The successful demonstration of the outstanding and world-unique capabilities of ERIS+AO will be transformative in the field. For the first time, fully sampled near-diffraction-limited, high spectral resolution observations of galactic substructure at z~1–3, in particular so-called giant star-forming “clumps”, are possible. Our pioneering first datasets of clumps resolve their internal motions on unprecedented scales down to 500–700 pc spatially and ~10-15 km/s in velocity. Together with resolution-matched JWST imaging, all of the clump kinematics, dynamical masses, star formation rates, outflows, and stellar populations can be determined. These measurements provide much needed quantitative constraints to establish the nature and fate of clumps, and their role in galaxy evolution. Expanding on this breakthrough has high priority for the next ERIS observing campaigns.
Following earlier discovery of fast radial gas flows in a few z~1–3 disk galaxies, motivating one of the GALPHYS goals, the recent findings of stellar bars and spiral arms at those epochs in JWST imaging adds impetus to the project. Previously thought to not be able to form or survive in the gas-rich turbulent high-redshift disks, their presence now suggests they could mediate radial gas flows, and opens up new research avenues for GALPHYS. In parallel, recent numerical simulations can also now produce bar and spiral features in young gas-rich disks, and prove to be an important tool to quantify these instabilities and resulting gas flows at early times; collaborative work with theorists is being intensified. The GALPHYS team is in a unique position to establish direct connections between kinematics from ERIS, NOEMA, and ALMA and stellar structure from JWST to study mass and angular momentum transport, with high anticipated impact.
Based on galaxy-integrated millimeter CO line spectra of 150 typical massive star-forming galaxies at z~0.5–2.5 from the NOEMA precursor, the team found no evidence of cold molecular gas outflow signatures. This result has major implications in future searches for the bulk of mass in galactic outflows at high redshift, and the team initiated follow-up searches via tracers of warmer molecular and neutral gas.
The improvements to ERIS observing strategies and data reduction pipeline, and the release of the DYSMALpy modeling tool with uniquely flexible mass modeling and fitting capabilities, represent significant advances that will benefit the wider astronomical community.
