You may not realize it in your day-to-day life, but we are all enveloped by a giant “superbubble” that was blown into space by the explosive deaths of a dozen-odd stars. Known as the Local Bubble, this structure extends for about 1,000 light years around the solar system, and is one of countless similar bubbles in our galaxy that are produced by the fallout of supernovas. Cosmic superbubbles have remained fairly mysterious for decades, but recent astronomical advances have finally exposed key details about their evolution and structure. Just within the past few years, researchers have mapped the geometry of the Local Bubble in three dimensions and demonstrated that its surface is an active site of star birth, because it captures gas and dust as it expands into space.
Now, a team of scientists has added another layer to our evolving picture of the Local Bubble by charting the magnetic field of the structure, which is thought to play a major role in star formation. Astronomers led by Theo O’Neill, who conducted the new research during a summer research program at the Center for Astrophysics at Harvard & Smithsonian (CfA), presented “the first-ever 3D map of a magnetic field over a superbubble” on Wednesday at the American Astronomical Society’s 241st annual meeting in Seattle, Washington. The team also unveiled detailed visualizations of their new map, bringing the Local Bubble into sharper focus.
“We think that the entire interstellar medium is really full of all these bubbles that are driven by various forms of feedback from, especially, really massive stars, where they’re outputting energy in some form or another into the space between the stars,” said O’Neill, who just received an undergraduate degree in astronomy-physics and statistics from the University of Virginia, in a joint call with their mentor Alyssa Goodman, an astronomer at CfA who co-authored the new research. […] “Now that we have this map, there’s a lot of cool science that can be done both by us, but hopefully by other people as well,” O’Neill said. “Since stars are clustered, it’s not as if the Sun is super special, and is in the Local Bubble because we’re just lucky. We know that the interstellar medium is full of bubbles like this, and there’s actually a lot of them nearby our own Local Bubble.” “One cool next step will be looking at places where the Local Bubble is nearby other feedback bubbles,” they concluded. “What happens when these bubbles interact, and how does that drive start formation in general, and the overall long-term evolution of galactic structures?”