The turbulent life of dust grains in the supernova-driven, multiphase interstellar medium

• Verfasst von: Peters, Thomas [VerfasserIn]
• Verfasst von: Glover, Simon [VerfasserIn]
• Verfasst von: Klessen, Ralf S. [VerfasserIn]
• Titel: The turbulent life of dust grains in the supernova-driven, multiphase interstellar medium
• Verf.angabe: Thomas Peters, Svitlana Zhukovska, Thorsten Naab, Philipp Girichidis, Stefanie Walch, Simon C.O. Glover, Ralf S. Klessen, Paul C. Clark and Daniel Seifried
• Umfang: 21 S.
• Fussnoten: Gesehen am 23.10.2017
• Titel Quelle: Enthalten in: Royal Astronomical Society: Monthly notices of the Royal Astronomical Society
• Jahr Quelle: 2017
• Band/Heft Quelle: 467(2017), 4, S. 4322-4342
• ISSN Quelle: 1365-2966
• DOI: doi:10.1093/mnras/stx341
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1564642801

Abstract

Dust grains are an important component of the interstellar medium (ISM) of galaxies. We present the first direct measurement of the residence times of interstellar dust in the different ISM phases, and of the transition rates between these phases, in realistic hydrodynamical simulations of the multiphase ISM. Our simulations include a time-dependent chemical network that follows the abundances of H+, H, H2, C+ and CO and take into account self-shielding by gas and dust using a tree-based radiation transfer method. Supernova explosions are injected either at random locations, at density peaks, or as a mixture of the two. For each simulation, we investigate how matter circulates between the ISM phases and find more sizeable transitions than considered in simple mass exchange schemes in the literature. The derived residence times in the ISM phases are characterized by broad distributions, in particular for the molecular, warm and hot medium. The most realistic simulations with random and mixed driving have median residence times in the molecular, cold, warm and hot phase around 17, 7, 44 and 1 Myr, respectively. The transition rates measured in the random driving run are in good agreement with observations of Ti gas-phase depletion in the warm and cold phases in a simple depletion model. ISM phase definitions based on chemical abundance rather than temperature cuts are physically more meaningful, but lead to significantly different transition rates and residence times because there is no direct correspondence between the two definitions.