Ultrahigh energy gamma-ray sources and their multimessenger connections

Abstract: 

The detection of multiple TeV–PeV gamma-ray sources in our Galaxy by the Large High Altitude Air Shower Observatory (LHAASO) has opened new opportunities to study the nature of Galactic PeVatrons. Several of these ultra-high-energy gamma-ray–emitting regions are spatially coincident with pulsar wind nebulae (PWNe). These observations provide direct evidence that electrons can be accelerated to PeV energies in pulsar environments. Furthermore, multiwavelength observations of these sources are crucial for constraining the particle injection spectra, diffusion properties, and magnetic field strengths within the nebulae. In addition, supernova remnants, microquasars, and young massive stellar clusters have been observed as sources of ultra-high-energy gamma rays.

In this talk, I will discuss the ultra-high-energy gamma-ray sources identified in recent years. I will also discuss our recent progress in identifying giant molecular clouds as potential multimessenger sources.