TY - JOUR

T1 - Testing galaxy formation simulations with damped Lyman-alpha abundance and metallicity evolution

AU - Hassan, Sultan

AU - Finlator, Kristian

AU - Dave, Romeel

AU - Churchill, Christopher W.

AU - Prochaska, J. Xavier

PY - 2020/2/1

Y1 - 2020/2/1

N2 - We examine the properties of damped Lyman-alpha absorbers (DLAs) emerging from a single set of cosmological initial conditions in two state-of-the-art cosmological hydrodynamic simulations: SIMBA and TECHNICOLOR DAWN. The former includes star formation and black hole feedback treatments that yield a good match with low-redshift galaxy properties, while the latter uses multifrequency radiative transfer to model an inhomogeneous ultraviolet background (UVB) self-consistently and is calibrated to match the Thomson scattering optical depth, UVB amplitude, and Ly alpha forest mean transmission at z > 5. Both simulations are in reasonable agreement with the measured stellar mass and star formation rate functions at z >= 3, and both reproduce the observed neutral hydrogen cosmological mass density, Omega(HI)(z). However, the DLA abundance and metallicity distribution are sensitive to the galactic outflows' feedback and the UVB amplitude. Adopting a strong UVB and/or slow outflows underproduces the observed DLA abundance, but yields broad agreement with the observed DLA metallicity distribution. By contrast, faster outflows eject metals to larger distances, yielding more metal-rich DLAs whose observational selection may be more sensitive to dust bias. The DLA metallicity distribution in models adopting an H-2-regulated star formation recipe includes a tail extending to [M/H]

AB - We examine the properties of damped Lyman-alpha absorbers (DLAs) emerging from a single set of cosmological initial conditions in two state-of-the-art cosmological hydrodynamic simulations: SIMBA and TECHNICOLOR DAWN. The former includes star formation and black hole feedback treatments that yield a good match with low-redshift galaxy properties, while the latter uses multifrequency radiative transfer to model an inhomogeneous ultraviolet background (UVB) self-consistently and is calibrated to match the Thomson scattering optical depth, UVB amplitude, and Ly alpha forest mean transmission at z > 5. Both simulations are in reasonable agreement with the measured stellar mass and star formation rate functions at z >= 3, and both reproduce the observed neutral hydrogen cosmological mass density, Omega(HI)(z). However, the DLA abundance and metallicity distribution are sensitive to the galactic outflows' feedback and the UVB amplitude. Adopting a strong UVB and/or slow outflows underproduces the observed DLA abundance, but yields broad agreement with the observed DLA metallicity distribution. By contrast, faster outflows eject metals to larger distances, yielding more metal-rich DLAs whose observational selection may be more sensitive to dust bias. The DLA metallicity distribution in models adopting an H-2-regulated star formation recipe includes a tail extending to [M/H]

KW - galaxies: evolution

KW - galaxies: formation

KW - intergalactic medium

KW - quasars: absorption lines

KW - cosmology: theory

KW - STAR-FORMATION RATE

KW - LESS-THAN 5

KW - H I

KW - COSMOLOGICAL SIMULATIONS

KW - NEUTRAL HYDROGEN

KW - HIGH-REDSHIFT

KW - ABSORPTION SYSTEMS

KW - BLACK-HOLE

KW - GAS

KW - ABSORBERS

U2 - 10.1093/mnras/staa056

DO - 10.1093/mnras/staa056

M3 - Journal article

VL - 492

SP - 2835

EP - 2846

JO - Royal Astronomical Society. Monthly Notices

JF - Royal Astronomical Society. Monthly Notices

SN - 0035-8711

IS - 2

ER -