Dr Russell Smith russell.smith@durham.ac.uk
Assistant Professor
Stellar dynamics in the strong-lensing central galaxy of Abell 1201: a low stellar mass-to-light ratio, a large central compact mass and a standard dark matter halo
Smith, Russell J.; Lucey, John R.; Edge, Alastair C.
Authors
Dr John Lucey john.lucey@durham.ac.uk
Emeritus Professor
Professor Alastair Edge alastair.edge@durham.ac.uk
Professor
Abstract
We analyse the stellar kinematics of the z = 0.169 brightest cluster galaxy in Abell 1201, using integral field observations acquired with the Multi-Unit Spectroscopic Explorer on the Very Large Telescope. This galaxy has a gravitationally lensed arc located at unusually small radius (∼5 kpc), allowing us to constrain the mass distribution using lensing and stellar dynamical information over the same radial range. We measure a velocity dispersion profile which is nearly flat at σ ≈ 285 km s−1 in the inner ∼5 kpc, and then rises steadily to σ ≈ 360 km s−1 at ∼30 kpc. We analyse the kinematics using axisymmetric Jeans models, finding that the data require both a significant dark matter halo (to fit the rising outer profile) and a compact central component, with mass Mcen ≈ 2.5 × 1010 M⊙ (to fit the flat σ in the inner regions). The latter component could represent a supermassive black hole, in which case it would be among the largest known to date. Alternatively Mcen could describe excess mass associated with a gradient in the stellar mass-to-light ratio. Imposing a standard Navarro–Frenk–White (NFW) dark matter density profile, we recover a stellar mass-to-light ratio ϒ, which is consistent with a Milky Way-like initial mass function (IMF). By anchoring the models using the lensing mass constraint, we break the degeneracy between ϒ and the inner slope γ of the dark matter profile, finding γ = 1.0 ± 0.1, consistent with the NFW form. We show that our results are quite sensitive to the treatment of the central mass in the models. Neglecting Mcen biases the results towards both a heavier-than-Salpeter IMF and a shallower-than-NFW dark matter slope (γ ≈ 0.5).
Citation
Smith, R. J., Lucey, J. R., & Edge, A. C. (2017). Stellar dynamics in the strong-lensing central galaxy of Abell 1201: a low stellar mass-to-light ratio, a large central compact mass and a standard dark matter halo. Monthly Notices of the Royal Astronomical Society, 471(1), 383-393. https://doi.org/10.1093/mnras/stx1573
Journal Article Type | Article |
---|---|
Acceptance Date | Jun 20, 2017 |
Online Publication Date | Jun 22, 2017 |
Publication Date | Oct 11, 2017 |
Deposit Date | Sep 21, 2017 |
Publicly Available Date | Oct 6, 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 | 471 |
Issue | 1 |
Pages | 383-393 |
DOI | https://doi.org/10.1093/mnras/stx1573 |
Public URL | https://durham-repository.worktribe.com/output/1348759 |
Related Public URLs | https://arxiv.org/abs/1706.07055 |
Files
Published Journal Article
(1.6 Mb)
PDF
Copyright Statement
This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society ©: 2017 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.
You might also like
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
A systematic survey for z< 0.04 CLAGNs
(2021)
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