2025MNRAS.543.1373P

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 ${\sim} 50 \, {\rm pc}$ 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 $\alpha \approx 2.3$) over the same spatial region. To conclude, we discuss possible origins of this discrepancy, both intrinsic and technical.