Chemical signatures of formation processes in the stellar populations of simulated galaxies

We study the chemical properties of the stellar populations in eight simulations of the formation of Milky Way mass galaxies in a Λ cold dark matter universe. Our simulations include metal-dependent cooling and an explicitly multiphase treatment of the effects on the gas of cooling, enrichment and s...

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Detalles Bibliográficos
Publicado: 2012
Materias:
Cosmology: theory
Galaxies: evolution
Galaxies: formation
Galaxy: abundances
Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00358711_v420_n1_p255_Tissera
http://hdl.handle.net/20.500.12110/paper_00358711_v420_n1_p255_Tissera
Aporte de:
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
id paper:paper_00358711_v420_n1_p255_Tissera
record_format dspace
spelling paper:paper_00358711_v420_n1_p255_Tissera2023-06-08T15:01:33Z Chemical signatures of formation processes in the stellar populations of simulated galaxies Cosmology: theory Galaxies: evolution Galaxies: formation Galaxy: abundances We study the chemical properties of the stellar populations in eight simulations of the formation of Milky Way mass galaxies in a Λ cold dark matter universe. Our simulations include metal-dependent cooling and an explicitly multiphase treatment of the effects on the gas of cooling, enrichment and supernova feedback. We search for correlations between formation history and chemical abundance patterns. Differing contributions to spheroids and discs from in situ star formation and from accreted populations are reflected in differing chemical properties. Discs have younger stellar populations, with most stars forming in situ and with low α-enhancement from gas which never participated in a galactic outflow. Up to 15per cent of disc stars can come from accreted satellites. These tend to be α-enhanced, older and to have larger velocity dispersions than the in situ population. Inner spheroids have old, metal-rich and α-enhanced stars which formed primarily in situ, more than 40per cent from material recycled through earlier galactic winds. Few accreted stars are found in the inner spheroid unless a major merger occurred recently. Such stars are older, more metal-poor and more α-enhanced than the in situ population. Stellar haloes tend to have low metallicity and high α-enhancement. The outer haloes are made primarily of accreted stars. Their mean metallicity and α-enhancement reflect the masses of the disrupted satellites where they formed: more massive satellites typically have higher [Fe/H] and lower [α/Fe]. Surviving satellites have distinctive chemical patterns which reflect their extended, bursty star formation histories. These produce lower α-enhancement at given metallicity than in the main galaxy, in agreement with observed trends in the Milky Way. © 2011 The Authors Monthly Notices of the Royal Astronomical Society © 2011 RAS. 2012 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00358711_v420_n1_p255_Tissera http://hdl.handle.net/20.500.12110/paper_00358711_v420_n1_p255_Tissera
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: evolution
Galaxies: formation
Galaxy: abundances
spellingShingle Cosmology: theory
Galaxies: evolution
Galaxies: formation
Galaxy: abundances
Chemical signatures of formation processes in the stellar populations of simulated galaxies
topic_facet Cosmology: theory
Galaxies: evolution
Galaxies: formation
Galaxy: abundances
description We study the chemical properties of the stellar populations in eight simulations of the formation of Milky Way mass galaxies in a Λ cold dark matter universe. Our simulations include metal-dependent cooling and an explicitly multiphase treatment of the effects on the gas of cooling, enrichment and supernova feedback. We search for correlations between formation history and chemical abundance patterns. Differing contributions to spheroids and discs from in situ star formation and from accreted populations are reflected in differing chemical properties. Discs have younger stellar populations, with most stars forming in situ and with low α-enhancement from gas which never participated in a galactic outflow. Up to 15per cent of disc stars can come from accreted satellites. These tend to be α-enhanced, older and to have larger velocity dispersions than the in situ population. Inner spheroids have old, metal-rich and α-enhanced stars which formed primarily in situ, more than 40per cent from material recycled through earlier galactic winds. Few accreted stars are found in the inner spheroid unless a major merger occurred recently. Such stars are older, more metal-poor and more α-enhanced than the in situ population. Stellar haloes tend to have low metallicity and high α-enhancement. The outer haloes are made primarily of accreted stars. Their mean metallicity and α-enhancement reflect the masses of the disrupted satellites where they formed: more massive satellites typically have higher [Fe/H] and lower [α/Fe]. Surviving satellites have distinctive chemical patterns which reflect their extended, bursty star formation histories. These produce lower α-enhancement at given metallicity than in the main galaxy, in agreement with observed trends in the Milky Way. © 2011 The Authors Monthly Notices of the Royal Astronomical Society © 2011 RAS.
title Chemical signatures of formation processes in the stellar populations of simulated galaxies
title_short Chemical signatures of formation processes in the stellar populations of simulated galaxies
title_full Chemical signatures of formation processes in the stellar populations of simulated galaxies
title_fullStr Chemical signatures of formation processes in the stellar populations of simulated galaxies
title_full_unstemmed Chemical signatures of formation processes in the stellar populations of simulated galaxies
title_sort chemical signatures of formation processes in the stellar populations of simulated galaxies
publishDate 2012
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00358711_v420_n1_p255_Tissera
http://hdl.handle.net/20.500.12110/paper_00358711_v420_n1_p255_Tissera
_version_ 1768542636730220544

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