Towards gamma-ray astronomy with timing arrays

The gamma-ray energy regime beyond 10 TeV is crucial for the search for the most energetic Galactic accelerators. The energy spectra of most known gamma-ray emitters only reach up to few 10s of TeV, with 80 TeV from the Crab Nebula being the highest energy so far observed significantly. Uncovering their spectral shape up to few 100 TeV could answer the question whether some of these objects are cosmic ray Pevatrons, i.e. Galactic PeV accelerators.Sensitive observations in this energy range and beyond require very large effective detector areas of several 10s to 100 square-km. While imaging air Cherenkov telescopes have proven to be the instruments of choice in the GeV to TeV energy range, very large area telescope arrays are limited by the number of required readout channels per instrumented square-km (due to the large number of channels per telescope). Alternatively, the shower-front sampling technique allows to instrument large effective areas and also naturally provides large viewing angles of the instrument. Solely measuring the shower front light density and timing (hence timing- arrays), the primary particle properties are reconstructed on the basis of the measured lateral density function and the shower front arrival times. This presentation gives an overview of the technique, its goals, and future perspective

Towards gamma-ray astronomy with timing arrays

The gamma-ray energy regime beyond 10 TeV is crucial for the search for the most energetic Galactic accelerators. The energy spectra of most known gamma-ray emitters only reach up to few 10s of TeV, with 80 TeV from the Crab Nebula being the highest energy so far observed significantly. Uncovering their spectral shape up to few 100 TeV could answer the question whether some of these objects are cosmic ray Pevatrons, i.e. Galactic PeV accelerators.Sensitive observations in this energy range and beyond require very large effective detector areas of several 10s to 100 square-km. While imaging air Cherenkov telescopes have proven to be the instruments of choice in the GeV to TeV energy range, very large area telescope arrays are limited by the number of required readout channels per instrumented square-km (due to the large number of channels per telescope). Alternatively, the shower-front sampling technique allows to instrument large effective areas and also naturally provides large viewing angles of the instrument. Solely measuring the shower front light density and timing (hence timing- arrays), the primary particle properties are reconstructed on the basis of the measured lateral density function and the shower front arrival times. This presentation gives an overview of the technique, its goals, and future perspective

Simulation of the hybrid Tunka Advanced International Gamma-ray and Cosmic ray Astrophysics (TAIGA)

Up to several 10s of TeV, Imaging Air Cherenkov Telescopes (IACTs) have proven to be the instruments of choice for GeV/TeV gamma-ray astronomy due to their good reconstrucion quality and gamma-hadron separation power. However, sensitive observations at and above 100 TeV require very large effective areas (10 km(2) and more), which is difficult and expensive to achieve.The alternative to IACTs are shower front sampling arrays (non-imaging technique or timing-arrays) with a large area and a wide field of view. Such experiments provide good core position, energy and angular resolution, but only poor gamma-hadron separation. Combining both experimental approaches, using the strengths of both techniques, could optimize the sensitivity to the highest energies.The TAIGA project plans to combine the non-imaging HiSCORE [8] array with small (∼10m(2)) imaging telescopes. This paper covers simulation results of this hybrid approach