Scientific Rationale

In the hierarchical ΛCDM cosmological model, galaxies sustain their star formation for extended periods of time in a quasi-steady state of gas inflow, gas outflow, and gas consumption. To first order, the gas that cools at later cosmic epochs has higher angular momentum, therefore it settles in a more extended star-forming disc, implying that galaxies grow from the inside out. However, the actual formation of galaxies in the cosmological context is more complex since a wide range of processes regulate star formation and the orbital distribution of stars, ranging from stellar feedback (supernovae and stellar winds), black hole feedback, and cosmic rays, to galaxy-galaxy interactions and mergers. Therefore, the morphological structure and spatially resolved growth rates of galaxies are a sensitive – but also complicated – probe of galaxy formation physics.

Exactly 100 years after Hubble’s seminal work on the morphology of local galaxies, we will hold a timely conference at KICC to connect the recent, high-redshift JWST discoveries to both predictions from theoretical models and studies of galaxy evolution across cosmic time, down to our own Milky Way galaxy. We want to bring together observers studying the structural evolution of galaxies with theorists and simulators to discuss recent advances in our understanding of the origin of the Hubble Sequence. The main purpose of our conference is to trigger cross discussions between observers and theorists on our current understanding on galaxy morphology, with an emphasis on revisiting the Hubble Sequence in the modern-day galaxy formation framework. 

1. Star Formation and Galaxy Properties along the Hubble Sequence in the Local Universe

• Structural archaeology of nearby galaxies: resolved stellar populations, kinematics, and metallicity gradients in bulges, disks, bars, and spirals.

• Links between present-day star-formation rates, gas fractions, and morphology: all the way from quiescent ellipticals to grand-design spirals.

2. Evolutionary Trends out to Cosmic Noon (z ~ 1-3)

• How gas accretion, mergers, and feedback reshape sizes, bulge-to-disk ratios, and kinematic profiles during the peak epoch of star formation.

• The birth and growth of the first large disks, and the role of violent processes in driving rapid morphological transformation.

3. Emergence of Galaxy Morphology from the Epoch of Reionization to Cosmic Noon 

• JWST and ALMA views of proto-disks, star-forming clumps, and compact spheroids just a few hundred Myr after the Big Bang.

• Dust and gas mapping at high redshift: when do coherent rotation curves first appear, and how do early disks spin up into Milky Way-like structures?

4. Connection of Star Formation, Feedback, and Morphology in the Early Universe

• The physics of clump formation and migration in gas-rich, turbulent disks at z>2: how do feedback and gravitational instability sculpt bulges and thick disks?

• Predictions for the observability of nascent bars, bulges, and dispersion-dominated systems with JWST, ELT, and future facilities.

5. Physics Governing Pathways of Galaxies through Cosmic Time

• Beyond the classic Hubble tuning fork: do simple bulge-disk classifications capture transition objects: compacts, spheroid-dominated disks, or “puffed-up” clumpy systems?

• Integrating observations and theory to constrain how angular momentum, environment, and feedback steer a galaxy’s morphological “track” from the first structures to the present day.

Key Discussion Topics

Important Dates

• 10th Sep 2025 - Abstract submission opens: please submit your abstract here.

• 31st Oct 2025 - Abstract submission deadline

• 1st Dec 2025 - Program release and registration opens

• 31st Jan 2026 - Registration closes