The baryonic content and Tully-Fisher relation at z∼0.6

Abstract

Received......; accepted..... Context. Using the multi-integral field spectrograph GIRAFFE at VLT, we have recently derived the stellar-mass Tully-Fisher Relation (smTFR) at z∼0.6 in a representative sample of 63 emission line galaxies. We have found that the distant relation is roughly shifted by a factor two toward smaller masses compared with the local relation. Aims. We extent the study of the evolution of the TFR by establishing the first distant baryonic TFR. We also study further the underlying cause of the large scatter observed in these distant relations. Methods. For deriving gas masses in distant galaxies, we estimate a gas radius and invert the Schmidt-Kennicutt law between star formation rate and gas surface densities. We look at the influence of velocity dispersion on the scatter of the relation, using the kinematic tracer S suggested by Kassin et al. (2007). Results. We find that gas extents farther that UV light from young stars, by∼30 % in median. We present the first baryonic TFR (bTFR) ever established at high redshift and show that, within an uncertainty of±0.08 dex, the bTFR does not appear to evolve in zero point between z∼0.6 and z=0. On the other hand, we confirm that the shift between the local and distant smTFR is found to be very significant, both against random and systematic uncertainties, and that accounting for velocity dispersion leads to a significant decrease of the scatter in the distant relation.