PeVatrons are natural particle accelerators that can accelerate particles with energies
of up to 1 PeV. Although the term PeVatron was coined by the High Energy Stereoscopic
System (HESS) collaboration in 2016 through the analysis of the galactic centre, its era
began in 2021 thanks to the discovery of ultra-high-energy gamma-ray sources by highly
sensitive observatories such as the High Altitude Water Cherenkov (HAWC) Observatory in
Mexico, the Tibet AS-gamma Experiment in Tibet (led by the University of Tokyo, Japan)
and the Large High Altitude Air Shower Observatory (LHAASO-LHAASO-KM2A). In this seminar
I will give a brief overview of the PeVatrons and explain why the analysis of molecular
observations in combination with X-rays is essential for their study and in this context
represents a turning point in contemporary astronomy.