Is the Stellar Initial Mass Function Truly Universal?

by Prof. Charles Steinhardt

DAWN, Niels Bohr Institute, Denmark
at Astrophysics and Cosmology Seminar

Tue, 14 Mar 2023, 10:10
Sacta-Rashi Building for Physics (54), room 207


Current techniques for analyzing large photometric catalogs are generally forced to assume a single, universal stellar initial mass function (IMF), although the IMF should be expected to vary depending upon conditions within a star-forming galaxy. The introduction of an additional parameter into photometric template fitting allows galaxies to be fit with a range of different IMFs. Most galaxies are best fit with a bottom-lighter IMF than the Milky Way, and this change in IMF also modifies inferred properties such as stellar mass and star formation rate. Several surprising new features appear, including significant constraints on the feedback mechanisms responsible for star formation and subsequent quenching. Additionally, the same techniques might indicate that most galaxies go through an earliest phase of star formation dominated by different feedback mechanisms and centred in galactic cores prior to the more typical star formation at later times.

Created on 12-03-2023 by Zitrin, Adi (zitrin)
Updaded on 12-03-2023 by Zitrin, Adi (zitrin)