Simultaneous measurement of low- and high-mass IMF slopes in 214 star-forming galaxies reveals diversity, weak correlation between ends, and links to stellar mass, star formation rate, and metallicity.
A systematic variation of the stellar initial mass function in early-type galaxies
3 Pith papers cite this work. Polarity classification is still indexing.
abstract
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. Previous studies indicated that the IMF and the dark matter fraction in galaxy centres cannot be both universal, but they could not break the degeneracy between the two effects. Only recently indications were found that massive elliptical galaxies may not have the same IMF as our Milky Way. Here we report unambiguous evidence for a strong systematic variation of the IMF in early-type galaxies as a function of their stellar mass-to-light ratio, producing differences up to a factor of three in mass. This was inferred from detailed dynamical models of the two-dimensional stellar kinematics for the large Atlas3D representative sample of nearby early-type galaxies spanning two orders of magnitude in stellar mass. Our finding indicates that the IMF depends intimately on a galaxy's formation history.
fields
astro-ph.GA 3years
2026 3verdicts
UNVERDICTED 3representative citing papers
In 37 massive ETGs, the IMF becomes less bottom-heavy with radius, with average α_IMF falling from 2.16 to 1.74 and IMF gradients dominating M/L variations over stellar population effects.
Non-Gaussian LSF shapes bias kinematic extraction from spectra; matching the LSF of templates to the target reduces dispersion bias below 1%.
citing papers explorer
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Hector Galaxy Survey: Linking the low- and high-mass ends of the initial mass function in star-forming galaxies
Simultaneous measurement of low- and high-mass IMF slopes in 214 star-forming galaxies reveals diversity, weak correlation between ends, and links to stellar mass, star formation rate, and metallicity.
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The MASSIVE SURVEY XXI: Local Variations in the Stellar Initial Mass Function of MASSIVE Early-Type Galaxies
In 37 massive ETGs, the IMF becomes less bottom-heavy with radius, with average α_IMF falling from 2.16 to 1.74 and IMF gradients dominating M/L variations over stellar population effects.
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The Impact of Non-Gaussian Line Spread Functions on Stellar Kinematic Recovery: Consequences for Dynamical Models
Non-Gaussian LSF shapes bias kinematic extraction from spectra; matching the LSF of templates to the target reduces dispersion bias below 1%.