In the realm of astrophysics and energy research, a recent study has shed light on the origins of high-energy gamma-ray emissions surrounding the Westerlund 1 (Wd 1) star cluster. This research, conducted by Zhaodong Shi and Rui-zhi Yang from the Chinese Academy of Sciences, delves into the mechanisms behind these energetic phenomena, offering insights that could have implications for our understanding of cosmic rays and their interactions with interstellar matter.
Westerlund 1 is the most massive young star cluster known in our galaxy, and it has been observed that an extended gamma-ray source, HESS J1646-458, surrounds it. This gamma-ray emission extends up to an astonishing 80 TeV, indicating that cosmic rays (CRs) are being accelerated to extremely high energies in this region. However, the exact process responsible for this gamma-ray emission has remained unclear until now.
Shi and Yang have developed a model that explains the acceleration of cosmic rays at the termination shock within a superbubble. This superbubble is formed by the interaction of the cluster wind from Westerlund 1 with the surrounding interstellar medium. Their model focuses on the inelastic collisions of hadronic cosmic rays with the ambient gas, which produce gamma rays. By calculating the flux and radial profile of these gamma rays, the researchers have been able to match the observed spectrum and radial profile of the gamma-ray emission from HESS J1646-458.
The findings suggest that the gamma-ray emission is likely of hadronic origin, meaning it arises from the interactions of high-energy protons and atomic nuclei with the interstellar gas. This research provides a robust explanation for the observed gamma-ray emissions and offers a deeper understanding of the processes occurring in such extreme environments.
For the energy sector, this research highlights the powerful acceleration mechanisms at work in stellar clusters, which could inform studies on cosmic rays and their potential impacts on space-based energy infrastructure. Understanding these processes can also contribute to the development of advanced radiation shielding technologies and the design of more resilient space missions.
The study, titled “On the hadronic origin of the very high energy γ-ray emission surrounding the young massive stellar cluster Westerlund 1,” was published in the journal Physical Review D. This research not only advances our knowledge of astrophysical phenomena but also has practical implications for the energy industry, particularly in the realm of space-based energy systems and radiation protection.
This article is based on research available at arXiv.