The "Feedback in Realistic Environments" (FIRE) project introduces exciting new ways to account for the effects of the earliest generation of stars, formed when the Universe is young, on the formation of galaxies and clusters of galaxies, the large-scale tracers of cosmology, the science of the origin and evolution of the Universe. The FIRE computer models will include more of the important physics than has ever been done before, and early tests suggest this work agrees with observations more cleanly than previous studies, which had to include various arbitrary assumptions in order to make progress. The technical details within FIRE will also disentangle problems due to the uncertain physics of galaxy formation from problems caused solely by the limitations of computer modeling.
FIRE will carry out novel computational studies of galaxy formation using high-resolution cosmological simulations that resolve the interstellar medium (ISM) with unprecedented realism. Star formation injects large quantities of energy and momentum into the surrounding medium, and this stellar feedback generates galactic winds that affect the galactic environment. This project will run the first cosmological simulations that self-consistently include important stellar feedback physics. Combining a resolved, multiphase ISM with highly non-linear feedback interactions produces powerful galactic winds in broad agreement with observations, without using any of the ad hoc prescriptions which previous simulations have had to invoke. FIRE simulations will address the regulation of galaxy growth by stellar feedback, the properties of galactic inflows and outflows, the morphological transformation of galaxies, quenching of star formation in massive galaxies, active galactic nucleus feedback, the escape fraction of ionizing photons, and stellar feedback on dark matter halos. All of these simulations will be connected directly with multi-wavelength observations. In particular, simulated absorption line statistics compared with high-redshift measurements will test predictions of gas flows in and out of galaxies. Technical enhancements incorporated into FIRE will help to quantify the relative importance of numerical and physical uncertainties in galaxy formation modeling. The initial conditions of all FIRE simulations will be made available to the community to motivate others to follow this approach.
The project includes training of four graduate students, who will also learn from the collaborative interactions across three institutions. Visualizations from FIRE form a basis for outreach targeted at high school students, including workshops in computational thinking for teachers. Other efforts include seminars aimed at teachers, local astronomy enthusiasts, and students from underrepresented groups, working to explain the connection between local phenomena on Earth and the cosmic processes studied by FIRE.
