Modelling the supernova-driven ISM in different environments
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...
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| Main Authors: | , , , , |
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| Format: | Article (Journal) |
| Language: | English |
| Published: |
20 March 2015
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| In: |
Monthly notices of the Royal Astronomical Society
Year: 2015, Volume: 449, Issue: 1, Pages: 1057-1075 |
| ISSN: | 1365-2966 |
| DOI: | 10.1093/mnras/stv324 |
| Online Access: | Verlag, lizenzpflichtig, Volltext: https://doi.org/10.1093/mnras/stv324
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| Author Notes: | 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 |
| Summary: | 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. |
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| Item Description: | Gesehen am 09.08.2021 |
| Physical Description: | Online Resource |
| ISSN: | 1365-2966 |
| DOI: | 10.1093/mnras/stv324 |