Jul 14, 2018 05:11 PM
https://www.sciencenews.org/article/cosm...ming-focus
EXCERPT: . . . Much of that turmoil takes place in a huge, complicated setting called the circumgalactic medium, or CGM. This vast, roiling cloud of dust and gas is a galaxy’s fuel source, waste dump and recycling center all in one. Astronomers think the answers to some of the most pressing galactic mysteries — how galaxies keep forming new stars for billions of years, why star formation abruptly stops — are hidden in a galaxy’s enveloping CGM. “To understand the galaxies, you have to understand the ecosystem that they’re in,” says astronomer Molly Peeples of the Space Telescope Science Institute in Baltimore.
Yet this galactic atmosphere is so diffuse that it’s invisible — a liter of CGM contains just a single atom. It has taken almost 60 years and an upgrade to the Hubble Space Telescope just to begin probing distant CGMs and figuring out how their constant churning can make or break galaxies. “Only recently have we been able to really, truly, observationally characterize the relationship between this gaseous cycle and the properties of the galaxy itself,” [Jessica] Werk says...
MORE: https://www.sciencenews.org/article/cosm...ming-focus
EXCERPT: . . . Much of that turmoil takes place in a huge, complicated setting called the circumgalactic medium, or CGM. This vast, roiling cloud of dust and gas is a galaxy’s fuel source, waste dump and recycling center all in one. Astronomers think the answers to some of the most pressing galactic mysteries — how galaxies keep forming new stars for billions of years, why star formation abruptly stops — are hidden in a galaxy’s enveloping CGM. “To understand the galaxies, you have to understand the ecosystem that they’re in,” says astronomer Molly Peeples of the Space Telescope Science Institute in Baltimore.
Yet this galactic atmosphere is so diffuse that it’s invisible — a liter of CGM contains just a single atom. It has taken almost 60 years and an upgrade to the Hubble Space Telescope just to begin probing distant CGMs and figuring out how their constant churning can make or break galaxies. “Only recently have we been able to really, truly, observationally characterize the relationship between this gaseous cycle and the properties of the galaxy itself,” [Jessica] Werk says...
MORE: https://www.sciencenews.org/article/cosm...ming-focus