Feedback and metal enrichment in cosmological SPH simulations - II. A multiphase model with supernova energy feedback

We have developed a new scheme to treat a multiphase interstellar medium in smoothed particle hydrodynamics simulations of galaxy formation. This scheme can represent a cospatial mixture of cold and hot ISM components, and is formulated without scale-dependent parameters. It is thus particularly sui...

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Publicado: 2006
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Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00358711_v371_n3_p1125_Scannapieco
http://hdl.handle.net/20.500.12110/paper_00358711_v371_n3_p1125_Scannapieco
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spelling paper:paper_00358711_v371_n3_p1125_Scannapieco2023-06-08T15:01:21Z Feedback and metal enrichment in cosmological SPH simulations - II. A multiphase model with supernova energy feedback Cosmology: theory Galaxies: abundances Galaxies: evolution Galaxies: formation Methods: N-body simulations We have developed a new scheme to treat a multiphase interstellar medium in smoothed particle hydrodynamics simulations of galaxy formation. This scheme can represent a cospatial mixture of cold and hot ISM components, and is formulated without scale-dependent parameters. It is thus particularly suited to studies of cosmological structure formation where galaxies with a wide range of masses form simultaneously. We also present new algorithms for energy and heavy element injection by supernovae, and show that together these schemes can reproduce several important observed effects in galaxy evolution. Both in collapsing systems and in quiescent galaxies our codes can reproduce the Kennicutt relation between the surface densities of gas and of star formation. Strongly metal-enhanced winds are generated in both cases with ratios of mass-loss to star formation which are similar to those observed. This leads to a self-regulated cycle for star formation activity. The overall impact of feedback depends on galaxy mass. Star formation is suppressed at most by a factor of a few in massive galaxies, but in low-mass systems the effects can be much larger, giving star formation an episodic, bursty character. The larger the energy fraction assumed available in feedback, the more massive the outflows and the lower the final stellar masses. Winds from forming discs are collimated perpendicular to the disc plane, reach velocities up to ∼1000kms-1, and efficiently transport metals out of the galaxies. The asymptotically unbound baryon fraction drops from >95 per cent to ∼30 per cent from the least to the most massive of our idealized galaxies, but the fraction of all metals ejected with this component exceeds 60 per cent regardless of mass. Such winds could plausibly enrich the intergalactic medium to observed levels. © 2006 RAS. 2006 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00358711_v371_n3_p1125_Scannapieco http://hdl.handle.net/20.500.12110/paper_00358711_v371_n3_p1125_Scannapieco
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Cosmology: theory
Galaxies: abundances
Galaxies: evolution
Galaxies: formation
Methods: N-body simulations
spellingShingle Cosmology: theory
Galaxies: abundances
Galaxies: evolution
Galaxies: formation
Methods: N-body simulations
Feedback and metal enrichment in cosmological SPH simulations - II. A multiphase model with supernova energy feedback
topic_facet Cosmology: theory
Galaxies: abundances
Galaxies: evolution
Galaxies: formation
Methods: N-body simulations
description We have developed a new scheme to treat a multiphase interstellar medium in smoothed particle hydrodynamics simulations of galaxy formation. This scheme can represent a cospatial mixture of cold and hot ISM components, and is formulated without scale-dependent parameters. It is thus particularly suited to studies of cosmological structure formation where galaxies with a wide range of masses form simultaneously. We also present new algorithms for energy and heavy element injection by supernovae, and show that together these schemes can reproduce several important observed effects in galaxy evolution. Both in collapsing systems and in quiescent galaxies our codes can reproduce the Kennicutt relation between the surface densities of gas and of star formation. Strongly metal-enhanced winds are generated in both cases with ratios of mass-loss to star formation which are similar to those observed. This leads to a self-regulated cycle for star formation activity. The overall impact of feedback depends on galaxy mass. Star formation is suppressed at most by a factor of a few in massive galaxies, but in low-mass systems the effects can be much larger, giving star formation an episodic, bursty character. The larger the energy fraction assumed available in feedback, the more massive the outflows and the lower the final stellar masses. Winds from forming discs are collimated perpendicular to the disc plane, reach velocities up to ∼1000kms-1, and efficiently transport metals out of the galaxies. The asymptotically unbound baryon fraction drops from >95 per cent to ∼30 per cent from the least to the most massive of our idealized galaxies, but the fraction of all metals ejected with this component exceeds 60 per cent regardless of mass. Such winds could plausibly enrich the intergalactic medium to observed levels. © 2006 RAS.
title Feedback and metal enrichment in cosmological SPH simulations - II. A multiphase model with supernova energy feedback
title_short Feedback and metal enrichment in cosmological SPH simulations - II. A multiphase model with supernova energy feedback
title_full Feedback and metal enrichment in cosmological SPH simulations - II. A multiphase model with supernova energy feedback
title_fullStr Feedback and metal enrichment in cosmological SPH simulations - II. A multiphase model with supernova energy feedback
title_full_unstemmed Feedback and metal enrichment in cosmological SPH simulations - II. A multiphase model with supernova energy feedback
title_sort feedback and metal enrichment in cosmological sph simulations - ii. a multiphase model with supernova energy feedback
publishDate 2006
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00358711_v371_n3_p1125_Scannapieco
http://hdl.handle.net/20.500.12110/paper_00358711_v371_n3_p1125_Scannapieco
_version_ 1768546387675316224