MUSE-ALMA Haloes: bold XV. Cold molecular, ionised, and stellar kinematics of HI-rich galaxies at z ~ 0.5

@article{barfety2026musealma,
  title = {{MUSE-ALMA Haloes: bold XV. Cold molecular, ionised, and stellar kinematics of HI-rich galaxies at z ~ 0.5}},
  author = {C. Barfety and N M Förster Schreiber and C. Péroux and L J Tacconi and J. Chen and S. Weng and V. Bollo and T. O’beirne and M. Zwaan and R. Augustin and B. Casavecchia and L. Chemin and A L Danhaive and N. Guerra-Varas and V. Kulkarni and R. Potlia},
  journal = {Astronomy \& Astrophysics - A\&A},
  year = {2026},
  month = sep,
  doi = {10.1051/0004-6361/202661175},
  url = {https://hal.science/hal-05849775v1},
  note = {CC BY 4.0},
}

TY  - JOUR
TI  - MUSE-ALMA Haloes: bold XV. Cold molecular, ionised, and stellar kinematics of HI-rich galaxies at z ~ 0.5
AU  - C. Barfety
AU  - N M Förster Schreiber
AU  - C. Péroux
AU  - L J Tacconi
AU  - J. Chen
AU  - S. Weng
AU  - V. Bollo
AU  - T. O’beirne
AU  - M. Zwaan
AU  - R. Augustin
AU  - B. Casavecchia
AU  - L. Chemin
AU  - A L Danhaive
AU  - N. Guerra-Varas
AU  - V. Kulkarni
AU  - R. Potlia
PY  - 2026
DA  - 2026/09/30
JO  - Astronomy & Astrophysics - A&A
DO  - 10.1051/0004-6361/202661175
UR  - https://hal.science/hal-05849775v1
AB  - Context. Spatially resolved galaxy kinematics have been most extensively studied at z ∼ 0 and z > 1. The emerging consensus is that disks are common out to z ∼ 3-6, albeit with larger disk velocity dispersions. In this picture, z ∼ 0.5 appears as a key transition in several fundamental aspects, such as the main driver of disk gas turbulence and baryonic-dark matter (DM) mass budget. While at z ∼ 0 multi-tracer spatially resolved characterisation is most readily accessible to study galaxy dynamics, studies with more than one tracer are still sparse for most galaxies outside the local Universe. Aims. We exploited a unique dataset covering spatially resolved cold molecular gas observations with ALMA and spatially resolved ionised gas line emission and stellar continuum with MUSE to study the resolved kinematics of six galaxies at 0.43 < z < 0.83. Obtained as part of the MUSE-ALMA Haloes program and selected by their association with neutral atomic hydrogen (H I) absorption systems, the galaxies span stellar masses from log(M ⋆ /M ⊙ ) = 10.1-11.8. Methods. Using the new ALMA/CO observations and combining them with the existing MUSE ionised gas data and Hubble Space Telescope stellar morphologies, we determined the kinematic nature of the sources by applying morpho-kinematic criteria. For those identified as rotating disks, we employed the forward-modelling parametric kinematic fitting code DYSMALPY to jointly model the Hβ and CO(2-1) observations of the galaxies, and we compared the results to theoretical predictions for pressure support in galaxies. For the stellar kinematics, we used PPXF to fit rest-frame optical stellar absorption features. Results. We find that four of the six galaxies can be classified as disks, and two of these galaxies have previously identified galaxy group members. The four disk galaxies exhibit elevated gas velocity dispersions compared to z ∼ 0 disks, in agreement with the interpolation of observed trends between z ∼ 0 and z > 1. The results are consistent with marginally stable gaseous disks, where gravity-driving still plays a role in addition to stellar feedback, although we find tentative evidence of a differentiation between a dynamically hotter warm phase and the cold gas (σ 0,Hβ ∼ 1.7 × σ 0,CO ). We derived the average DM fraction ⟨ f DM ⟩ = 0.42 ± 0.14, which is consistent with observations at comparable epochs and stellar masses and surface densities. This study highlights the use and completeness of analysing a sample of galaxies in a self-consistent manner and using multi-wavelength observations to explore the physics of disk settling in a relatively less explored redshift range.
SN  - 0004-6361
SN  - 1432-0746
ER  -