Breakthrough on star formation

An important new hint regarding how galaxies halt intense episodes of star formation has been found by astronomers using the Karl G Jansky Very Large Array (VLA) of the National Science Foundation in the United States (US).

The research on the nearby galaxy M33 suggests that fast cosmic ray electrons can generate winds that blow away the gas required for the formation of new stars. As galaxies evolve over time, these winds are what cause the star formation rate to slow down. However, the primary sources of such winds have been attributed to material jets powered by black holes and shock waves from supernova explosions.

Cosmic rays were assumed to be small contributors, especially in galaxies with prolific star formation, such as M33. M33 is a spiral galaxy that is almost 3 million light-years distant and is a member of the Local Group of galaxies, which also contains the Milky Way.