Astronomers have obtained an image of cold molecular gas outside galaxies. article about it published in the journal Science.
For many years, scientists assumed that streams of cold gas formed in space sometimes entering galaxies, where they fed star formation. However, this was difficult to prove due to the cold nature of the streams and therefore they emit very little energy and are not in the range that is easy to observe.
Now Bjorn Emonts and his colleagues have been able to detect such a stream feeding the galaxy 4C 41.17. Observations were made with the ALMA millimeter telescope in Chile. The discovered stream is composed mainly of carbon and is over half a million light-years in length. At the same time, the estimate of the composition can be inaccurate, and scientists do not have data on where this flow is coming from.
The authors plan to continue the work using the Very Large Array radio telescope, which could also theoretically detect traces of carbon monoxide in the predicted flow. Additionally, the scientists want to identify key features that will enable them to find similar flows in the future, as well as create a model for the accumulation of this gas in galaxies.