The constellation Cygnus, now visible in the western sky during twilight, hosts one of our galaxy's richest-known stellar construction zones. Astronomers viewing the region at visible wavelengths see only hints of this activity thanks to a veil of dust clouds forming "the Great Rift," a dark lane that splits the Milky Way.
Located in the vicinity of the second-magnitude star Gamma Cygni, the star-forming region was named Cygnus X when it was discovered as a diffuse radio source in the 1950s. Now, a study using data from NASA's Fermi Gamma-ray Space Telescope found that the tumult of star birth and death in Cygnus X has managed to corral fast-moving particles called cosmic rays.
Cosmic rays are subatomic particles (mostly protons) flying through the galaxy at nearly the speed of light, bouncing off electromagnetic fields in their path. However, when cosmic rays collide with interstellar gas, they produce gamma rays (the most energetic and penetrating form of light) that travel to us straight from the source. By tracing gamma-ray signals throughout the galaxy, Fermi's Large Area Telescope (LAT) is helping astronomers understand the sources of cosmic rays and how they're accelerated to such high speeds.
Cygnus X is estimated to have the raw materials to produce up to 2 million sun-like stars. This environment holds onto its cosmic rays despite their high energies by entangling them in turbulent magnetic fields created by the combined outflows of the region's numerous high-mass stars. This is providing astronomers with a new look at the early life of cosmic rays, before they long before they diffuse into the galaxy at large.
Bibliography:
www.sciencedaily.com
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