Kinematic scaling relations of disc galaxies from ionised gas at z  ∼  1 and their connection with dark matter haloes

¹ Leiden Observatory, Leiden University P.O. Box 9513 2300 RA Leiden, The Netherlands
² Dipartimento di Fisica e Astronomia, Università degli Studi di Firenze via G. Sansone 1 50019 Sesto Fiorentino Firenze, Italy
³ Department of Physics and Astronomy, Johns Hopkins University 3400 N. Charles Street Baltimore MD 21218, USA
⁴ INAF – Padova Astronomical Observatory Vicolo dell’Osservatorio 5 I-35122 Padova, Italy
⁵ Sterrenkundig Observatorium, Universiteit Gent Krijgslaan 281 S9 9000 Gent, Belgium

^★ Corresponding author: This email address is being protected from spambots. You need JavaScript enabled to view it.

Received: 22 September 2025
Accepted: 30 November 2025

Abstract

We derive the Tully-Fisher (TFR; M_* − V_circ, f) and Fall (FR; j_* − M_*) relations at redshift z = 0.9 using a sample of 43 main-sequence disc galaxies with Hα IFU data and JWST/HST imaging. The strength of our analysis lies in the use of state-of-the-art 3D kinematic models to infer galaxy rotation curves, the inclusion of near-IR bands and their morphological modelling, and the application of homogeneous spectral energy distribution modelling to our photometry measurements to estimate stellar masses. After correcting the inferred Hα velocities for asymmetric drift, we find a TFR of the form log(M_*/M_⊙) = a log(V_circ,f/ 150 km s⁻¹ + b, with a = 3.82_−0.40^+0.55 and b = 10.27_−0.07^+0.06, as well as a FR of the form log(j_*/kpc km s⁻¹) = alog(M_*/10^10.5 M_⊙)+b, with a = 0.44_−0.06^+0.06 and b = 2.86_−0.02^+0.02. Compared with their z = 0 counterparts, we found moderate evolution in the TFR and strong evolution in the FR over the past 8 Gyr. We interpreted our findings in the context of the galaxy-to-halo scaling parameters f_M = M_*/M_vir and f_j = j_*/j_vir. We inferred that f_j shows little redshift evolution and depends very weakly on M_*, with typical values around f_j ∼ 0.8. As for f_M, we find it to be higher and less dependent on M_* at z = 0.9 than at z = 0. We discuss how interpreting our observed f_M − M_* relations within the cold dark matter framework implies necessarily that the galaxy populations at z = 0.9 and z = 0 are not the progenitor nor descendant of one another. The alternative scenario is that the z = 0.9 scaling relations are incorrect due to strong selection effects, unidentified systematics, or the possibility that Hα kinematics may not be a reliable dynamical tracer. Such problems would affect not only our work but also previous studies on the same subject.