Vast reservoir of gas may fuel star creation in our galaxy
The Milky Way may have found a solution to its gas shortage. Astronomers had calculated that our home galaxy possesses only enough fuel to forge new stars for just a few billion more years. But scientists have now discovered that a long stream of gas falling into the Milky Way is four times as massive as previously thought and could power our galaxy's starmaking career for a long time to come.
"It's a very beautiful study with surprising results," says Leo Blitz of the University of California, Berkeley, an astronomer who was not part of the project.
Astronomer Andrew Fox of the Space Telescope Science Institute in Baltimore, Maryland, and his colleagues made the discovery while studying a stream of gas shed by two nearby galaxies, the Large and Small Magellanic Clouds, which orbit the Milky Way. The lost Magellanic gas stretches over more than half a million light-years of space, and much of it will fall into our galaxy's disk, supplying fuel for new stars. Astronomers discovered this gas long ago because it contains hydrogen, the most abundant element in space.
But this gas isn’t always easy to detect. It comes in different varieties. One is a neutral, or nonionized, form, in which each proton has an electron; this type of gas emits 21-centimeter-long radio waves that radio telescopes readily spot. But the gas also comes in an ionized form, in which electrons are free of protons; this type of gas doesn't emit these radio waves and so can be much harder to detect.
Image of Milky Way via Shutterstock.
Read more at Science.