The Tully-Fisher relation in dense groups at z ∼ 0.7 in the MAGIC survey

Abstract

Context. Galaxies in dense environments are subject to interactions and mechanisms that directly affect their evolution by lowering their gas fractions and consequently reducing their star-forming capacity earlier than their isolated counterparts. Aims. The aim of our project is to get new insights into the role of environment in the stellar and baryonic content of galaxies using a kinematic approach, through the study of the Tully-Fisher relation (TFR). Methods. We study a sample of galaxies in eight groups, over-dense by a factor larger than 25 with respect to the average projected density, spanning a redshift range of 0.5 < z < 0.8 and located in ten pointings of the MAGIC MUSE Guaranteed Time Observations program. We perform a morpho-kinematics analysis of this sample and set up a selection based on galaxy size, [O II]λλ3727,3729 emission line doublet signal-to-noise ratio, bulge-to-disk ratio, and nuclear activity to construct a robust kinematic sample of 67 star-forming galaxies. Results. We show that this selection considerably reduces the number of outliers in the TFR, which are predominantly dispersion-dominated galaxies. Similar to other studies, we find that including the velocity dispersion in the velocity budget mainly affects galaxies with low rotation velocities, reduces the scatter in the relation, increases its slope, and decreases its zero-point. Including gas masses is more significant for low-mass galaxies due to a larger gas fraction, and thus decreases the slope and increases the zero-point of the relation. Our results suggest a significant offset of the TFR zero-point between galaxies in low- and high-density environments, regardless of the kinematics estimator used. This can be interpreted as a decrease in either stellar mass by ∼0.05 − 0.3 dex or an increase in rotation velocity by ∼0.02 − 0.06 dex for galaxies in groups, depending on the samples used for comparison. We also studied the stellar and baryon mass fractions within stellar disks and found they both increase with stellar mass, the trend being more pronounced for the stellar component alone. These fractions do not exceed 50%. We show that this evolution of the TFR is consistent either with a decrease in star formation or with a contraction of the mass distribution due to the environment. These two effects probably act together, with their relative contribution depending on the mass regime.

The MUSE Extremely Deep Field: Evidence for SFR-induced cores in dark-matter dominated galaxies atz≃ 1

“…More specifically, the TFR has M = a V n tot,2.2 with n 4, a 10 10 M (McGaugh 2005; Meyer et al 2008;Cresci et al 2009;Pelliccia et al 2017;Tiley et al 2016;Übler et al 2017;Abril-Melgarejo et al 2021) where V rot,2.2 ≡ V rot /10 2.2 km s −1 . Given that V 2 max, ≡ 0.38 GM R d for a Freeman (1970)…”

“…Exploring lower mass SFGs, this exercise requires a stacking approach (as in Lang et al 2017;Tiley et al 2019) or deep IFS observations (as in Genzel et al 2020). These studies of massive SFGs with M > 10 11 M showed that RCs are declining at large radii, indicative of a low DM fraction within R e ; see also Wuyts et al (2016), Übler et al (2017), Abril-Melgarejo et al (2021) for dynamical estimates of DM fractions.…”

The MUSE Extremely Deep Field: a first panoramic view of an Mg II emitting intragroup medium

“…The first detection of a large ionized structure in a galaxy group was reported by Epinat et al (2018). Using MUSE, they found a 150 kpc large [O ii] nebula at z 0.7 embracing a dozen of galaxies with maximum stellar masses of ≈10 10.9 M (the DM halo mass of the group is 6.5×10 13 M , see Abril-Melgarejo et al 2021). By investigating the kinematics and ionisation properties, the authors concluded that gas was stripped out of the galaxies by tidal forces after galaxy interactions and AGN outflow.…”

The MUSE Extremely Deep Field: Evidence for SFR-induced cores in dark-matter dominated galaxies at z=1

“…More specifically, the TFR has M = a V n tot,2.2 with n 4, a 10 10 M (McGaugh 2005;Meyer et al 2008;Cresci et al 2009;Pelliccia et al 2017;Tiley et al 2016;Übler et al 2017;Abril-Melgarejo et al 2021) where V rot,2.2 ≡ V rot /10 2.2 km/s. Given that V 2 max,…”

“…Exploring lower mass SFGs, this exercise requires a stacking approach (as in Lang et al 2017;Tiley et al 2019) or deep IFS observations (as in Genzel et al 2020). These studies of massive SFGs with M > 10 11 M showed that RCs are declining at large radii, indicative of a low DM fraction within R e ; see also Wuyts et al (2016); Übler et al (2017); Abril-Melgarejo et al (2021) for dynamical estimates of DM fractions.…”