SNELLS-HD – I. A first look at the stellar properties of the massive strong-lens galaxy SNL-1 with 50 pc resolution

Journal article

We present a dynamical and chemical study of the centre of a massive early-type strong-lens galaxy ESO 286−G022 (SNL-1). Analysing new data obtained through the adaptive-optics-assisted Narrow-Field Mode of Very Large Telescope/Multi-Unit Spectroscopic Explorer, we aim to measure the mass distribution and internal properties of SNL-1 at resolution. In particular, we aim to address the tension in the reported initial mass function (IMF) measurements of SNL-1 between strong-lens/dynamical and spectral-fitting techniques. We fit a triaxial orbital dynamical model to the measured stellar kinematics, including constraining the mass of the (resolved) central supermassive black hole. The dynamical model is consistent with the mass-to-light ratio expected for a Kroupa-like IMF. We also employ a highly flexible spectral-fitting technique, which instead favours a Salpeter-like IMF (low-mass slope ) over the same spatial region. To conclude, we discuss possible origins of this discrepancy, both intrinsic and technical.

Authors: Poci, A; Smith, RJ

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Oxford University Press
• Journal: Monthly Notices of the Royal Astronomical Society
• Volume: 543
• Issue: 2
• Pages: 1373-1392
• Publication date: 2025-09-08
• Acceptance date: 2025-09-01
• DOI: 10.1093/mnras/staf1491
• EISSN: 1365-2966
• ISSN: 0035-8711
• Language: English
• Keywords: galaxies: structure; galaxies: kinematics and dynamics; galaxies: elliptical and lenticular, cD; galaxies: stellar content