The evolution of the Tully-Fisher relation of spiral galaxies

We present the B-band Tully-Fisher relation (TFR) of 60 late-type galaxies with redshifts 0.1-1. The galaxies were selected from the FORS Deep Field with a limiting magnitude of R=23. Spatially resolved rotation curves were derived from spectra obtained with FORS2 at the VLT. High-mass galaxies with v_max>=150 km/s show little evolution, whereas the least massive systems in our sample are brighter by about 1-2 mag compared to their local counterparts. For the entire distant sample, the TFR slope is flatter than for local field galaxies (-5.77+-0.45 versus -7.92+-0.18). Thus, we find evidence for evolution of the slope of the TFR with redshift on the 3-sigma level. This is still true when we subdivide the sample into three redshift bins. We speculate that the flatter tilt of our sample is caused by the evolution of luminosities and an additional population of blue galaxies at z>=0.2. The mass dependence of the TFR evolution also leads to variations for different galaxy types in magnitude-limited samples, suggesting that selection effects can account for the discrepant results of previous TFR studies on the luminosity evolution of late-type galaxies.