All-Sky Cosmic-Ray Anisotropy Update at Multiple Energies

TL;DR

This paper updates the full-sky analysis of cosmic-ray anisotropy across multiple energies using data from HAWC and IceCube, confirming energy-dependent anisotropy and providing comprehensive sky coverage.

Contribution

It combines 8 years of HAWC data with 12 years of IceCube data to produce an extensive, bias-reduced all-sky map of cosmic-ray anisotropy across a broad energy range.

Findings

Confirms energy-dependent anisotropy in cosmic-ray arrival directions.

Provides 93% sky coverage, reducing biases from partial observations.

Extends analysis to higher energies up to 1 PeV.

Abstract

We present preliminary results on an updated full-sky analysis of the cosmic-ray arrival direction distribution with data collected by the High-Altitude Water Cherenkov (HAWC) Observatory and IceCube Neutrino Observatory with complementary field of views covering a large fraction of the sky. This study extends the energy range to higher energies. The HAWC Observatory, located at 19$^{\circ}$N has analyzed 8 years of cosmic-ray data over an energy range between 3.0 TeV and 1.0 PeV and confirms an energy-dependent anisotropy in the arrival direction distribution of cosmic rays seen by other experiments. Combined with recently published results from IceCube with 12 years of data, the combined sky maps with 93\% coverage of the sky -- between 70$^{\circ}$N and 90$^{\circ}$S -- and the corresponding angular power spectra largely eliminate biases that result from partial sky coverage.