Can star clusters accelerate particles faster than supernovas?

Infrared map
Infrared map from the Cocoon region overlaid with gamma-ray significance map from HAWC. (Image: TeV: Binita Hona (HAWC Collaboration), IR: Hora et. al, Spitzer’s Growing Legacy, ASP Conference Series, 2010, P. Ogle, ed.)

New insights into how cosmic rays are formed

An international team of researchers has now demonstrated for the first time that high-energy cosmic rays are formed in the area surrounding massive stars. Their observations provide new insights into how cosmic rays are formed and develop. The results of this research, in which an astrophysicist from FAU was involved, have now been published in the renowned journal Nature Astronomy.

The High-Altitude Water Cherenkov (HAWC) observatory in Mexico has detected cosmic gamma rays with energies of up to 200 teraelectronvolts from the direction of the ‘Cygnus Cocoon’. This is a superbubble that surrounds the birthplace of massive stars. Analyses have shown that these gamma rays could be generated by cosmic rays in the petaelectronvolt range.

The cosmic ray particles are accelerated to petaelectronvolt energies in the star-forming region within the cocoon. These cosmic rays interact with the gas in the region, thus generating the observed gamma rays.

The distribution of energy and the location of the gamma rays in the cocoon vary with giga and teralectronvolt energies, which suggests that the particles in the cocoon are transported differently at varying energies.

These findings provide new insights into the formation and development of cosmic rays and about earlier activity in the superbubble. They also show for the first time that cosmic rays in the petaelectronvolt range are generated in the area surrounding massive stars.

Further information

A detailed press release can be found on the Michigan Techological University website.

DOI: 10.1038/s41550-021-01318-y

Dr. Vikas Joshi
Chair of Physics
Phone: 09131/85-27093