Formation history, structure and dynamics of discs and spheroids in simulated Milky Way mass galaxies

We study the stellar discs and spheroids in eight simulations of galaxy formation within Milky Way mass haloes in a Λ cold dark matter cosmology. The first paper in this series concentrated on disc properties. Here we extend this analysis to study how the formation history, structure and dynamics of...

Descripción completa

Guardado en:

Detalles Bibliográficos
Autores principales:	Scannapieco, C., White, S.D.M., Springel, V., Tissera, P.B.
Formato:	JOUR
Materias:	Cosmology: theory Galaxies: evolution Galaxies: formation Galaxies: structure Methods: numerical
Acceso en línea:	http://hdl.handle.net/20.500.12110/paper_00358711_v417_n1_p154_Scannapieco
Aporte de:	Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires

id	todo:paper_00358711_v417_n1_p154_Scannapieco
record_format	dspace
spelling	todo:paper_00358711_v417_n1_p154_Scannapieco2023-10-03T14:47:00Z Formation history, structure and dynamics of discs and spheroids in simulated Milky Way mass galaxies Scannapieco, C. White, S.D.M. Springel, V. Tissera, P.B. Cosmology: theory Galaxies: evolution Galaxies: formation Galaxies: structure Methods: numerical We study the stellar discs and spheroids in eight simulations of galaxy formation within Milky Way mass haloes in a Λ cold dark matter cosmology. The first paper in this series concentrated on disc properties. Here we extend this analysis to study how the formation history, structure and dynamics of discs and spheroids relate to the assembly history and structure of their haloes. We find that discs are generally young, with stars spanning a wide range of stellar age: the youngest stars define thin discs and have near-circular orbits, while the oldest stars form thicker discs that rotate ∼2 times slower than the thin components, and have 2-3 times larger velocity dispersions. Unlike the discs, spheroids form early and on short time-scales, and are dominated by velocity dispersion. We find great variety in their structure. The inner regions are bar- or bulge-like, while the extended outer haloes are rich in complex non-equilibrium structures such as stellar streams, shells and clumps. Our discs have very high in situ fractions, i.e. most of their stars formed in the disc itself. Nevertheless, there is a non-negligible contribution (∼15 per cent) from satellites that are accreted on nearly coplanar orbits. The inner regions of spheroids also have relatively high in situ fractions, but 65-85 per cent of their outer stellar population is accreted. We analyse the circular velocities, rotation velocities and velocity dispersions of our discs and spheroids, both for gas and stars, showing that the dynamical structure is complex as a result of the non-trivial interplay between cooling and supernova heating. © 2011 The Authors Monthly Notices of the Royal Astronomical Society © 2011 RAS. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_00358711_v417_n1_p154_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: evolution Galaxies: formation Galaxies: structure Methods: numerical
spellingShingle	Cosmology: theory Galaxies: evolution Galaxies: formation Galaxies: structure Methods: numerical Scannapieco, C. White, S.D.M. Springel, V. Tissera, P.B. Formation history, structure and dynamics of discs and spheroids in simulated Milky Way mass galaxies
topic_facet	Cosmology: theory Galaxies: evolution Galaxies: formation Galaxies: structure Methods: numerical
description	We study the stellar discs and spheroids in eight simulations of galaxy formation within Milky Way mass haloes in a Λ cold dark matter cosmology. The first paper in this series concentrated on disc properties. Here we extend this analysis to study how the formation history, structure and dynamics of discs and spheroids relate to the assembly history and structure of their haloes. We find that discs are generally young, with stars spanning a wide range of stellar age: the youngest stars define thin discs and have near-circular orbits, while the oldest stars form thicker discs that rotate ∼2 times slower than the thin components, and have 2-3 times larger velocity dispersions. Unlike the discs, spheroids form early and on short time-scales, and are dominated by velocity dispersion. We find great variety in their structure. The inner regions are bar- or bulge-like, while the extended outer haloes are rich in complex non-equilibrium structures such as stellar streams, shells and clumps. Our discs have very high in situ fractions, i.e. most of their stars formed in the disc itself. Nevertheless, there is a non-negligible contribution (∼15 per cent) from satellites that are accreted on nearly coplanar orbits. The inner regions of spheroids also have relatively high in situ fractions, but 65-85 per cent of their outer stellar population is accreted. We analyse the circular velocities, rotation velocities and velocity dispersions of our discs and spheroids, both for gas and stars, showing that the dynamical structure is complex as a result of the non-trivial interplay between cooling and supernova heating. © 2011 The Authors Monthly Notices of the Royal Astronomical Society © 2011 RAS.
format	JOUR
author	Scannapieco, C. White, S.D.M. Springel, V. Tissera, P.B.
author_facet	Scannapieco, C. White, S.D.M. Springel, V. Tissera, P.B.
author_sort	Scannapieco, C.
title	Formation history, structure and dynamics of discs and spheroids in simulated Milky Way mass galaxies
title_short	Formation history, structure and dynamics of discs and spheroids in simulated Milky Way mass galaxies
title_full	Formation history, structure and dynamics of discs and spheroids in simulated Milky Way mass galaxies
title_fullStr	Formation history, structure and dynamics of discs and spheroids in simulated Milky Way mass galaxies
title_full_unstemmed	Formation history, structure and dynamics of discs and spheroids in simulated Milky Way mass galaxies
title_sort	formation history, structure and dynamics of discs and spheroids in simulated milky way mass galaxies
url	http://hdl.handle.net/20.500.12110/paper_00358711_v417_n1_p154_Scannapieco
work_keys_str_mv	AT scannapiecoc formationhistorystructureanddynamicsofdiscsandspheroidsinsimulatedmilkywaymassgalaxies AT whitesdm formationhistorystructureanddynamicsofdiscsandspheroidsinsimulatedmilkywaymassgalaxies AT springelv formationhistorystructureanddynamicsofdiscsandspheroidsinsimulatedmilkywaymassgalaxies AT tisserapb formationhistorystructureanddynamicsofdiscsandspheroidsinsimulatedmilkywaymassgalaxies
_version_	1807319015148748800

Formation history, structure and dynamics of discs and spheroids in simulated Milky Way mass galaxies

Ejemplares similares