In the vast distances between galaxies, space is not completely empty — gas and dust is blown into the void and this matter eventually becomes the seed for new stars and galaxies. But where does this matter come from? A new study reveals how galactic winds carry this material away from sites of new star creation and out into intergalactic space.
Researchers at the Stratospheric Observatory for Infrared Astronomy (SOFIA) looked at the Cigar Galaxy, also known as M82, which is famous for producing new stars at a tremendous speed. In this galaxy, stars are born 10 times faster than they are here in our Milky Way. As well as this unusual feature, the Cigar Galaxy has particularly strong galactic winds — streams of highly charged particles which shoot off into space when new stars are formed. This makes it the ideal location to observe how gas and dust are carried out into intergalactic space.
Using the SOFIA flying observatory, the astronomers were able to observe the magnetic field of the Cigar Galaxy and see how it related to the movement of galactic winds. They found that the powerful winds moved not only matter but also the magnetic field itself, dragging it more than 2,000 light-years across.
“One of the main objectives of this research was to evaluate how efficiently the galactic wind can drag along the magnetic field,” Enrique Lopez-Rodriguez, a Universities Space Research Association (USRA) scientist working on the SOFIA team, said in a statement. “We did not expect to find the magnetic field to be aligned with the wind over such a large area.”
This finding suggests that the galactic winds could be responsible for seeding new galaxies as they carry not only gas and dust but also a magnetic field into the intergalactic medium, which would encourage stars and eventually galaxies to form. This is also relevant to understanding how the earliest galaxies formed at the start of the universe.
“Studying intergalactic magnetic fields — and learning how they evolve — is key to understanding how galaxies evolved over the history of the universe,” lead researcher for this study, Terry Jones, professor emeritus at the University of Minnesota, Minneapolis, said in the same statement. “We now have a new perspective on these magnetic fields.”
The findings are published in the Astrophysical Journal Letters.
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