Measuring Large-Scale Anisotropy in the Arrival Directions of Cosmic Rays Detected at the Telescope Array and the Pierre Auger Observatory above 10 EeV

THE PIERRE AUGER COLLABORATION (AUTOR 434 DE 474); M. TUEROS

Rio de Janeiro

Conferencia; 33rd International Cosmic Ray Conference (ICRC 2013); 2013

International Union of Pure and Applied Physics (IUPAP)

Abstract: Spherical harmonic moments are well-suited for characterizing anisotropy in the flux of cosmic rays.So far, above 1019 eV, no study has revealed a significant departure from isotropy. The dipole vector and thequadrupole tensor are of special interest, and access to the full set of multipoles could provide essential informa-tion for understanding the origin of ultra-high energy cosmic rays. Full-sky coverage allows the measurement ofthe spherical harmonic coefficients in an unambiguous way. This can be achieved by combining data from ob-servatories located in both the northern and southern hemispheres. In this work, we present the prospects for acombined analysis using data recorded at the Telescope Array and the Pierre Auger Observatory. The main chal-lenges are to account adequately for the relative exposures of both experiments and possibly different absoluteenergy normalizations. Using Monte-Carlo simulations, we show how these challenges will be addressed in anempirical way and illustrate the expected sensitivity of the methodology for the present observatory exposures.Keywords: Telescope Array, Pierre Auger Observatory, Ultra-High Energy Cosmic Rays, Large-ScaleAnisotropies, Full-Sky Coverage.