Disk galaxy scaling relations at intermediate redshifts

Abstract

Aims. Galaxy scaling relations such as the Tully-Fisher relation (between the maximum rotation velocity V max and luminosity) and the velocity-size relation (between V max and the disk scale length) are powerful tools to quantify the evolution of disk galaxies with cosmic time. Methods. We took spatially resolved slit spectra of 261 field disk galaxies at redshifts up to z ≈ 1 using the FORS instruments of the ESO Very Large Telescope. The targets were selected from the FORS Deep Field and William Herschel Deep Field. Our spectroscopy was complemented with HST/ACS imaging in the F814W filter. We analyzed the ionized gas kinematics by extracting rotation curves from the two-dimensional spectra. Taking into account all geometrical, observational, and instrumental effects, these rotation curves were used to derive the intrinsic V max .Results. Neglecting galaxies with disturbed kinematics or insufficient spatial rotation curve extent, V max was reliably determined for 124 galaxies covering redshifts 0.05 < z < 0.97. This is one of the largest kinematic samples of distant disk galaxies to date. We compared this data set to the local B-band Tully-Fisher relation and the local velocity-size relation. The scatter in both scaling relations is a factor of ∼2 larger at z ≈ 0.5 than at z ≈ 0. The deviations of individual distant galaxies from the local Tully-Fisher relation are systematic in the sense that the galaxies are increasingly overluminous toward higher redshifts, corresponding to an overluminosity ∆M B = −(1.2 ± 0.5) mag at z = 1. This luminosity evolution at given V max is probably driven by younger stellar populations of distant galaxies with respect to their local counterparts, potentially combined with modest changes in dark matter mass fractions. The analysis of the velocity-size relation reveals that disk galaxies of a given V max have grown in size by a factor of ∼1.5 over the past ∼8 Gyr, most likely through accretion of cold gas and/or small satellites. From scrutinizing the combined evolution in luminosity and size, we find that the galaxies that show the strongest evolution toward smaller sizes at z ≈ 1 are not those that feature the strongest evolution in luminosity, and vice versa.

Galaxy kinematics across different environments in the RXJ1347−1145 cluster complex

“…In all these data sets we note that V max and M B were computed using the same methods presented in this study, which makes them ideal for a direct comparison. The scatter of our cluster sample at z∼0.45 is consistent with what has been previously found in the field (Böhm & Ziegler 2016), while the reported offset in B-band luminosity is larger than that of the Bösch et al (2013b) sample at lower redshift, but in line with what has been found by previous observational studies (Bamford et al 2005) and predictions from semianalytical models (Dutton et al 2011). We repeated our analysis for the M * -TFR ( Fig.…”

“…Black circles represent cluster galaxies at z∼0.2 fromBösch et al (2013b). The solid black line shows the local B-band TFR(Tully et al (1998)) with a 3σ scatter area around reported byBöhm & Ziegler (2016) for galaxies at 0<z<1 (gray area). The orange, blue, and black dashed lines represent the best fit for the cluster and field sample of this study and the cluster sample fromBösch et al (2013b), respectively.…”

Galaxy kinematics in the XMMU J2235-2557 cluster field at z ~ 1.4

“…This evolution is explained by the rise of SFR and the gradual evolution of SP with lookback time. A simple extrapolation of the luminosity evolution linear fit given by Böhm & Ziegler (2016) (gray line) shows that ∆M B = −1.2 ± 0.4 magnitudes at z=1.4. As explained in Figure 3A, our cluster sample can be divided into two groups by their total mass.…”

“…A very important quantitative tool in case of spiral galaxies is the Tully-Fisher relation (TFR), which combines the luminosity of the stellar population (SP) with the characteristic rotational velocity taken as proxy for the total mass (including dark matter). It is well established in the local Universe (Pierce & Tully 1992) and was examined for evolution in recent years out to redshift 1, including work by our own group (Ziegler et al 2003, Böhm et al 2004, Böhm & Ziegler 2007and Böhm & Ziegler 2016.…”

Kinematics of disk galaxies in (proto-)clusters atz= 1.5

“…Hα-based star formation rates versus offsets ∆ M B from the local B-band Tully-Fisher relation. In contrast to field disk galaxies at z < 1 (small open squares; taken fromBöhm & Ziegler 2016), the TFR offsets of the z = 1.47 (proto-)cluster galaxies (filled circles) are not correlated with star formation rate. See text for details.…”