Dynamically cold disks in the early Universe: myth or reality?

Understand

Theoretical models struggle to reproduce dynamically cold disks with significant rotation-to-dispersion support($V_{\rm{rot}}/\sigma$) observed in star-forming galaxies in the early Universe, at redshift $z>4$.

• We aim to explore the possible emergence of dynamically cold disks in cosmological simulations and to understand if different kinematic tracers can help reconcile the tension between theory and observations.
• We use 3218 galaxies from the SERRA suite of zoom-in simulations, with $8<\log(M_*/M_{\odot})<10.3$ and SFR$<128\,M_{\odot}{yr}^{-1}$, within $4<z<9$ range.
• We generate hyper-spectral data cubes for 6436 synthetic observations of H$\alpha$ and [CII].