Gamma Emission from Large Galactic Structures

TL;DR

This paper discusses the use of gamma-ray observations to study cosmic ray propagation and origin in large galactic structures like molecular clouds and Fermi Bubbles, utilizing HAWC data.

Contribution

It presents preliminary results and upper limits on gamma-ray emission from molecular clouds and Fermi Bubbles using HAWC observations.

Findings

Upper limits set on gamma-ray flux from Fermi Bubbles

Preliminary detection efforts for gamma-ray emission from molecular clouds

Hawc's suitability for studying extended gamma-ray sources

Abstract

Gamma-ray emission from large structures is useful for tracing the propagation and distribution of cosmic rays throughout our Galaxy. For example, the search for gamma-ray emission from Giant Molecular Clouds may allow us to probe the flux of cosmic rays in distant galactic regions and to compare it with the flux measured at Earth. Also, the composition of the cosmic rays can be measured by separating the gamma-ray emission from hadronic or leptonic processes. In the case of emission from the Fermi Bubbles specifically, constraining the mechanism of gamma-ray production can point to their origin. HAWC possesses a large field of view and good sensitivity to spatially extended sources, which currently makes it the best suited ground-based observatory to detect extended regions. We will present preliminary results on the search of gamma-ray emission from Molecular Clouds, as well as upper limits on the differential flux from the Fermi Bubbles.