Validating Semi-analytic Models of High-redshift Galaxy Formation Using Radiation Hydrodynamical Simulations
Year: 2018
Type: article
Abstract: We use a cosmological hydrodynamic simulation calculated with Enzo and the semi-analytic galaxy formation model (SAM) GAMMA to address the chemical evolution of dwarf galaxies in the early universe. The long-term goal of the project is to better understand the origin of metal-poor stars and the formation of dwarf galaxies and the Milky Way halo by cross-validating these theoretical approaches. We combine GAMMA with the merger tree of the most massive galaxy found in the hydrodynamic simulation and compare the star formation rate, the metallicity distribution function (MDF), and the age–metallicity relationship predicted by the two approaches. We found that the SAM can reproduce the global trends of the hydrodynamic simulation. However, there are degeneracies between the model parameters, and more constraints (e.g., star formation efficiency, gas flows) need to be extracted from the simulation to isolate the correct semi-analytic solution. Stochastic processes such as bursty star formation histories and star formation triggered by supernova explosions cannot be reproduced by the current version of GAMMA. Non-uniform mixing in the galaxy’s interstellar medium, coming primarily from self-enrichment by local supernovae, causes a broadening in the MDF that can be emulated in the SAM by convolving its predicted MDF with a Gaussian function having a standard deviation of ∼0.2 dex. We found that the most massive galaxy in the simulation retains nearby 100% of its baryonic mass within its virial radius, which is in agreement with what is needed in GAMMA to reproduce the global trends of the simulation.
Source: The Astrophysical Journal
Authors: Benoit Côté, Devin W. Silvia, Brian W. O’Shea, Britton Smith, John H. Wise
Institutions: Joint Institute for Nuclear Astrophysics, Konkoly Observatory, National Superconducting Cyclotron Laboratory, HUN-REN Research Centre for Astronomy and Earth Sciences, Hungarian Academy of Sciences, Michigan State University, U.S. National Science Foundation, San Diego Supercomputer Center, University of California San Diego, Georgia Institute of Technology
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
Awards: IN THE NEAR FUTURE NEXT-GENERATION TELESCOPES COVERING MOST OF THE ELECTROMAGNETIC SPECTRUM WILL PROVIDE A VIEW INTO THE VERY EARLIEST STAGES OF GALAXY FORMATION. TO ACCURATELY INTERPRET THESE FUTURE OBSERVATIONS ACCURATE AND HIGH-RESOLUTION SIMULATIONS OF THE FIRST STARS AND GALAXIES ARE VITAL. THIS PROPOSAL IS CENTERED ON THE FORMATION OF THE FIRST GALAXIES IN THE UNIVERSE AND THEIR OBSERVATIONAL SIGNATURES IN PREPARATION FOR THESE FUTURE OBSERVATORIES. THIS PROPOSAL HAS TWO OVERALL GOALS: 1. TO SIMULATE THE FORMATION AND EVOLUTION OF A STATISTICALLY SIGNIFICANT SAMPLE OF GALAXIES DURING THE FIRST BILLION YEARS OF THE UNIVERSE INCLUDING ALL RELEVANT ASTROPHYSICS WHILE RESOLVING INDIVIDUAL MOLECULAR CLOUDS IN VARIOUS COSMOLOGICAL ENVIRONMENTS. THESE SIMULATIONS WILL UTILIZE A SOPHISTICATED PHYSICAL MODEL OF STAR AND BLACK HOLE FORMATION AND FEEDBACK INCLUDING RADIATION TRANSPORT AND MAGNETIC FIELDS WHICH WILL LEAD TO THE MOST REALISTIC AND RESOLVED PREDICTIONS FOR THE EARLY UNIVERSE; 2. TO PREDICT THE OBSERVATIONAL FEATURES OF THE FIRST GALAXIES THROUGHOUT THE ELECTROMAGNETIC SPECTRUM ALLOWING FOR OPTIMAL EXTRACTION OF GALAXY AND DARK MATTER HALO PROPERTIES FROM THEIR PHOTOMETRY IMAGING AND SPECTRA; THE PROPOSED RESEARCH PLAN ADDRESSES A TIMELY AND RELEVANT ISSUE TO THEORETICALLY PREPARE FOR THE INTERPRETATION OF FUTURE OBSERVATIONS OF THE FIRST GALAXIES IN THE UNIVERSE. A SUITE OF ADAPTIVE MESH REFINEMENT SIMULATIONS WILL BE USED TO FOLLOW THE FORMATION AND EVOLUTION OF THOUSANDS OF GALAXIES OBSERVABLE WITH THE JAMES WEBB SPACE TELESCOPE (JWST) THAT WILL BE LAUNCHED DURING THE SECOND YEAR OF THIS PROJECT. THE SIMULATIONS WILL HAVE ALSO TRACKED THE FORMATION AND DEATH OF OVER 100 000 MASSIVE METAL-FREE STARS. CURRENTLY THERE IS A GAP OF TWO ORDERS OF MAGNITUDE IN STELLAR MASS BETWEEN THE SMALLEST OBSERVED Z>6 GALAXY AND THE LARGEST SIMULATED GALAXY FROM "FIRST PRINCIPLES" CAPTURING ITS ENTIRE STAR FORMATION HISTORY. THIS PROJECT WILL ELIMINATE THIS GAP BETWEEN SIMULATIONS AND OBSERVATIONS OF THE FIRST GALAXIES PROVIDING PREDICTIONS FOR NEXT-GENERATION OBSERVATIONS COMING ONLINE THROUGHOUT THE NEXT DECADE.THE PROPOSED ACTIVITIES PRESENT THE GRADUATE STUDENTS INVOLVED IN THE PROJECT WITH OPPORTUNITIES TO GAIN EXPERTISE IN NUMERICAL ALGORITHMS HIGH PERFORMANCE COMPUTING AND SOFTWARE ENGINEERING. WITH THIS EXPERIENCE THE STUDENTS WILL BE IN A POWERFUL POSITION TO FACE THE CHALLENGING JOB MARKET. THE COMPUTATIONAL TOOLS PRODUCED BY THIS PROJECT WILL BE MADE FREELY AVAILABLE AND INCORPORATED INTO THEIR RESPECTIVE FRAMEWORKS TO PRESERVE THEIR SUSTAINABILITY., JINA Center for the Evolution of the Elements, Uncovering the Origin and Evolution of Dwarf Galaxies, Collaborative Research: The multi-scale physics of massive black hole formation, fueling and feedback, G4140966627, G425872791, COSMOLOGICAL SIMULATIONS OF GALAXY CLUSTERS TYPICALLY TREAT THE INTRACLUSTER MEDIUM AS A SIMPLE MAGNETIZED FLUID AN APPROXIMATION THAT IS NOW UNDERS, G5579076799, Collaborative Research: CDS&E: Renaissance Simulations Laboratory to Model and Explore the First Galaxies in the Universe, G6533931743, Collaborative research: Multiscale physics and feedback in real and simulated circumgalactic gas over cosmic time
OpenAlex ID: W2766479952