“We’re still looking for the smoking gun, but it gets more complicated the more we learn about it,” say the researchers.
Scientists have discovered a mysterious cold gas being shot out of the centre of the Milky Way galaxy, but are puzzled as to what could have produced it.
Researchers are concerned that the strange gas – which has been shot “like bullets” from the galactic centre, although astronomers don’t yet know how – could have critical implications for the future of the galaxy.
“Galaxies can be really good at shooting themselves in the foot,” said Professor Naomi McClure-Griffiths from The Australian National University.
“When you drive out a lot of mass, you’re losing some of the material that could be used to form stars, and if you lose enough of it, the galaxy can’t form stars at all anymore.
“So, to be able to see hints of the Milky Way losing this star forming gas is kind of exciting – it makes you wonder what’s going to happen next!”
The study, which has been published in the journal Nature, also poses new questions regarding an ongoing debate about the centre of the galaxy.
“The wind at the centre of the Milky Way has been the topic of plenty of debate since the discovery a decade ago of the so-called Fermi Bubbles – two giant orbs filled with hot gas and cosmic rays,” added Professor McClure-Griffiths.
“We’ve observed there’s not only hot gas coming from the centre of our galaxy, but also cold and very dense gas. This cold gas is much heavier, so moves around less easily,” she said.
The centre of the galaxy is a chaotic place governed by extremely powerful forces, including a supermassive black hole – but it isn’t clear which of those forces could have caused the gas to be shot out.
“We don’t know how either the black hole or the star formation can produce this phenomenon. We’re still looking for the smoking gun, but it gets more complicated the more we learn about it,” added Dr Enrico Di Teodoro, the lead author on the study, from Johns Hopkins University.