Observation of Cosmic Ray Anisotropy with Nine Years of IceCube Data

Frank McNally, Rasha Abbasi, Paolo Desiati, Juan Carlos Díaz Vélez, Timothy Aguado, Katherine Gruchot, Andrew Moy, Alexander Simmons, Andrew Thorpe, Hannah Woodward

Published 2021-07-23Version 1

The IceCube Observatory has collected over 577 billion cosmic-ray induced muon events in its final configuration from May 2011 to May 2020. We used this data set to provide an unprecedented statistically accurate map of the cosmic ray arrival direction distribution in the TeV-PeV energy range scale in the Southern Hemisphere. Such an increase in event statistics makes it possible to extend the sensitivity to anisotropies at higher cosmic ray energies and smaller angular scales. It will also facilitate a more detailed assessment of the observatory stability over both short- and long-time scales. This will enable us to study the time variability of the cosmic ray anisotropy on a yearly-base and over the entire data sample period covering most of the solar cycle 24. We present the preliminary results from the study with the extended event sample.