UHECRs in harmonic space

Discussion timeslot (ZOOM-Meeting): 16. July 2021 - 12:00
ZOOM-Meeting URL: https://desy.zoom.us/j/91896950007
ZOOM-Meeting ID: 91896950007
ZOOM-Meeting Passcode: ICRC2021
Corresponding Session: https://icrc2021-venue.desy.de/channel/28-Searches-for-Transients-MM/120
Live-Stream URL: https://icrc2021-venue.desy.de/livestream/Discussion-06/7

Abstract:
'I shall review our recent proposal of the use of the harmonic-space cross-correlation power spectrum between the arrival directions of ultra-high energy cosmic rays (UHECRs) and the distributions of galaxies in the Universe, as observed by cosmological surveys of the large-scale structure (LSS). We expect the two observables to correlate, due to both galaxies and UHECR sources being hosted within dark matter haloes, which constitute the very LSS. This cross-correlation has not yet been considered in the literature. We formalise analytically such a cross-correlation and show how, if the distribution of UHECR sources trace indeed the LSS, that the combination of auto- and cross-correlation greatly helps to detect UHECR anisotropies even with current data. We show that the cross-correlation is more sensitive to UHECR anisotropies on smaller angular scales, more robust to systematic uncertainties, and it could be used to determine the redshift distribution of UHECR source.'

Authors: Stefano Camera
Collaboration: Euclid Consortium, SKA Observatory.

Indico-ID: 1223
Proceeding URL: https://pos.sissa.it/395/980