2017/01/01 by Adrien Guérou, Adrien Guerou, Davor Krajnović +19 · 32 citations
Physics and Astronomy · #Adaptive optics and wavefront sensing #Astronomy #Astronomy and Astrophysical Research #Astrophysics #Astrophysics and Star Formation Studies #Elliptical galaxy #Galaxies: Formation, Evolution, Phenomena #Galaxy #Galaxy formation and evolution #Hubble Deep Field #Hubble Deep Field South #Hubble Ultra-Deep Field #Milky Way #Physics #Redshift #Star formation #Stellar kinematics #Stellar mass #Velocity dispersion #astro-ph.GA
paper · pdf · doi:10.1051/0004-6361/201730905
published in Leiden Repository (Leiden University) 608, A5 (Leiden University) · 25 pages, 27 figures, A&A for accepted (26 June 2017)
openalex publication_date 2017/01/01 · arxiv created 2017/10/20 · arxiv updated 2017/12/13 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We present spatially resolved stellar kinematic maps, for the first time, for a sample of 17 intermediate redshift galaxies (0.2 ≲ <i>z<i/> ≲ 0.8). We used deep MUSE/VLT integral field spectroscopic observations in the <i>Hubble <i/>Deep Field South (HDFS) and <i>Hubble <i/>Ultra Deep Field (HUDF), resulting from ≈30 h integration time per field, each covering 1′ × 1′ field of view, with ≈ 0.̋65 spatial resolution. We selected all galaxies brighter than 25 mag in the <i>I<i/> band and for which the stellar continuum is detected over an area that is at least two times larger than the spatial resolution. The resulting sample contains mostly late-type disk, main-sequence star-forming galaxies with 10<sup>8.5<sup/> <i>M<i/><sub>⊙<sub/> ≲ <i>M<i/><sub>∗<sub/> ≲ 10<sup>10.5<sup/> <i>M<i/><sub>⊙<sub/>. Using a full-spectrum fitting technique, we derive two-dimensional maps of the stellar and gas kinematics, including the radial velocity <i>V<i/> and velocity dispersion <i>σ<i/>. We find that most galaxies in the sample are consistent with having rotating stellar disks with roughly constant velocity dispersions and that the second order velocity moments <i>V<i/><sub>rms<sub/> = √<i>V<i/><sup>2<sup/>+<i>σ<i/><sup>2<sup/> of the gas and stars, a scaling proxy for the galaxy gravitational potential, compare well to each other. These spatially resolved observations of the stellar kinematics of intermediate redshift galaxies suggest that the <i>regular <i/>stellar kinematics of disk galaxies that is observed in the local Universe was already in place 4–7 Gyr ago and that their gas kinematics traces the gravitational potential of the galaxy, thus is not dominated by shocks and turbulent motions. Finally, we build dynamical axisymmetric Jeans models constrained by the derived stellar kinematics for two specific galaxies and derive their dynamical masses. These are in good agreement (within 25%) with those derived from simple exponential disk models based on the gas kinematics. The obtained mass-to-light ratios hint towards dark matter dominated systems within a few effective radii.