Hot gas feeds spiral arms of the Milky Way
(PHYSorg.com Space & Earth)

An international research team, with significant participation of astronomers from the Max Planck Institute for Astronomy (MPIA), has gained important insights into the origin of the material in the spiral arms of the Milky Way, from which new stars are ultimately formed. By analysing properties of the galactic magnetic field, they were able to show that the dilute so-called warm ionized medium (WIM), in which the Milky Way is embedded, condenses near a spiral arm. While gradually cooling, it serves as a supply of the colder material of gas and dust that feeds star formation.