Pre-submission Thesis Presentation

Space-based and ground-based observational experiments have revolutionized the field of multi-messenger and multi-wavelength astrophysics. As a result, many previously unexplored high-energy astrophysical phenomena have been unveiled for us to decipher. One such example is the “positron excess” anomaly observed by AMS-02 and PAMELA, the origin of which is still debatable. I will discuss our model, which describes the positron excess while being consistent with the other cosmic ray observables. Many point-like and extended unidentified gamma-ray sources have been observed in the Galaxy by current-generation Imaging Atmospheric Cherenkov Telescopes such as HESS, MAGIC, etc. Detailed multi-wavelength study and further theoretical modeling can help confirm the nature of the underlying Galactic sources responsible for the observed emission. Furthermore, air shower arrays such as LHAASO have observed more than a dozen ultra-high energy gamma-ray sources associated with “PeVatron” accelerators in the Galaxy, the nature of which is not adequately understood. I will present a multi-wavelength study of an unidentified HESS source labeled HESS J1828-099, which we identify as a gamma-ray binary. I will also discuss the emission mechanism behind two of the observed PeVatrons, LHAASO J1908+0621, and LHAASO J2226+6057.