Joint Likelihood Fits for the Study of Galactic Objects with HAWC

TL;DR

This paper discusses the use of joint likelihood fitting techniques to analyze gamma-ray data from the HAWC observatory, aiming to improve the study of Galactic objects despite challenges like source confusion and limited resolution.

Contribution

It introduces a systematic approach for joint likelihood fits to better interpret HAWC gamma-ray data and address issues like source confusion and morphological modeling.

Findings

Joint likelihood fits can mitigate source confusion effects.

Systematic uncertainties significantly impact measurement accuracy.

Method enhances the study of extended Galactic gamma-ray sources.

Abstract

Studying gamma-ray emission by Galactic objects is key to understanding the origins and acceleration mechanisms of Galactic cosmic ray electrons and hadrons. The HAWC observatory provides an unprecedented view of the gamma-ray sky at TeV energies and is particularly suited for the study of Galactic objects. However, the interpretation of the measured data poses several challenges. The high density of sources and source candidates can cause source confusion and make it harder to disentangle the origin of the emission. The relatively low angular resolution of HAWC, compared to instruments in optical or radio wavelengths, can further cause the emission of neighboring sources to bleed into each other or even make them look like one extended source. On the other hand, with its wide field of view, HAWC is uniquely suited for the study of extended sources. However, this requires the simultaneous modeling of both their morphology and emission spectrum. Joint likelihood fits to data taken over a larger range of energies can help overcome these challenges and achieve the full potential of the HAWC detector. In this presentation, we will discuss how systematic uncertainties related to joint likelihood fits can affect the measurements.