Using spherical wavelets to search for magnetically-induced alignment in the arrival directions of ultra-high energy cosmic rays

TL;DR

This paper introduces a novel spherical wavelet-based method to detect filamentary multiplet structures in the arrival directions of ultra-high energy cosmic rays, aiding the search for magnetic field effects.

Contribution

It presents a new wavelet transform technique for identifying multiplets in cosmic ray sky maps, improving detection of magnetic deflections.

Findings

Effective detection of multiplets in simulated data

Assessment of algorithm's error rates

Potential application in cosmic ray anisotropy studies

Abstract

Due to the action of the intervening cosmic magnetic fields, ultra-high energy cosmic rays (UHECRs) can be deflected in such a way as to create clustered energy-ordered filamentary structures in the arrival direction of these particles, the so-called multiplets. In this work we propose a new method based on the spherical wavelet transform to identify multiplets in sky maps containing arrival directions of UHECRs. The method is illustrated in simulations with a multiplet embedded in isotropic backgrounds with different numbers of events. The efficiency of the algorithm is assessed through the calculation of Type I and II errors.