Astronomer has seen the river of hydrogen flowing through space with the help of NSF’s Robert C. Byrd Green Bank Telescope (GBT).
The Astronomical Journal
The data presented by GBT is showing that the shining hydrogen is present between the larger galaxy and its smaller companions. Hydrogen can be seen in the image in the form of dense hydrogen in orange color and the extremely diffuse and extended field of hydrogen in red color. In the image above, blue color shows the bright star-filled central region of galaxy NGC 6946 in optical light.
“We knew that the fuel for star formation had to come from somewhere. So far, however, we’ve detected only about 10 percent of what would be necessary to explain what we observe in many galaxies,” astronomer D. J. Pisano from West Virginia University, said in a statement. “A leading theory is that rivers of hydrogen — known as cold flows — may be ferrying hydrogen through intergalactic space, clandestinely fueling star formation. But this tenuous hydrogen has been simply too diffuse to detect, until now.”
NGC 6946 is located about 22 million light-years away from us. It is present on the border of constellations Cepheus and Cygnus. In the image, this galaxy is found to be connected to the neighboring galaxy by neutral hydrogen gas.
River of Hydrogen Flowing Through Space – Space Ref (http://goo.gl/kB3ytr)
D. J. Pisano (2014). Green Bank Telescope observations of low column density HI around NGC 2997 and NGC 6946 The Astronomical Journal DOI: 10.1088/0004-6256/147/3/48