English

Stellar angular momentum of intermediate redshift galaxies in MUSE surveys

Astrophysics of Galaxies 2026-03-24 v2

Abstract

We quantify the stellar rotation of galaxies by computing the λR\lambda_{R} parameter, a proxy for the stellar angular momentum in a sample of 106 galaxies with redshift 0.1 << z << 0.8 and stellar masses from \sim107.5^{7.5} to 1011.8^{11.8} M_{\odot}. The sample is located in the CANDELS/GOODS-S and COSMOS fields, and it was observed by various MUSE surveys. We create stellar velocity and velocity dispersion maps using a full-spectrum fitting technique, covering spatially \sim2ReR_{e} for the galaxies. We study the impact of the atmospheric seeing on the spin parameter and apply corrections when pertinent. Through the analysis of the λRϵ\lambda_{R}-\epsilon diagram, we notice that the fraction of round and massive galaxies increases with redshift. We lack galaxies with λR\lambda_{R} < 0.1 in the sample and we find only one potential, but uncertain, low-mass slow rotator at z 0.3\sim0.3. Moreover, we do not see an evident evolution or trend in the stellar angular momentum with redshift. We characterize the sample environment using two indicators: a local estimator based on the Voronoi tesselation method, and a global estimator derived by the use of the Friends-of-Friends algorithm. We find no correlation between the environment and λR\lambda_{R} given that we are not probing dense regions or massive galaxy structures. We also analyze the kinematic maps of the sample finding that about 40%\% of galaxies are consistent with being regular rotators, having rotating stellar discs with flat velocity dispersion maps, while 20%\sim20\% of galaxies have complex velocity maps and can be identified as non-regular rotators in spite of their λR\lambda_{R} values. For the remaining galaxies the classification is uncertain. As we lack galaxies with λR\lambda_{R}< 0.1, we are not able to identify when galaxies become slow rotators within the surveyed environments, area and redshift range.

Keywords

Cite

@article{arxiv.2404.10533,
  title  = {Stellar angular momentum of intermediate redshift galaxies in MUSE surveys},
  author = {Constanza Muñoz López and Davor Krajnović and B. Epinat and Y. Herrero-Alonso and T. Urrutia and W. Mercier and N. F. Bouché and L. A. Boogaard and T. Contini and L. Michel-Dansac and I. Pessa},
  journal= {arXiv preprint arXiv:2404.10533},
  year   = {2026}
}

Comments

26 pages, 18 figures, Erratum added at the end of the main document