Galaxy Formation

Simulating how galaxies form and evolve across cosmic time

Galaxies grow through a competition between gas accretion, star formation, and feedback, and numerical simulations are our best tool for following that interplay across cosmic time. My group develops and runs cosmological and idealized simulations that follow dark matter, gas, stars, and black holes, with particular attention to how feedback regulates star formation (Iyer et al., 2025).

A major theme of recent work is making the “subgrid” physics of large-volume simulations more predictive by building it on resolved, small-scale calculations: implementing pressure-regulated, feedback-modulated star formation models derived from parsec-scale ISM simulations (Hassan et al., 2024; Burger et al., 2025), and developing the Arkenstone model for capturing fast, hot galactic winds that coarse simulations cannot resolve (Smith et al., 2024; Smith et al., 2024; Sullivan et al., 2026).

We also work closely with observations, for example inferring the intrinsic 3D shapes of high-redshift galaxies seen by JWST (Pandya et al., 2024) and modeling how dust reshapes the ultraviolet and infrared emission of the earliest galaxies (Sommovigo et al., 2026).

References

2026

  1. arXiv
    ArkenstoneBH. A model for high-specific energy black hole feedback in cosmological simulations
    James M. Sullivan, Greg L. Bryan, Matthew C. Smith, and 6 more authors
    arXiv e-prints, May 2026
    DOI arXiv HTML
  2. ApJ
    Blue Monsters and Dusty Descendants: Reconciling UV and IR Emission from Galaxies from z ∼ 7, up to z = 14
    Laura Sommovigo, Lachlan Lancaster, Shyam H. Menon, and 3 more authors
    The Astrophysical Journal, Jun 2026
    DOI arXiv HTML

2025

  1. ApJ
    How Does Feedback Affect the Star Formation Histories of Galaxies?
    Kartheik G. Iyer, Tjitske K. Starkenburg, Greg L. Bryan, and 20 more authors
    The Astrophysical Journal, Dec 2025
    DOI arXiv HTML
  2. MNRAS
    Applying a star formation model calibrated on high-resolution interstellar medium simulations to cosmological simulations of galaxy formation
    Jan D. Burger, Volker Springel, Eve C. Ostriker, and 11 more authors
    Monthly Notices of the Royal Astronomical Society, Dec 2025
    DOI arXiv HTML

2024

  1. ApJ
    Toward Implementation of the Pressure-regulated, Feedback-modulated Model of Star Formation in Cosmological Simulations: Methods and Application to TNG
    Sultan Hassan, Eve C. Ostriker, Chang-Goo Kim, and 12 more authors
    The Astrophysical Journal, Nov 2024
    DOI arXiv HTML
  2. MNRAS
    ARKENSTONE - I. A novel method for robustly capturing high specific energy outflows in cosmological simulations
    Matthew C. Smith, Drummond B. Fielding, Greg L. Bryan, and 11 more authors
    Monthly Notices of the Royal Astronomical Society, Jan 2024
    DOI arXiv HTML
  3. MNRAS
    ARKENSTONE - II. A model for unresolved cool clouds entrained in galactic winds in cosmological simulations
    Matthew C. Smith, Drummond B. Fielding, Greg L. Bryan, and 4 more authors
    Monthly Notices of the Royal Astronomical Society, Dec 2024
    DOI arXiv HTML
  4. ApJ
    Galaxies Going Bananas: Inferring the 3D Geometry of High-redshift Galaxies with JWST-CEERS
    Viraj Pandya, Haowen Zhang, Marc Huertas-Company, and 53 more authors
    The Astrophysical Journal, Mar 2024
    DOI arXiv HTML