Anisotropy of Galactic Cosmic Rays and New Discoveries in Its Measurements

TL;DR

This paper critiques recent two-dimensional measurements of cosmic ray anisotropy in the 1-100 TeV range, arguing they do not provide new insights and are based on misleading interpretations of the data.

Contribution

It clarifies that 2D measurements do not reveal the true anisotropy direction and challenges the validity of recent interpretations based on these measurements.

Findings

2D measurements do not provide new anisotropy information

The phase remains the only directly measured parameter

Interpretations based on 2D maps are invalid

Abstract

We discuss recently published results of two-dimensional measurements of the cosmic ray anisotropy in the energy range 1-100 TeV. It is demonstrated that, in spite of pretence of the authors to measure the anisotropy in more detail than it was done in one-dimensional measurements of the first harmonic of CR intensity in sidereal time, new measurements give nothing essentially new. Moreover, two-dimensional picture is misleading creating an illusion that the true direction of the anisotropy is observed, while, as before, only the projection of the anisotropy onto the equatorial plane is measured and the phase of the anisotropy remains to be the only directly measured parameter. The sophisticated interpretations of the results of 2D measurements made by their authors are invalid, since they are based on the false assumption that the equatorial excess and deficit of CR intensity seen on the difference maps represent the real anisotropy.