Massive Stars as Cosmic Clocks
Shaping the evolution of infant galaxies
How massive stars shape the first galaxies
The earliest galaxies are dominated by young stellar populations, and massive stars act as their “cosmic clocks” during the first tens of millions of years of star formation. Their radiation shapes what we observe; stellar winds and supernovae inject energy into the interstellar medium; and the elements and dust they produce drive chemical enrichment. Their remnants may also form black-hole seeds. This project combines state-of-the-art stellar models, galaxy-evolution tools and cosmological simulations to investigate how the mass, metallicity and rotation of massive stars influence the assembly and observable properties of infant galaxies.
Four connected objectives
Determine which massive stars explode and enrich the interstellar medium, what elemental abundances they produce, and how initial stellar mass relates to final black-hole mass.
Understand the timescales of mechanical and chemical feedback in the first galaxies.
Explore the statistical properties of the first galaxies and active galactic nuclei (AGNs).
Investigate how dust is produced and enriches the first galaxies.
Four work packages
From stellar birth to remnant
Extend presupernova model grids across initial masses of 13–120 M☉, metallicities from zero to 2 Z☉, and rotation velocities of 0, 150 and 300 km/s. Calculate explosions, nucleosynthetic yields and final neutron-star or black-hole masses.
Track feedback and observables
Use simplified galaxy-evolution models and a redshift- and metallicity-dependent stellar initial mass function to explore star-formation histories, ultraviolet luminosities, chemical abundances and black-hole populations. Predict spectra for comparison with JWST observations.
Explore the high-redshift population
Use the CAT semi-analytical model with the new stellar grids and feedback prescriptions to study the statistical properties of galaxies and AGNs, their star-formation history and black-hole seed populations at high redshift.
Follow dust and metals in detail
Update cosmological hydrodynamical zoom-in simulations with new stellar yields, supernova dust production and feedback to investigate the enrichment histories of the first star-forming galaxies.
Project team
Marco Limongi
Principal Investigator; FRANEC stellar models and HYPERION explosions, nucleosynthesis and remnants.
Alessandro Chieffi
FRANEC presupernova models and nucleosynthesis; HYPERION explosions and yields.
Lorenzo Roberti
Massive-star models, nucleosynthesis and explosion calculations.
Cristiano Ugolini
HYPERION explosion calculations, yields and remnant masses.
Raffaella Schneider
Galaxy toy models and implications for high-redshift galaxy evolution.
Rosa Valiante
CAT semi-analytical modelling and galaxy and AGN predictions.
Alessandro Trinca
CAT implementation and statistical properties of galaxies and AGNs.
Luca Graziani
Hydrodynamical models, cosmic enrichment and dust yields.
Federico Angeloni
Dusty-galaxy simulations and chemical evolution.
Alessandra Venditti
Cosmological simulations and chemical evolution of dust.
Roles are summarized from the project proposal; participants and work-package assignments are those listed in the attached document.
Project details are summarized from the INAF project proposal (PDF) and the CV. The proposal describes planned research and deliverables.