TY - JOUR
T1 - Galaxy kinematics and mass estimates at z ∼ 1 from ionised gas and stars
AU - Ubler, Hannah
AU - Schreiber, Natascha M Förster
AU - van der Wel, Arjen
AU - Bezanson, Rachel
AU - Price, Sedona H.
AU - D’Eugenio, Francesco
AU - Wisnioski, Emily
AU - Genzel, Reinhard
AU - Tacconi, Linda J.
AU - Wuyts, Stijn
AU - Naab, Thorsten
AU - Lutz, Dieter
AU - Straatman, Caroline M S
AU - Shimizu, Thomas Taro
AU - Davies, Ric
AU - Liu, Daizhong
AU - Mendel, J Trevor
PY - 2024/1/31
Y1 - 2024/1/31
N2 - We compare ionised gas and stellar kinematics of 16 star-forming galaxies (log (M⋆/M⊙) = 9.7 − 11.2, SFR =6 − 86M⊙/yr) at z ∼ 1 using near-infrared integral field spectroscopy (IFS) of Hα emission from the KMOS3D survey and optical slit spectroscopy of stellar absorption and gas emission from the LEGA-C survey. Hα is dynamically colder than stars, with higher disc rotation velocities (by ∼45 per cent) and lower disc velocity dispersions (by a factor ∼2). This is similar to trends observed in the local Universe. We find higher rotational support for Hα relative to [OII], potentially explaining systematic offsets in kinematic scaling relations found in the literature. Regarding dynamical mass measurements, for six galaxies with cumulative mass profiles from Jeans Anisotropic Multi-Gaussian Expansion (JAM) models the Hα dynamical mass models agree remarkably well out to ∼10 kpc for all but one galaxy (average ΔΜdyn(Re, F814W) < 0.1 dex). Simpler dynamical mass estimates based on integrated stellar velocity dispersion are less accurate (standard deviation 0.24 dex). Differences in dynamical mass estimates are larger, for example, for galaxies with stronger misalignments of the Hα kinematic major axis and the photometric position angle, highlighting the added value of IFS observations for dynamics studies. The good agreement between the JAM models and the dynamical models based on Hα kinematics at z ∼ 1 corroborates the validity of dynamical mass measurements from Hα IFS observations, which can be more easily obtained for higher redshift galaxies.
AB - We compare ionised gas and stellar kinematics of 16 star-forming galaxies (log (M⋆/M⊙) = 9.7 − 11.2, SFR =6 − 86M⊙/yr) at z ∼ 1 using near-infrared integral field spectroscopy (IFS) of Hα emission from the KMOS3D survey and optical slit spectroscopy of stellar absorption and gas emission from the LEGA-C survey. Hα is dynamically colder than stars, with higher disc rotation velocities (by ∼45 per cent) and lower disc velocity dispersions (by a factor ∼2). This is similar to trends observed in the local Universe. We find higher rotational support for Hα relative to [OII], potentially explaining systematic offsets in kinematic scaling relations found in the literature. Regarding dynamical mass measurements, for six galaxies with cumulative mass profiles from Jeans Anisotropic Multi-Gaussian Expansion (JAM) models the Hα dynamical mass models agree remarkably well out to ∼10 kpc for all but one galaxy (average ΔΜdyn(Re, F814W) < 0.1 dex). Simpler dynamical mass estimates based on integrated stellar velocity dispersion are less accurate (standard deviation 0.24 dex). Differences in dynamical mass estimates are larger, for example, for galaxies with stronger misalignments of the Hα kinematic major axis and the photometric position angle, highlighting the added value of IFS observations for dynamics studies. The good agreement between the JAM models and the dynamical models based on Hα kinematics at z ∼ 1 corroborates the validity of dynamical mass measurements from Hα IFS observations, which can be more easily obtained for higher redshift galaxies.
U2 - 10.1093/mnras/stad3826
DO - 10.1093/mnras/stad3826
M3 - Article
SN - 0035-8711
VL - 527
SP - 9206
EP - 9235
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
IS - 3
ER -