2021/01/31 by N. Bouché, Nicolas F. Bouché, Shy Genel +20
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics #Astrophysics and Star Formation Studies #Galaxies: Formation, Evolution, Phenomena #Galaxy #Hubble Deep Field #Hubble Ultra-Deep Field #Physics #Redshift #Star (game theory) #Star formation #Stellar mass #astro-ph.GA
paper · pdf · doi:10.1051/0004-6361/202040225
published as A&A 654, A49 (2021) · 20 pages, 12 figures, accepted version; The TNG50 data is publicly available at https://www.tng-project.org
openalex publication_date 2021/06/30 · openalex created_date 2021/07/05 · arxiv created 2022/01/05 · arxiv updated 2022/01/06 · openalex updated_date 2026/08/06
We investigate the specific angular momentum (sAM) j (< r ) profiles of intermediate redshift (0.4 < z < 1.4) star-forming galaxies (SFGs) in the relatively unexplored regime of low masses (down to M ⋆ ∼ 10 8 M ⊙ ) and small sizes (down to R e ∼ 1.5 kpc), and we characterize the sAM scaling relation (i.e., Fall relation) and its redshift evolution. We have developed a 3D methodology to constrain sAM profiles of the star-forming gas using a forward modeling approach with G A lP A K 3D that incorporates the effects of beam smearing, yielding the intrinsic morpho-kinematic properties even with limited spatial resolution data. Using mock observations from the TNG50 simulation, we find that our 3D methodology robustly recovers the star formation rate (SFR)-weighted j̃ ⋆ ( < r ) profiles down to a low effective signal-to-noise ratio of ⪆3. We applied our methodology blindly to a sample of 494 [O II ]-selected SFGs in the MUSE Ultra Deep Field (UDF) 9 arcmin 2 mosaic data, covering the unexplored 8 < log M ⋆ / M ⊙ < 9 mass range. We find that the (SFR-weighted) sAM relation follows j̃ ⋆ ∝ M ⋆ α with an index α varying from α = 0.3 to α = 0.5, from log M ⋆ / M ⊙ = 8 to log M ⋆ / M ⊙ = 10.5. The UDF sample supports a redshift evolution j̃ ⋆ ∝(1+ z ) a , with a = −0.27 −0.56 +0.42 which is consistent with the (1 + z ) −0.5 expectation from a universe in expansion. The scatter of the sAM sequence is a strong function of the dynamical state with log j | M ⋆ ∝ 0.65 −0.08 +0.06 × log( V max / σ ), where σ is the velocity dispersion at 2 R e . In TNG50, SFGs also form a j̃ ⋆ − M ⋆ −( V / σ ) plane, but it correlates more with galaxy size than with morphological parameters. Our results suggest that SFGs might experience a dynamical transformation, and lose their sAM, before their morphological transformation to becoming passive via either merging or secular evolution.