Padraig D. Alton
KINETyS: Constraining spatial variations of the stellar initial mass function in early-type galaxies
Alton, Padraig D.; Smith, Russell J.; Lucey, John R.
Authors
Dr Russell Smith russell.smith@durham.ac.uk
Assistant Professor
John Lucey john.lucey@durham.ac.uk
Emeritus Professor
Abstract
The heavyweight stellar initial mass function (IMF) observed in the cores of massive early-type galaxies (ETGs) has been linked to formation of their cores in an initial swiftly quenched rapid starburst. However, the outskirts of ETGs are thought to be assembled via the slow accumulation of smaller systems in which the star formation is less extreme; this suggests that the form of the IMF should exhibit a radial trend in ETGs. Here, we report radial stellar population gradients out to the half-light radii of a sample of eight nearby ETGs. Spatially resolved spectroscopy at 0.8–1.35 μm from the Very Large Telescope's K-band Multi-Object Spectrograph instrument was used to measure radial trends in the strengths of a variety of IMF-sensitive absorption features (including some which are previously unexplored). We find weak or no radial variation in some of these which, given a radial IMF trend, ought to vary measurably, e.g. for the Wing–Ford band, we measure a gradient of +0.06 ± 0.04 per decade in radius. Using stellar population models to fit stacked and individual spectra, we infer that the measured radial changes in absorption feature strengths are primarily accounted for by abundance gradients, which are fairly consistent across our sample (e.g. we derive an average [Na/H] gradient of −0.53 ± 0.07). The inferred contribution of dwarf stars to the total light typically corresponds to a bottom-heavy IMF, but we find no evidence for radial IMF variations in the majority of our sample galaxies.
Citation
Alton, P. D., Smith, R. J., & Lucey, J. R. (2017). KINETyS: Constraining spatial variations of the stellar initial mass function in early-type galaxies. Monthly Notices of the Royal Astronomical Society, 468(2), 1594-1615. https://doi.org/10.1093/mnras/stx464
Journal Article Type | Article |
---|---|
Acceptance Date | Feb 21, 2017 |
Online Publication Date | Feb 23, 2017 |
Publication Date | Feb 23, 2017 |
Deposit Date | May 8, 2017 |
Publicly Available Date | May 9, 2017 |
Journal | Monthly Notices of the Royal Astronomical Society |
Print ISSN | 0035-8711 |
Electronic ISSN | 1365-2966 |
Publisher | Royal Astronomical Society |
Peer Reviewed | Peer Reviewed |
Volume | 468 |
Issue | 2 |
Pages | 1594-1615 |
DOI | https://doi.org/10.1093/mnras/stx464 |
Public URL | https://durham-repository.worktribe.com/output/1359489 |
Related Public URLs | https://arxiv.org/abs/1702.05485 |
Files
Published Journal Article
(6 Mb)
PDF
Copyright Statement
This article has been published in Monthly Notices of the Royal Astronomical Society ©: 2016 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.
You might also like
Galaxy and Mass Assembly (GAMA): Stellar-to-dynamical Mass Relation. II. Peculiar Velocities
(2024)
Journal Article
Abell 1201: detection of an ultramassive black hole in a strong gravitational lens
(2023)
Journal Article
The Sloan Digital Sky Survey peculiar velocity catalogue
(2022)
Journal Article
Downloadable Citations
About Durham Research Online (DRO)
Administrator e-mail: dro.admin@durham.ac.uk
This application uses the following open-source libraries:
SheetJS Community Edition
Apache License Version 2.0 (http://www.apache.org/licenses/)
PDF.js
Apache License Version 2.0 (http://www.apache.org/licenses/)
Font Awesome
SIL OFL 1.1 (http://scripts.sil.org/OFL)
MIT License (http://opensource.org/licenses/mit-license.html)
CC BY 3.0 ( http://creativecommons.org/licenses/by/3.0/)
Powered by Worktribe © 2024
Advanced Search