Dissertation

An ALMA view of Galaxies in the Early Universe

This thesis investigates the formation, kinematics, and interstellar medium (ISM) properties of massive galaxies in the early Universe (z~7-14) using sub-millimeter observations from the Atacama Large Millimeter/submillimeter Array (ALMA).

Author

S.T.M. Schouws

Date

01 September 2026

Links

Thesis in Leiden Repository

By probing dust continuum emission in luminous Lyman-break galaxies at z~7-8, this work demonstrates that approximately one-third of their star formation is obscured by dust, favoring steep, supernova-driven attenuation curves. Through targeted [CII]158um blind spectral scans, an efficient method for spectroscopically confirming galaxies in the Epoch of Reionization is established, uncovering substantial kinematic diversity spanning ordered rotating discs, major mergers, and dispersion-dominated systems. Pushing to Cosmic Dawn, the robust detection of [OIII]88um in JADES-GS-z14-0 confirms its spectroscopic redshift at z=14.1793, revealing surprisingly rapid chemical enrichment (Z~0.2-0.5) a mere 300 million years after the Big Bang. Subsequent deep constraints on [CII]158um and dust continuum emission in this galaxy indicate extreme ionization conditions (log U > -2.0), low gas density, and a depleted gas reservoir (f_gas < 0.77), consistent with a system shaped by strong feedback in a dynamic post-outflow phase.

• astronomy
• emission lines
• galactic kinematics
• galaxies
• galaxy evolution
• high-redshift galaxies
• interstellar dust
• interstellar medium
• space