the sources. The upcoming gamma-ray experiments like CTA [63] and LHAASO [64], which are very sensitive up to 100 TeV energies, may provide a clearer evidence of the physical origin of gamma-rays and maximum achievable energy of cosmic rays in AGN jets if more such events are detected from other blazars in upcoming years.…”

Section: Discussionmentioning

confidence: 99%

Implications of a proton blazar inspired model on correlated observations of neutrinos with gamma-ray flaring blazars

Banik¹,

Pandey

et al. 2020

Phys. Rev. D

Recent detection of the neutrino events IceCube-170922A, 13 muon-neutrino events observed in 2014-2015 and IceCube-141209A by IceCube observatory from the Blazars, namely TXS 0506+056, PKS 0502+049/TXS 0506+056 and GB6 J1040+0617 respectively in the state of enhanced gammaray emission, indicates the acceleration of cosmic rays in the blazar jets. The photo-meson (pγ) interaction cannot explain the IceCube observations of 13 neutrino events. The non-detection of broadline emission in the optical spectra of the IceCube blazars, however, question the hadronuclear (pp) interaction interpretation through relativistic jet meets with high density cloud. In this work, we investigate the proton blazar model in which the non-relativistic protons that come into existence under the charge neutrality condition of the blazar jet can offer sufficient target matter for pp interaction with shock-accelerated protons, to describe the observed high-energy gamma-rays and neutrino signal from the said blazars. Our findings suggest that the model can explain consistently the observed electromagnetic spectrum in combination with appropriate number of neutrino events from the corresponding blazars.PACS numbers: 96.50.S-, 98.70.Rz, 98.70.Sa

“…The full operations of the project is expected to be commenced by the middle of the next decade [58]. The Large High Altitude Air Shower Observatory (LHAASO) project is another most sensitive next generation instrument, to be built at 4410 meters of altitude in the Sichuan province of China [35,53]. The first phase of LHAASO will consist of a 1 km 2 array (LHAASO-KM2A) for electromagnetic particle detectors and an overlapping 1 km 2 array of 1146 underground water Cherenkov tanks 36 m 2 each in size for muon detection.…”

Section: Resultsmentioning

confidence: 99%

“…The LHAASO will be capable of continuously surveying the γ-ray sky for steady and transient sources from about 100 GeV to 1 PeV. The completion of the installation is expected by the end of 2021 [35,53].…”

Section: Resultsmentioning

confidence: 99%

Probing maximum energy of cosmic rays in SNR through gamma rays and neutrinos from the molecular clouds around SNR W28

Banik

2018

Astroparticle Physics

The galactic cosmic rays are generally believed to be originated in supernova remnants (SNRs), produced in diffusive shock acceleration (DSA) process in supernova blast waves driven by expanding SNRs. One of the key unsettled issue in SNR origin of cosmic ray model is the maximum attainable energy by a cosmic ray particle in the supernova shock. Recently it has been suggested that an amplification of effective magnetic field strength at the shock may take place in young SNRs due to growth of magnetic waves induced by accelerated cosmic rays and as a result the maximum energy achieved by cosmic rays in SNR may reach the knee energy instead of ∼ 200 TeV as predicted earlier under normal magnetic field situation. In the present work we investigate the implication of such maximum energy scenarios on TeV gamma rays and neutrino fluxes from the molecular clouds interacting with the SNR W28. The authors compute the gamma-ray and neutrino flux assuming two different values for the maximum energy reached by cosmic rays in the SNR, from CR interaction in nearby molecular clouds. Both protons and nuclei are considered as accelerated particles and as target material. Our findings suggest that the issue of the maximum energy of cosmic rays in SNRs can be observationally settled by the upcoming gammaray experiment the Large High Altitude Air Shower Observatory (LHAASO). The estimated neutrino fluxes from the molecular clouds are , however, out of reach of the present/near future generation of neutrino telescopes.