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Full-Text Articles in Physical Sciences and Mathematics
Metal Enrichment Of The Intergalactic Medium In Cosmological Simulations, A Aguirre, L Hernquist, J Schaye, N Katz, Dh Weinberg, J Gardner
Metal Enrichment Of The Intergalactic Medium In Cosmological Simulations, A Aguirre, L Hernquist, J Schaye, N Katz, Dh Weinberg, J Gardner
Astronomy Department Faculty Publication Series
Observations have established that the diffuse intergalactic medium (IGM) at z ~ 3 is enriched to ~10-2.5 solar metallicity and that the hot gas in large clusters of galaxies (ICM) is enriched to - Z at z = 0. Metals in the IGM may have been removed from galaxies (in which they presumably form) during dynamical encounters between galaxies, by ram-pressure stripping, by supernova-driven winds, or as radiation-pressure-driven dust efflux. This study develops a method of investigating the chemical enrichment of the IGM and of galaxies, using already completed cosmological simulations. To these simulations we add dust and (gaseous) …
Enrichment Of The Intergalactic Medium By Radiation Pressure-Driven Dust Efflux, A Aguirre, L Hernquist, N Katz, J Gardner, D Weinberg
Enrichment Of The Intergalactic Medium By Radiation Pressure-Driven Dust Efflux, A Aguirre, L Hernquist, N Katz, J Gardner, D Weinberg
Astronomy Department Faculty Publication Series
The presence of metals in hot cluster gas and in Lyα absorbers, as well as the mass-metallicity relation of observed galaxies, suggest that galaxies lose a significant fraction of their metals to the intergalactic medium (IGM). Theoretical studies of this process have concentrated on metal removal by dynamical processes or supernova-driven winds. Here we investigate the enrichment of the IGM by the expulsion of dust grains from galaxies by radiation pressure. We use already completed cosmological simulations to which we add dust, assuming that most dust can reach the equilibrium point between radiation pressure and gravitational forces. We find that …
Baryons In The Warm-Hot Intergalactic Medium, R Dave, R Cen, Jp Ostriker, Gl Bryan, L Hernquist, N Katz, Dh Weinberg, Ml Norman, B O'Shea
Baryons In The Warm-Hot Intergalactic Medium, R Dave, R Cen, Jp Ostriker, Gl Bryan, L Hernquist, N Katz, Dh Weinberg, Ml Norman, B O'Shea
Astronomy Department Faculty Publication Series
Approximately 30%-40% of all baryons in the present-day universe reside in a warm-hot intergalactic medium (WHIM), with temperatures in the range 105 < T < 107 K. This is a generic prediction from six hydrodynamic simulations of currently favored structure formation models having a wide variety of numerical methods, input physics, volumes, and spatial resolutions. Most of these warm-hot baryons reside in diffuse large-scale structures with a median overdensity around 10-30, not in virialized objects such as galaxy groups or galactic halos. The evolution of the WHIM is primarily driven by shock heating from gravitational perturbations breaking on mildly nonlinear, nonequilibrium …