An international team of researchers has discovered a dense, cold gas that has been shot out of the center of the Milky Way “Like bullets.”
Exactly how the gas is exposed is still a mystery, but the research team, including Professor Naomi McClure-Griffiths from The Australian National University (ANU), say that their findings could have important implications for the future of our galaxy.
“Galaxies can be really good at shooting themselves in the foot,” said Professor McClure-Griffiths.
‘If you expel a lot of mass, you lose some material that could be used to form stars, and if you lose enough of it, the galaxy can no longer form stars.
“So, to see hints of the Milky Way losing this star-forming gas is pretty exciting – it makes you wonder what will happen next!”
The Atacama Pathfinder Experiment (APEX), on the 5000 meter high plateau of Chajnantor in the Chilean Andes. Credit: ESO / B. Tafreshi / TWAN (twanight.org)
The study also raises new questions about what is happening right now in our galactic center.
“The wind at the center of the Milky Way has been the subject of much debate since the discovery a decade ago of the so-called Fermi Bubbles – two giant orbs filled with hot gas and cosmic rays,” said Professor McClure-Griffiths.
‘We have noticed that not only hot gas comes from the center of our galaxy, but also cold and very dense gas.
“This cold gas is much heavier, so moves less easily.”
The center of the Milky Way is home to a mass black hole, but it is unclear whether this black hole displaced the gas, or whether it was blown by the thousands of massive stars in the center of the galaxy.
“We do not know how the black hole as the star formation can produce this phenomenon. We are still looking for the smoke gun, but it gets more complicated the more we learn from it, “said lead author Dr. Enrico Di Teodoro of Johns Hopkins University.
‘This is the first time such a thing has been observed in our galaxy. We see this kind of process happening in other galaxies. But, with external galaxies you get much more massive black holes, the star formation activity is higher, it makes it easier for the galaxy to expel material.
‘And these other galaxies are apparently a long way off, we can not see them in much detail.
“Our own galaxy is almost like a lab that we can actually get into and try to understand how things work by looking closely.”
The study was published in the journal Nature.
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Reference: August 19, 2020, Nature.
DOI: 10.1038 / s41586-020-2595-z
The gas was observed with the Atacama Pathfinder EXperiment (APEX) operated by the European Southern Observatory (ESO) in Chile.
