The KMOS Deep Survey (KDS) II: The evolution of the stellar-mass Tully-Fisher relation since z ~ 4

Understand

We use KMOS Deep Survey (KDS) galaxies, combined with results from a range of spectroscopic studies in the literature, to investigate the evolution of the stellar-mass Tully-Fisher relation since z ~ 4.

• We determine the slope and normalisation of the local rotation-velocity -- stellar-mass (Vc - $M_{\star}$) relationship using a reference sample of local spiral galaxies; thereafter we fix the slope, and focus on the evolution of velocity normalisation with redshift.
• The rotation-dominated KDS galaxies at z ~ 3.5 have rotation velocities ~ -0.1 dex lower than local reference galaxies at fixed stellar mass.
• By fitting 16 distant comparison samples spanning 0 < z < 3 (containing ~ 1200 galaxies), we show that the size and sign of the inferred Vc offset depends sensitively on the fraction of the parent samples used in the Tully-Fisher analysis, and how strictly the criterion of 'rotation dominated' is enforced.