Gamma Rays from Massive Stars
This image shows the star-forming region RCW 38, which is located
5,500 light-years from Earth. At less than a million years old — and
possibly as young as 100,000 years — RCW 38 is the youngest super star
cluster in the Milky Way. In the image above, infrared light from the
Spitzer Space Telescope is shown in red, X-rays from the Chandra X-ray
Observatory are in green, and gamma rays from the Fermi Gamma-ray Space
Telescope are in blue. Paarmita Pandey (The Ohio State University) and
coauthors recently observed this cluster in order to test the hypothesis
that the outflowing winds of massive stars are a source of cosmic rays:
charged particles traveling near the speed of light. Cosmic rays might
be generated when winds from several stars crash into one another or
into the gas of the interstellar medium. Pandey’s team hoped to find
evidence for this process in the form of gamma rays, which are produced
when cosmic rays collide with other particles. Using data from Fermi,
the team found clear evidence of gamma rays coming from the region,
adding to the small but growing number of young star clusters that are
known to be associated with gamma-ray production. To learn more about
this work, be sure to check out the full study linked below.
Citation
“Constraining the Diffusion Coefficient and Cosmic-Ray Acceleration
Efficiency Using Gamma-Ray Emission from the Star-Forming Region RCW
38,” Paarmita Pandey et al 2024 ApJ 976 98. doi:10.3847/1538-4357/ad83bc
