Fermi Spots Star Cluster Blowing Gamma-Ray Bubbles
This artist’s concept shows the location of Westerlund 1 relative to our Sun as seen from the underside of our Milky Way galaxy. The magenta bubble illustrates what the nascent outflow might look like in gamma rays. Credit: NASA’s Goddard Space Flight Center/Conceptual Image Lab
For the first time, astronomers using NASA’s Fermi telescope have traced a budding outflow of gas from a cluster of young stars in our galaxy.
The cluster, called Westerlund 1, is located about 12,000 light-years away in the southern constellation Ara. It’s the closest, most massive, and most luminous super star cluster in the Milky Way.
Scientists looked back through nearly two decades of Fermi observations of Westerlund 1. Fermi’s sensitivity and resolution helped them filter out other sources like rapidly spinning stellar remnants called pulsars.
They discovered a bubble of gamma rays extending over 650 light-years from the cluster below the plane of the Milky Way.
The researchers call this a nascent, or early stage, outflow because it was likely recently produced by massive young stars within the cluster and hasn’t yet had time to break out of the galactic disk. Eventually it will stream into the galactic halo, the hot gas surrounding the Milky Way.
More About Fermi
The same detectors that enable Fermi's detailed measurements of distant cosmic objects have also become key to imaging, monitoring, and non-proliferation of nuclear materials here on Earth.
Technology for future gamma-ray missions is further advancing radiation detectors for use with drones and for unattended monitoring.
Fermi is a key part of NASA's contributions to multimessenger astronomy, which is how scientists explore the cosmos using light, particles, and gravitational waves.
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NASA’s Fermi Spots Young Star Cluster Blowing Gamma-Ray Bubbles
