Astronomers at the National Radio Astronomy Observatory discovered a cluster of hydrogen clouds between our two nearby galaxies- Triangulum (M33) and Andromeda (M31). The cluster of these clouds was never seen before. The researchers contemplated that these were the rare blobs of gas condensed from gigantic and undetected pool of ionized and hot gas.
These objects were detected by the astronomers by making use of National Science Foundation's Green Bank Telescope (GBT) at the National Radio Astronomy Observatory (NRAO) in Green Bank.
Spencer Wolfe of West Virginia University in Morgantown explained that when the area between M31 and M33 was observed, presence of neutral and colder hydrogen was detected but the astronomers were not able to find out if this hydrogen had any definitive structure or not. But with the help of high resolution images sent by GBT, the astronomers were able to see distinct concentrations of neutral hydrogen which emerged from featureless field of gas.
The astronomers were able to see neutral atomic hydrogen, also referred to as HI (H and the Roman numeral one). This is because of the unique signal that it emits at the radio wavelengths that can be detected on our planet by the radio telescopes. It is interesting to notice that this material is found abundantly throughout the universe, but in space between the galaxies, it is very shaky. Also, between the two signals, it sends very faint signals which are very difficult to catch.
Astronomers explained that more than 10 years ago, they had hint about unrecognized abundance of hydrogen lying between M31 and M33. But because of very faint signal from the gas, no firm conclusions about the origin, nature or its existence could be made. But in 2012, data from GBT confirmed the presence of hydrogen gas between the nearest galaxies.
Thorough studies of the data from GBT revealed that presence of hydrogen gas was not there in the form of just streamers but a complete 50 percent of hydrogen was clustered into discrete and self-gravitating blobs. These blobs could also hint towards dwarf galaxies, which, as the name says, are small collection of stars tied together by gravitational pull. These dwarf galaxies contain a few thousands to few million stars.
Interestingly, GBT also tracked motion of the newly discovered clouds of hydrogen, depicting that these were travelling across the space at velocities which were like M31 and M33. Felix J. Lockman, the astronomer from NRAO in Green Bank explained that the clouds had their own identities and that they were not suburbs of either of the two galaxies.
The reason why GBT could detect the signal from the gas is because of it huge size, exceptional design and location at National Radio Quiet Zone of West Virginia. Otherwise, radio telescopes could not catch these faint signals.
National Radio Astronomy Observatory is the facility of National Science Foundation which is operated under the cooperative agreement by Associated Universities.