Modelling the supernova-driven ISM in different environments

• Verfasst von: Gatto, Andrea [VerfasserIn]
• Verfasst von: Glover, Simon [VerfasserIn]
• Verfasst von: Klessen, Ralf S. [VerfasserIn]
• Verfasst von: Clark, Paul C. [VerfasserIn]
• Verfasst von: Baczynski, Christian [VerfasserIn]
• Titel: Modelling the supernova-driven ISM in different environments
• Verf.angabe: A. Gatto, S. Walch, M.-M. Mac Low, T. Naab, P. Girichidis, S.C.O. Glover, R. Wünsch, R.S. Klessen, P.C. Clark, C. Baczynski, T. Peters, J.P. Ostriker, J.C. Ibáñez-Mejía and S. Haid
• E-Jahr: 2015
• Jahr: 20 March 2015
• Umfang: 19 S.
• Fussnoten: Gesehen am 09.08.2021
• Titel Quelle: Enthalten in: Royal Astronomical SocietyMonthly notices of the Royal Astronomical Society
• Ort Quelle: Oxford : Oxford Univ. Press, 1827
• Jahr Quelle: 2015
• Band/Heft Quelle: 449(2015), 1, Seite 1057-1075
• ISSN Quelle: 1365-2966
• DOI: doi:10.1093/mnras/stv324
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1765956307

Abstract

We use hydrodynamical simulations in a (256 pc)3 periodic box to model the impact of supernova (SN) explosions on the multiphase interstellar medium (ISM) for initial densities n = 0.5-30 cm−3 and SN rates 1-720 Myr−1. We include radiative cooling, diffuse heating, and the formation of molecular gas using a chemical network. The SNe explode either at random positions, at density peaks, or both. We further present a model combining thermal energy for resolved and momentum input for unresolved SNe. Random driving at high SN rates results in hot gas (T ≳ 106 K) filling >90 per cent of the volume. This gas reaches high pressures (104 < P/kB < 107 K cm−3) due to the combination of SN explosions in the hot, low-density medium and confinement in the periodic box. These pressures move the gas from a two-phase equilibrium to the single-phase, cold branch of the cooling curve. The molecular hydrogen dominates the mass (>50 per cent), residing in small, dense clumps. Such a model might resemble the dense ISM in high-redshift galaxies. Peak driving results in huge radiative losses, producing a filamentary ISM with virtually no hot gas, and a small molecular hydrogen mass fraction (≪1 per cent). Varying the ratio of peak to random SNe yields ISM properties in between the two extremes, with a sharp transition for equal contributions. The velocity dispersion in H i remains ≲10 km s−1 in all cases. For peak driving, the velocity dispersion in Hα can be as high as 70 km s−1 due to the contribution from young, embedded SN remnants.