Star formation in galaxies takes place in filaments composed of gas (mainly hydrogen) and small solid particles called interstellar dust, which is mainly carbon. Depending on the location of these filaments and their physical properties (density, temperature) they can be difficult to detect in the data. In particular, low density filaments or filaments located in areas of very high emission are generally not detected.
Click here for original story, Detecting galactic filaments with machine learning
Source: Phys.org