# gst astro: when a superbubble can generate trains of shock waves

<< Sixty-seven million light-years away, a galaxy is blowing enormous bubbles. We know what they are. Known as nuclear superbubbles, the structures are likely created by the supermassive black hole in the galaxy's centre. Now, thanks to new data, we know something incredible is occurring inside them. >>

<< Observations from NASA's Chandra X-ray Observatory of spiral galaxy NGC 3079 have revealed that the bubbles are actually a huge cosmic particle accelerator, producing energetic high-speed particles around their edges.  >>

<< As the bubbles expand into the surrounding gas of the interstellar medium, they generate shock waves, which in turn produce tangled magnetic fields. (..)  particles ricochet around these shock magnetic fields; when they pass through the shock front, they get an acceleration boost.  >>

Michelle Starr. Astronomers Have Found 'Superbubbles' Producing Shock Waves in Another Galaxy.  Mar 4, 2019.

https://www.sciencealert.com/colossal-bubbles-blown-by-a-supermassive-black-hole-are-a-cosmic-particle-accelerator

Jiang-Tao Li, Edmund Hodges-Kluck, et al. Detection of non-thermal hard X-ray emission from the "Fermi bubble" in an external galaxy.  ApJ in press. arXiv:1901.10536v1 [astro-ph.HE] Jan 31, 2019.

https://arxiv.org/abs/1901.10536