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Title: Mixing between high velocity clouds and the galactic halo

In the Galactic halo, metal-bearing Galactic halo material mixes into high velocity clouds (HVCs) as they hydrodynamically interact. This interaction begins long before the clouds completely dissipate and long before they slow to the velocity of the Galactic material. In order to make quantitative estimates of the mixing efficiency and resulting metal enrichment of HVCs, we made detailed two- and three-dimensional simulations of cloud-interstellar medium interactions. Our simulations track the hydrodynamics and time-dependent ionization levels. They assume that the cloud originally has a warm temperature and extremely low metallicity while the surrounding medium has a high temperature, low density, and substantial metallicity, but our simulations can be generalized to other choices of initial metallicities. In our simulations, mixing between cloud and halo gas noticeably raises the metallicity of the high velocity material. We present plots of the mixing efficiency and metal enrichment as a function of time.
Authors:
;  [1] ;  [2]
  1. University of Georgia Department of Physics Athens, GA 30602-2451 (Georgia)
  2. School of Natural Science, Ulsan National Institute of Science and Technology (UNIST), 50 UNIST-gil, Ulju-gun, Ulsan 689-798 (Korea, Republic of)
Publication Date:
OSTI Identifier:
22370283
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 795; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; CLOUDS; DENSITY; EFFICIENCY; ENRICHMENT; GALAXIES; GALAXY NUCLEI; HYDRODYNAMICS; INTERACTIONS; IONIZATION; METALLICITY; METALS; MIXING; SIMULATION; THREE-DIMENSIONAL CALCULATIONS; TIME DEPENDENCE; VELOCITY