An ominous looking galactic scale of gases appears to have hit the Milky Way.
According to Phys.org, “Astronomers at Harvard University have discovered a monolithic, wave-shaped gaseous structure—the largest ever seen in our galaxy—made up of interconnected stellar nurseries. Dubbed the ‘Radcliffe wave’ in honor of the collaboration’s home base, the Radcliffe Institute for Advanced Study, the discovery transforms a 150-year-old vision of nearby stellar nurseries as an expanding ring into one featuring an undulating, star-forming filament that reaches trillions of miles above and below the galactic disk.”
The wave was first revealed in a study in the journal Nature.
Phys.org says, “The researchers discovered a long, thin structure, about 9,000 light years long and 400 light years wide, with a wave-like shape, cresting 500 light years above and below the mid-plane of our Galaxy’s disk. The Wave includes many of the stellar nurseries that were previously thought to form part of “Gould’s Belt“, a band of star-forming regions believed to be oriented around the Sun in a ring. “No astronomer expected that we live next to a giant, wave-like collection of gas—or that it forms the Local Arm of the Milky Way,” said Alyssa Goodman, the Robert Wheeler Willson Professor of Applied Astronomy at Harvard University, research associate at the Smithsonian Institution, and co-director of the Science Program at the Radcliffe Institute of Advanced Study. “We were completely shocked when we first realized how long and straight the Radcliffe Wave is, looking down on it from above in 3-D—but how sinusoidal it is when viewed from Earth. The Wave’s very existence is forcing us to rethink our understanding of the Milky Way’s 3-D structure.”
The Sun lies only 500 light years from the Wave at its closest point. It’s been right in front of our eyes all the time, but we couldn’t see it until now. “We suspected there might be larger structures that we just couldn’t put in context. So, to create an accurate map of our solar neighborhood, we combined observations from space telescopes like Gaia with astrostatistics, data visualization, and numerical simulations.” explained Zucker, who is an NSF Graduate Fellow and Ph.D. candidate at Harvard’s Graduate School of Arts and Sciences based in Harvard’s department of Astronomy. Harvard graduate students Catherine Zucker and Joshua Speagle recently augmented these techniques, dramatically improving the ability of astronomers to measure distances to star-forming regions. That work, led by Zucker, is published in the Astrophysical Journal.