2D Kinematics and physical properties of 1.0 < z < 1.5 star-forming galaxies

TL;DR

This study combines kinematic and morphological data from near-infrared spectroscopy and photometry to analyze the dynamical structures and physical properties of star-forming galaxies at redshifts 1.0 to 1.5, revealing diverse kinematic types and evolutionary states.

Contribution

It provides detailed kinematic classifications and physical characterizations of high-redshift galaxies, including the identification of rotation-dominated disks and their properties, advancing understanding of galaxy evolution.

Findings

Half of the galaxies are rotation-dominated, with some being pure rotational disks.

Maximum velocities of 180-290 km/s are similar to local spirals.

Most galaxies have gas fractions over 50%, indicating ongoing star formation.

Abstract

We combined two-dimensional kinematic and morphology information on the Halpha emission, obtained using near-infrared integral field spectroscopy, with broad-band photometry to investigate the dynamical structure and the physical properties of a sample of ten late-type galaxies at 1.0 < z < 1.5. The sample displays a range of kinematical types which include one merger, one face-on galaxy, and eight objects showing evidence of rotation. Among these eight objects, half are rotation-dominated galaxies, while the rest are dispersion-dominated. We found also that two galaxies out of the rotation-dominated galaxies are pure rotationally supported disks. They achieve a maximum velocity of ~180-290 km/s within ~0.5-1 kpc, similar to local spirals with thin disks. The galaxies of our sample have relatively young stellar populations (< 1.5 Gyr) and possess a range of stellar mass of 0.6-5 X10^10 Msun. In addition, most of them have not yet converted the majority of their gas into stars (six galaxies have their gas fraction >50 per cent). Therefore, those of them which already have a stable disk will probably have their final stellar mass similar to the present-day spirals, to which these rotating systems can be seen as precursors. We conclude our study by investigating the stellar mass Tully-Fisher relation at 1.2 < z < 1.5.