An improved method to search for flares from point sources of ultra-high-energy photons

Flares produced by certain classes of astrophysical objects may be sources of some ultra-high-energy particles, which, if they are photons, would group into clusters of events correlated in space and time. Identification of such clustering in cosmic-ray data would provide important evidence for poss...

Full description

Saved in:
Bibliographic Details
Published in:arXiv.org 2024-12
Main Authors: Stasielak, J, Borodai, N, Góra, D, Niechciol, M
Format: Article
Language:English
Subjects:
Algorithms
Clustering
Cosmic ray showers
Cosmic rays
Distribution functions
Flares
Hadrons
High energy astronomy
Photons
Probability distribution functions
Searching
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Flares produced by certain classes of astrophysical objects may be sources of some ultra-high-energy particles, which, if they are photons, would group into clusters of events correlated in space and time. Identification of such clustering in cosmic-ray data would provide important evidence for possible existence of ultra-high-energy (UHE) photons and could potentially help identify their sources. We present an analysis method to search for space-time clustering of ultra-high-energy extensive air showers, namely the stacking method, which combines a time-clustering algorithm with an unbinned likelihood study. In addition, to enhance the capability to discriminate between signal (photon-initiated events) and background (hadron-initiated) events, we apply a photon tag. This involves using relevant probability distribution functions to classify each event as more likely to be either a photon or a hadron. We demonstrate that the stacking method can effectively distinguish between events initiated by photons and those initiated by hadrons (background). The number of photon events in a data sample, as well as the flare(s) duration can also be retrieved correctly. The stacking method with a photon tag requires only a few events to identify a photon flare. This method can be used to search for the cosmic ray sources and/or improve limits on the fluxes of UHE photons.
ISSN:2331-8422