A systematic variation of the stellar initial mass function in early-type galaxies

Understand

Much of our knowledge of galaxies comes from analysing the radiation emitted by their stars.

• It depends on the stellar initial mass function (IMF) describing the distribution of stellar masses when the population formed.
• Consequently knowledge of the IMF is critical to virtually every aspect of galaxy evolution.
• More than half a century after the first IMF determination, no consensus has emerged on whether it is universal in different galaxies.