γ-ray emission from LS i +61 303: The impact of basic system uncertainties

LS I +61 303 has been recently detected as a periodic γ-ray source by the Major Atmospheric Imaging Cerenkov (MAGIC) telescope. A distinctive orbital correlation of the γ-ray emission was found. This work shows that the range of uncertainties yet at hand in the orbital elements of the binary system LS I +61 303 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 γ-ray predictions. The geometry influence on the propagation and escape of γ-ray photons is explored. With this study at hand, we analyze the results of a pulsar wind zone model for the production of γ-rays and compare it with recent MAGIC observations. © 2009. The American Astronomical Society. All rights reserved.