gamma-ray emission from LS I +61 303: The impact of basic system uncertainties

TL;DR

This paper investigates how uncertainties in the orbital parameters and stellar wind assumptions of LS I +61 303 affect gamma-ray emission predictions, comparing model results with MAGIC telescope observations.

Contribution

It highlights the significance of system uncertainties in modeling gamma-ray emission and assesses their impact on observational predictions.

Findings

Uncertainties significantly influence gamma-ray opacity calculations.

Geometry affects gamma-ray propagation and escape.

Model comparisons with MAGIC data provide insights into system parameters.

Abstract

LS I +61 303 has been recently detected as a periodic gamma-ray source by the Major Atmospheric Imaging Cerenkov (MAGIC) telescope. A distinctive orbital correlation of the $\gamma$-ray emission was found. This work shows that the range of uncertainties yet at hand in the orbital elements of the binary system LSI as well as in the possible assumptions on the stellar wind of the optical companion play a non-negligible role in the computation of opacities to high energy processes leading to $\gamma$-ray predictions. The geometry influence on the propagation and escape of $\gamma$-ray photons is explored. With this study at hand, we analyse the results of a pulsar wind zone model for the production of gamma-rays and compare it with recent MAGIC observations.