Search for gamma-ray sources in the LAT sky with the Minimal Spanning Tree algorithm

TL;DR

This paper introduces a topometric Minimal Spanning Tree method for detecting gamma-ray sources in the LAT sky, especially effective at higher energies and in less dense fields, improving cluster identification and source localization.

Contribution

The paper presents a novel MST-based clustering technique tailored for gamma-ray source detection in LAT data, with enhanced selection and coordinate estimation methods.

Findings

Effective in non-dense fields at energies above a few GeV

Improved cluster selection criteria

Simulation-based confidence level evaluation

Abstract

We present the topometric MST method to search for clusters of photons in the LAT sky, which was used to obtain the seed list for the compilation of the First LAT catalog. This method works well in non-dense field and can be profitably used at energies higher than a few GeV. We describe the particular techniques developed by us to improve the cluster selection criteria and the estimate of the astronomical coordinates of the possibly associated gamma-ray sources. A simulation technique to evaluate the confidence level of the source detectionis presented.