Zee Media Bureau
Washington: Astronomers have discovered a river of hydrogen flowing through space and into a nearby galaxy.
The discovery, most likely the first of its kind to be ever documented, could help explain how certain spiral galaxies keep up their steady pace of star formation.
Using National Science Foundation`s Green Bank Telescope (GBT), astronomer DJ Pisano from West Virginia University spotted the very faint, very tenuous filament of gas streaming into the nearby galaxy NGC 6946.
“We knew that the fuel for star formation had to come from somewhere, asserting that so far, however, they`ve detected only about 10 percent of what would be necessary to explain what we observe in many galaxies,” Pisano said.
“A leading theory is that rivers of hydrogen - known as cold flows - may be ferrying hydrogen through intergalactic space, clandestinely fuelling star formation. But this tenuous hydrogen has been simply too diffuse to detect, until now," he added.
Spiral galaxies, like our own Milky Way, typically maintain a rather tranquil but steady pace of star formation. Others, like NGC 6946, which is located approximately 22 million light-years from Earth on the border of the constellations Cepheus and Cygnus, are much more active, though less-so than more extreme starburst galaxies.
This raises the question of what is fuelling the sustained star formation in this and similar spiral galaxies.
Using the GBT, Pisano was able to detect the glow emitted by neutral hydrogen gas connecting NGC 6946 with its cosmic neighbors.
Astronomers have long theorized that larger galaxies could receive a constant influx of cold hydrogen by syphoning it off other less-massive companions.
The results have been published in the Astronomical Journal.
(With Agency Input)
