A new strong-lensing galaxy at z=0.066: Another elliptical galaxy with a lightweight IMF

Collier, William P.; Smith, Russell J.; Lucey, John R.

doi:10.1093/mnras/sty1188

A new strong-lensing galaxy at z=0.066: Another elliptical galaxy with a lightweight IMF

Collier, William P.; Smith, Russell J.; Lucey, John R.

Authors

William P. Collier

Dr Russell Smith russell.smith@durham.ac.uk
Assistant Professor

Dr John Lucey john.lucey@durham.ac.uk
Emeritus Professor

Abstract

We report the discovery of a new low-redshift galaxy-scale gravitational lens, identified from a systematic search of publicly available MUSE observations. The lens galaxy, 2MASXJ04035024-0239275, is a giant elliptical at z = 0.06604 with a velocity dispersion of σ = 314 km s−1. The lensed source has a redshift of 0.19165 and forms a pair of bright images on either side of the lens centre. The Einstein radius is 1.5 arcsec, projecting to 1.8 kpc, which is just one quarter of the galaxy effective radius. After correcting for an estimated 19 per cent dark matter contribution, we find that the stellar mass-to-light ratio from lensing is consistent with that expected for a Milky Way initial mass function (IMF). Combining the new system with three previously-studied low-redshift lenses of similar σ, the derived mean mass excess factor (relative to a Kroupa IMF) is ⟨α⟩ = 1.09±0.08. With all four systems, the intrinsic scatter in α for massive elliptical galaxies can be limited to <0.32, at 90 per cent confidence.

Citation

Collier, W. P., Smith, R. J., & Lucey, J. R. (2018). A new strong-lensing galaxy at z=0.066: Another elliptical galaxy with a lightweight IMF. Monthly Notices of the Royal Astronomical Society, 478(2), 1595-1600. https://doi.org/10.1093/mnras/sty1188

Journal Article Type	Article
Acceptance Date	May 3, 2018
Online Publication Date	May 7, 2018
Publication Date	Aug 1, 2018
Deposit Date	Apr 3, 2018
Publicly Available Date	May 11, 2018
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	478
Issue	2
Pages	1595-1600
DOI	https://doi.org/10.1093/mnras/sty1188
Related Public URLs	https://arxiv.org/abs/1803.07082

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This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society ©: 2018 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.