MUSE-DARK-II: 3D morpho-kinematic modelling of lensed galaxies. Tully-Fisher relation of $z \sim 1$ star-forming galaxies

TL;DR

This paper presents a new methodology for 3D morpho-kinematic modelling of lensed galaxies, validating it with mock data, and investigates the evolution of Tully-Fisher relations since redshift 1, finding significant stellar mass evolution but stable baryonic mass relations.

Contribution

The paper introduces and validates a lensing-aware 3D modelling method for lensed galaxies and studies Tully-Fisher relation evolution over the past 8 billion years.

Findings

Significant evolution in the stellar-mass Tully-Fisher relation zero-point.

No detectable evolution in the baryonic-mass Tully-Fisher relation zero-point.

Method outperforms approaches ignoring differential magnification.

Abstract

In a series of papers on lensed kinematics, we seek to combine the sensitivity of 3D forward modelling to low signal-to-noise ratio outskirts with the enhanced spatial resolution of cluster lensing. In this first paper, we (i) present and validate our methodology, which directly constrains the source parameters by incorporating lensing deflections into the $\texttt{GalPaK}^\texttt{3D}$ forward-modelling algorithm, and (ii) investigate the evolution of the stellar-mass and baryonic-mass Tully-Fisher relations (sTFR and bTFR) since $z \sim 1$. We define a robust sample of strongly lensed star-forming galaxies (SFGs) from the MUSE Lensing Cluster survey, spanning magnifications $\mu = 1.4 - 12.4$ and stellar masses $M_\star = 10^{8.1} - 10^{10.3} M_\odot$. Using a series of mock galaxies, we find that our method is significantly more reliable at recovering morpho-kinematic properties than approaches that ignore differential magnification, even for relatively modest magnifications ($\mu < 6$). Restricting the analysis to 95 rotationally supported SFGs with well-constrained velocities, we find a significant evolution of the sTFR zero-point ($\Delta b^\mathrm{sTFR} = -0.42^{+0.05}_{-0.05}~\mathrm{dex}$ in stellar mass) but no detectable evolution of the bTFR zero-point ($\Delta b^\mathrm{bTFR} = 0.00^{+0.06}_{-0.06}~\mathrm{dex}$ in baryonic mass) relative to $z \approx 0$. Our results are consistent with a mild evolution of the stellar-to-halo mass ratio and support the view that the sTFR has evolved only weakly over the past $\sim 8$ Gyr, aside from shifts driven by the redshift dependence of halo-defining quantities such as the critical density and overdensity. The absence of detectable evolution in the bTFR zero-point suggests that the increasing contribution of cold gas mass at higher redshift fully compensates the evolution observed in the stellar component alone. [abridged]