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AR 13904 (Archival Research)

Mon Jul 15 04:26:26 GMT 2024

Principal Investigator: Piero Madau
PI Institution: University of California - Santa Cruz
Investigators (xml)

Title: SIMULATING THE CIRCUMGALACTIC MEDIUM AND THE CYCLE OF BARYONS IN AND OUT OF GALAXIES
Cycle: 22

Abstract
Studies of the ionization, chemical, thermodynamic, and kinematic state of gaseous material in the circumgalactic medium {CGM} hold clues to understanding the exchange of mass, metals, and energy between galaxies and their surroundings. We propose here a detailed comparison of HST-COS data at low redshifts with results from our suite of extreme-resolution cosmological hydrodynamic "zoom-in" simulations of the CGM of massive spiral and sub-L* galaxies. Our state-of-the-art simulations adopt a feedback prescription that produces hundreds of kpc-scale galactic outflows, metal-dependent radiative cooling, and a model for the diffusion of metals and thermal energy. They have been recently shown to generate interstellar absorption line strengths of Lya, CII, CIV, SiII, and SiIV as a function of impact parameter that are in agreement with those observed in the CGM of star-forming massive galaxies, and to reproduce the observed stellar mass and cold gas content, resolved star formation histories, and metallicities of field dwarfs in the Local Volume. During the duration of this program we will: 1} analyze these simulations and trace the formation of the CGM to z=0; 2} add, in post processing, radiative transfer effects using an updated version of the ray-tracing RADAMESH code developed by one of the co-Is; 3} generate synthetic spectra by drawing sightlines through the simulated CGM, and compare the resulting column densities and equivalent widths of key metal ions as a function of impact parameter with data from the Hubble; 4} make the simulated data available online to the community to enhance the value of past, present, and future observational programs with the HST-COS.