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Title: Temperature structure of the intracluster medium from smoothed-particle hydrodynamics and adaptive-mesh refinement simulations

Analyses of cosmological hydrodynamic simulations of galaxy clusters suggest that X-ray masses can be underestimated by 10%-30%. The largest bias originates from both violation of hydrostatic equilibrium (HE) and an additional temperature bias caused by inhomogeneities in the X-ray-emitting intracluster medium (ICM). To elucidate this large dispersion among theoretical predictions, we evaluate the degree of temperature structures in cluster sets simulated either with smoothed-particle hydrodynamics (SPH) or adaptive-mesh refinement (AMR) codes. We find that the SPH simulations produce larger temperature variations connected to the persistence of both substructures and their stripped cold gas. This difference is more evident in nonradiative simulations, whereas it is reduced in the presence of radiative cooling. We also find that the temperature variation in radiative cluster simulations is generally in agreement with that observed in the central regions of clusters. Around R {sub 500} the temperature inhomogeneities of the SPH simulations can generate twice the typical HE mass bias of the AMR sample. We emphasize that a detailed understanding of the physical processes responsible for the complex thermal structure in ICM requires improved resolution and high-sensitivity observations in order to extend the analysis to higher temperature systems and larger cluster-centric radii.
Authors:
 [1] ; ; ;  [2] ;  [3] ;  [4] ; ; ;  [5] ;  [6] ;  [7]
  1. Department of Physics, University of Michigan, 450 Church Street, Ann Arbor, MI 48109 (United States)
  2. Department of Physics, Yale University, New Haven, CT 06520 (United States)
  3. Dipartimento di Fisica dell' Università di Trieste, Sezione di Astronomia, via Tiepolo 11, I-34131 Trieste (Italy)
  4. University Observatory Munich, Scheiner-Str. 1, D-81679 Munich (Germany)
  5. INAF, Osservatorio Astronomico di Trieste, via Tiepolo 11, I-34131, Trieste (Italy)
  6. Dipartimento di Fisica, Università di Roma Tor Vergata, via della Ricerca Scientifica, I-00133, Roma (Italy)
  7. Department of Astronomy, Yale University, New Haven, CT 06520 (United States)
Publication Date:
OSTI Identifier:
22365326
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 791; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; DISPERSIONS; EQUILIBRIUM; FORECASTING; GALAXY CLUSTERS; HYDRODYNAMICS; INTERGALACTIC SPACE; MASS; RADIATIVE COOLING; RESOLUTION; SENSITIVITY; SIMULATION; TEMPERATURE DISTRIBUTION; X RADIATION; X-RAY GALAXIES