Sergio Martin-Alvarez
Kavli Institute for Particle Astrophysics and Cosmology
KIPAC - Stanford University
Azahar Simulations
Towards physically complete models of galaxy formation to explain observations of galaxies across cosmic time
Azahar is a new series of high-resolution cosmological simulations devoted to capturing both a large population of galaxies and the detail of their internal structures. Our main goal is to determine whether incorporating the physics that we know are important for galaxy formation can provide a replacement to the calibration of sub-grid prescriptions to reproduce galaxy properties and scaling relations.
The Azahar suite, exploring different physics in each of their combinations, is intended to isolate the effects and interplay of different physical processes. The physical completeness of the models also enables a more direct connection to observations through state-of-the-art forward modelling methods, to answer new and old questions of galaxy formation, and in preparation for upcoming multi-wavelength surveys.
Azahar at a glance
-
New physics in the box: Azahar brings magnetohydrodynamics, on-the-fly radiative transfer, and cosmic rays into cosmological galaxy formation. These physics are often omitted or approximated in cosmological simulations, but are fundamental in shaping how galaxies regulate crucial properties such as star formation, winds, and enrichment.
-
A High-resolution cosmological sub-volume: A cosmological box of 25 cMpc with a central region (~10×8×8 cMpc³) resolved down to ~20 physical parsec (full-cell size). In each run, the same physics is applied uniformly across this volume, forming thousands of galaxies per simulated model, to test whether different galaxy formation physics hold for a full population across cosmic time.
-
Pandora heritage: Builds on the Pandora pathfinder project (Martin-Alvarez et al. 2023), which demonstrated how including these non-thermal processes in combination and self-consistently restructures dwarf galaxy formation.
-
Science for JWST and beyond: Our early results are being used to interpret the properties of the first galaxies revealed by JWST, and to prepare for multi-wavelength, spatially resolved diagnostics from the next generation of telescopes (e.g. ngVLA, ELTs).
Visualization 1: zoomed-in views of one of the Azahar large galaxies, forming with standard hydrodynamics (top left), calibrated hydrodynamics (top right), radiative transfer (bottom left) and 'full-physics' (bottom right; radiative transfer, magnetism and cosmic rays).
Galaxies Showcase
Visualization 2: large-scale view showing the inner region of the Azahar zoom. Colours show the cosmic rays (green) and magnetic fields (purple) in one of the 'full-physics' simulations.
Table 1: Suite of simulated models. Columns indicate from left to right the unique symbol and label to identify each simulation, whether the simulation models magnetic fields, whether the model includes on-the-fly radiative transfer, whether it includes cosmic rays, the stellar feedback configuration, and a short set of further details for each simulation. From top to bottom, each run increases in complexity by including additional physics and components.
