Tools
Tools
Barber, C, Crain, RA and Schaye, J (2018) Calibrated, cosmological hydrodynamical simulations with variable IMFs I: Method and effect on global galaxy scaling relations. Monthly Notices of the Royal Astronomical Society, 479 (4). pp. 5448-5473. ISSN 0035-8711
|
Text
sty1826.pdf - Published Version Download (5MB) | Preview |
Abstract
The recently inferred variations in the stellar initial mass function (IMF) among local highmass early-type galaxies may require a reinterpretation of observations of galaxy populations and may have important consequences for the predictions of models of galaxy formation and evolution. We present a new pair of cosmological, hydrodynamical simulations based on the EAGLE model that self-consistently adopts an IMF that, respectively, becomes bottomor top-heavy in high-pressure environments for individual star-forming gas particles. In such models, the excess stellarmass-to-light (M/L) ratio with respect to a reference IMF is increased due to an overabundance of low-mass dwarf stars or stellar remnants, respectively. Crucially, both pressure-dependent IMFs have been calibrated to reproduce the observed trends of increasing excessM/L with central stellar velocity dispersion (σe) in early-type galaxies, while maintaining agreement with the observables used to calibrate the EAGLE model, namely the galaxy luminosity function, half-light radii of late-type galaxies, and black holemasses.We find that while theM/L excess is a good measure of the IMF for low-mass slope variations, it depends strongly on the age of the stellar population for high-mass slope variations. The normalization of the [Mg/Fe]-σerelation is decreased (increased) for bottom- (top-)heavy IMF variations, while the slope is not strongly affected. Bottom-heavy variations have little impact on galaxy metallicities, half-light radii of early-type galaxies, or star formation rates, while top-heavy variations significantly increase these quantities for high-mass galaxies, leading to tension with observations. © 2018 The Author(s). Published by Oxford University Press on behalf of The Royal Astronomical Society.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | 0201 Astronomical And Space Sciences |
| Subjects: | Q Science > QB Astronomy Q Science > QC Physics |
| Divisions: | Astrophysics Research Institute |
| Publisher: | Oxford University Press |
| Date Deposited: | 05 Sep 2018 09:57 |
| Last Modified: | 04 Sep 2021 10:09 |
| DOI or ID number: | 10.1093/mnras/sty1826 |
| URI: | https://researchonline.ljmu.ac.uk/id/eprint/9162 |
 |
View Item |