Turbulence driven by structure formation in the circumgalactic medium

• Verfasst von: Iapichino, Luigi [VerfasserIn]
• Verfasst von: Viel, Matteo [VerfasserIn]
• Verfasst von: Borgani, Stefano [VerfasserIn]
• Titel: Turbulence driven by structure formation in the circumgalactic medium
• Verf.angabe: L. Iapichino, M. Viel and S. Borgani
• E-Jahr: 2013
• Jahr: 2013 May 1
• Umfang: 12 S.
• Fussnoten: Gesehen am 07.12.2021
• Titel Quelle: Enthalten in: Royal Astronomical SocietyMonthly notices of the Royal Astronomical Society
• Ort Quelle: Oxford : Oxford Univ. Press, 1827
• Jahr Quelle: 2013
• Band/Heft Quelle: 432(2013), 3, Seite 2529-2540
• ISSN Quelle: 1365-2966
• DOI: doi:10.1093/mnras/stt611
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 178052403X

Abstract

The injection of turbulence in the circumgalactic medium at redshift z = 2 is investigated using the mesh-based hydrodynamic code enzo and a sub-grid-scale (SGS) model for unresolved turbulence. Radiative cooling and heating by a uniform Ultraviolet (UV) background are included in our runs and compared with the effect of turbulence modelling. Mechanisms of gas exchange between galaxies and the surrounding medium, as well as metal enrichment, are not taken into account, and turbulence is here driven solely by structure formation (mergers and shocks). We find that turbulence, both at resolved and SGS scales, impacts mostly the warm-hot intergalactic medium (WHIM), with temperature between 105 and 107 K, mainly located around collapsed and shock-heated structures, and in filaments. Typical values of the ratio of turbulent to thermal pressure is 0.1 in the WHIM, corresponding to a volume-weighted average of the SGS turbulent to thermal Doppler broadening bt/btherm = 0.26, on length scales below the grid resolution of 25 kpc h− 1. In the diffuse intergalactic medium, defined in a range of baryon overdensity δ between 1 and 50, the importance of turbulence is smaller, but grows as a function of gas density, and the Doppler broadening ratio is fitted by the function bt/btherm = 0.023 × δ0.58.