Stellar Dynamical Models for 797 z ∼ 0.8 Galaxies from LEGA-C
Journal
Astrophysical Journal
Journal Volume
923
Journal Issue
1
Date Issued
2021
Author(s)
Van Houdt J
Van Der Wel A
Bezanson R
Franx M
D'Eugenio F
Barisic I
Bell E.F
Gallazzi A
De Graaff A
Maseda M.V
Pacifici C
Van De Sande J
Sobral D
Straatman C
Abstract
We present spatially resolved stellar kinematics for 797 z = 0.6-1 galaxies selected from the LEGA-C survey and construct axisymmetric Jeans models to quantify their dynamical mass and degree of rotational support. The survey is K s -band selected, irrespective of color or morphological type, and allows for a first assessment of the stellar dynamical structure of the general L∗ galaxy population at large look-back time. Using light profiles from Hubble Space Telescope imaging as a tracer, our approach corrects for observational effects (seeing convolution and slit geometry), and uses well-informed priors on inclination, anisotropy, and a non-luminous mass component. Tabulated data include total mass estimates in a series of spherical apertures (1, 5, and 10 kpc; 1 × and 2 × R e), as well as rotational velocities, velocity dispersions, and anisotropy. We show that almost all star-forming galaxies and ∼50% of quiescent galaxies are rotation dominated, with deprojected V/σ ∼ 1-2. Revealing the complexity in galaxy evolution, we find that the most massive star-forming galaxies are among the most rotation dominated, and the most massive quiescent galaxies among the least rotation-dominated galaxies. These measurements set a new benchmark for studying galaxy evolution, using stellar dynamical structure for galaxies at large look-back time. Together with the additional information on stellar population properties from the LEGA-C spectra, the dynamical mass and V/σ measurements presented here create new avenues for studying galaxy evolution at large look-back time. © 2021. The American Astronomical Society. All rights reserved..
Type
journal article