Observation of the anisotropy in arrival direction of Cosmic Rays with IceCube

TL;DR

This paper reports the detection of anisotropy in cosmic ray arrival directions using IceCube, revealing large-scale and medium-scale structures consistent with previous observations and providing new insights into cosmic ray propagation.

Contribution

First observation of cosmic ray anisotropy at IceCube, extending understanding of cosmic ray distribution across different angular scales.

Findings

Detection of large-scale anisotropy consistent with Northern Hemisphere observations

Identification of medium-scale features potentially linked to larger structures

Cosmic rays have a non-uniform arrival direction distribution

Abstract

The IceCube Neutrino Observatory is a kilometer-scale detector currently under construction at the South Pole. In its final configuration the detector will comprise 5160 Digital Optical Modules (DOMs) deployed on 86 strings between 1.5-2.5 km deep within the ice. While still incomplete, the detector has already recorded tens of billions of cosmic ray muons with a median energy of 20 TeV. This large sample has been used to study the arrival direction distribution of the cosmic rays. We report the observation of an anisotropy in the cosmic rays arrival direction at two different angular scales. The observed large scale anisotropy seems to be a continuation of similar structures observed in the Northern Sky by several experiments. IceCube observes also significant features on the angular scale of $20^{\circ} - 30^{\circ}$ that might be part of the larger scale structure.