Evidence in Favour of IMF Variations

Abstract

The stellar initial mass function (IMF) determines the relative number of stars born at a given mass. Despite the tremendous effort to establish a universal IMF, the astronomical literature offers a wealth of diverse evidence for IMF variations. This review was prepared for a controversial debate at the conference ``Starbursts -- Near and Far'' at Ringberg Castle, 2000, and gives a one-sided portrayal in favour of IMF variations. I will summarise the empirical evidence that the IMF varies with time, with environment, and for all stellar masses. While I see no obvious systematic trend in most regions of our Galaxy, there is at least an indication that the IMF is biased towards more massive stars in the early universe and in starbursts.

arXiv comment10 pages, 1 figure, invited review, to appear in the conference proceedings of "Starbursts: Near and Far", Ringberg Castle, Germany, 10-15 September 2000 (eds. L.J. Tacconi and D. Lutz)

References in corpus (10)

• Starburst99: Synthesis Models for Galaxies with Active Star Formation
• The Luminosity Function of Young Star Clusters In "The Antennae" Galaxies (NGC 4038/4039)
• Early Star Formation and the Evolution of the Stellar Initial Mass Function in Galaxies
• HST/NICMOS Observations of Massive Stellar Clusters Near the Galactic Center
• The Initial Mass Function of Low-Mass Stars and Brown Dwarfs in Young Clusters
• Low-Mass Star Formation and the Initial Mass Function in the Rho Ophiuchi Cloud Core
• L Dwarfs and the Substellar Mass Function
• The Initial Mass Function of Low-Mass Stars and Brown Dwarfs in Taurus
• Dynamical Evidence for a Luminous, Young Globular Cluster in NGC 1569
• The Initial Mass Functions in the Super-Star-Clusters NGC 1569A and NGC 1705-1

Cited by in corpus (8)

• Kinematic Masses of Super Star Clusters in M82 from High-Resolution Near-Infrared Spectroscopy
• Top-heavy integrated galactic stellar initial mass functions (IGIMFs) in starbursts
• Chemical evolution of starburst galaxies: How does star formation proceed?
• The near-IR Ca II triplet - sigma relation for bulges of spiral galaxies
• The stellar IMF of Galactic clusters and its evolution
• Low-Mass Pre-Main Sequence Stars in the Large Magellanic Cloud - III: Accretion Rates from HST-WFPC2 Observations
• Galactic Models and White Dwarf Populations
• The initial mass function of the rich young cluster NGC 1818 in the Large Magellanic Cloud