Looking for Systematic Variations in the Stellar Initial Mass Function

Understand

Few topics in astronomy initiate such vigorous discussion as whether or not the initial mass function (IMF) of stars is universal, or instead sensitive to the initial conditions of star formation.

• The distinction is of critical importance: the IMF influences most of the observable properties of stellar populations and galaxies, and detecting variations in the IMF could provide deep insights into the process by which stars form.
• In this contribution, we take a critical look at the case for IMF variations, with a view towards whether other explanations are sufficient given the evidence.
• Studies of the field, local young clusters and associations, and old globular clusters suggest that the vast majority were drawn from a "universal" IMF.