Spatially resolved stellar kinematics from LEGA-C : increased rotational support in z ∼ 0.8 quiescent galaxies

We present stellar rotation curves and velocity dispersion profiles for 104 quiescent galaxies at z = 0.6-1 from the Large Early Galaxy Astrophysics Census (LEGA-C) spectroscopic survey. Rotation is typically probed across 10-20 kpc, or to an average of 2.7R(e). Combined with central stellar velocit...

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Bibliographic Details
Published in:The Astrophysical Journal
Main Authors: Bezanson, Rachel, van der Wel, Arjen, Pacifici, Camilla, Noeske, Kai, Barišić, Ivana, Bell, Eric F, Brammer, Gabriel B, Calhau, Joao, Chauke, Priscilla, van Dokkum, Pieter, Franx, Marijn, Gallazzi, Anna, van Houdt, Josha, Labbé, Ivo, Maseda, Michael V, Muños-Mateos, Juan Carlos, Muzzin, Adam, van de Sande, Jesse, Sobral, David, Straatman, Caroline, Wu, Po-Feng
Format: Article in Journal/Newspaper
Language:English
Published: 2018
Subjects:
Physics and Astronomy
galaxies
elliptical and lenticular
cD - galaxies
evolution - galaxies
high-redshift - galaxies
kinematics and dynamics - galaxies
structure
HUBBLE-SPACE-TELESCOPE
TULLY-FISHER RELATION
SUPERDENSE MASSIVE GALAXIES
STAR-FORMING GALAXIES
INSIDE-OUT GROWTH
INFRARED SPECTROSCOPIC SURVEY
HIGH-REDSHIFT GALAXIES
K-SELECTED GALAXIES
SAMI PILOT SURVEY
ELLIPTIC GALAXIES
Hubble
sami
Online Access:https://biblio.ugent.be/publication/8562684
http://hdl.handle.net/1854/LU-8562684
https://doi.org/10.3847/1538-4357/aabc55
https://biblio.ugent.be/publication/8562684/file/8580333
Description
Summary:We present stellar rotation curves and velocity dispersion profiles for 104 quiescent galaxies at z = 0.6-1 from the Large Early Galaxy Astrophysics Census (LEGA-C) spectroscopic survey. Rotation is typically probed across 10-20 kpc, or to an average of 2.7R(e). Combined with central stellar velocity dispersions (sigma(0)) this provides the first determination of the dynamical state of a sample selected by a lack of star formation activity at large lookback time. The most massive galaxies (M-star > 2 x 10(11) M-circle dot) generally show no or little rotation measured at 5 kpc (vertical bar V-5 vertical bar /sigma(0) < 0.2 in eight of ten cases), while similar to 64% of less massive galaxies show significant rotation. This is reminiscent of local fast-and slow-rotating ellipticals and implies that low-and high-redshift quiescent galaxies have qualitatively similar dynamical structures. We compare vertical bar V-5 vertical bar sigma(0) distributions at z similar to 0.8 and the present day by re-binning and smoothing the kinematic maps of 91 low-redshift quiescent galaxies from the Calar Alto Legacy Integral Field Area (CALIFA) survey and find evidence for a decrease in rotational support since z similar to 1. This result is especially strong when galaxies are compared at fixed velocity dispersion; if velocity dispersion does not evolve for individual galaxies then the rotational velocity at 5 kpc was an average of 94 +/- 22% higher in z similar to 0.8 quiescent galaxies than today. Considering that the number of quiescent galaxies grows with time and that new additions to the population descend from rotationally supported star-forming galaxies, our results imply that quiescent galaxies must lose angular momentum between z similar to 1 and the present, presumably through dissipationless merging, and/or that the mechanism that transforms star-forming galaxies also reduces their rotational support.

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