The joint evolution of baryons and dark matter haloes

We have studied the dark matter (DM) distribution in an ≈1012 h-1 M⊙ mass halo extracted from a simulation consistent with the concordance cosmology, where the physics regulating the transformation of gas into stars was allowed to change producing galaxies with different morphologies. The presence o...

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Autores principales: Pedrosa, S., Tissera, P.B., Scannapieco, C.
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Acceso en línea:http://hdl.handle.net/20.500.12110/paper_00358711_v402_n2_p776_Pedrosa
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spelling todo:paper_00358711_v402_n2_p776_Pedrosa2023-10-03T14:46:57Z The joint evolution of baryons and dark matter haloes Pedrosa, S. Tissera, P.B. Scannapieco, C. Dark matter Galaxies: haloes Galaxies: structure We have studied the dark matter (DM) distribution in an ≈1012 h-1 M⊙ mass halo extracted from a simulation consistent with the concordance cosmology, where the physics regulating the transformation of gas into stars was allowed to change producing galaxies with different morphologies. The presence of baryons produces the concentration of the DM halo with respect to its corresponding dissipationless run, but we found that this response does not only depend on the number of baryons gathered in the central region, but also depend on the way they have been assembled. DM and baryons affect each other in a complex way, so the formation history of a galaxy plays an important role in its final total mass distribution. Supernova (SN) feedback regulates the star formation and triggers galactic outflows not only in the central galaxy but also in its satellites. Our results suggest that, as the effects of SN feedback get stronger, satellites get less massive and can even be more easily disrupted by dynamical friction, transferring less angular momentum. We found indications that this angular momentum could be acquired not only by the outer part of the DM halo, but also by the inner ones and by the stellar component in the central galaxy. The latter effect produces stellar migration which contributes to changing the inner potential well, probably working against further DM contraction. As a consequence of the action of these processes, when the halo hosts a galaxy with an important disc structure formed by smooth gas accretion, it is more concentrated than when it hosts a spheroidal system which experienced more massive mergers and interactions. We also found that in the latter case, the halo has less radial velocity anisotropy than when the halo hosts a disc galaxy. In most of our runs with baryons, we do not detect the inversion of the velocity dispersion characteristic of the dissipationless haloes. We have found that rotation velocities for the systems that were able to develop a disc structure are in good agreement with the observations, and none of them has been formed satisfying the adiabatic contraction hypothesis. © 2009 The Authors. Journal compilation © 2009 RAS. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_00358711_v402_n2_p776_Pedrosa
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Dark matter
Galaxies: haloes
Galaxies: structure
spellingShingle Dark matter
Galaxies: haloes
Galaxies: structure
Pedrosa, S.
Tissera, P.B.
Scannapieco, C.
The joint evolution of baryons and dark matter haloes
topic_facet Dark matter
Galaxies: haloes
Galaxies: structure
description We have studied the dark matter (DM) distribution in an ≈1012 h-1 M⊙ mass halo extracted from a simulation consistent with the concordance cosmology, where the physics regulating the transformation of gas into stars was allowed to change producing galaxies with different morphologies. The presence of baryons produces the concentration of the DM halo with respect to its corresponding dissipationless run, but we found that this response does not only depend on the number of baryons gathered in the central region, but also depend on the way they have been assembled. DM and baryons affect each other in a complex way, so the formation history of a galaxy plays an important role in its final total mass distribution. Supernova (SN) feedback regulates the star formation and triggers galactic outflows not only in the central galaxy but also in its satellites. Our results suggest that, as the effects of SN feedback get stronger, satellites get less massive and can even be more easily disrupted by dynamical friction, transferring less angular momentum. We found indications that this angular momentum could be acquired not only by the outer part of the DM halo, but also by the inner ones and by the stellar component in the central galaxy. The latter effect produces stellar migration which contributes to changing the inner potential well, probably working against further DM contraction. As a consequence of the action of these processes, when the halo hosts a galaxy with an important disc structure formed by smooth gas accretion, it is more concentrated than when it hosts a spheroidal system which experienced more massive mergers and interactions. We also found that in the latter case, the halo has less radial velocity anisotropy than when the halo hosts a disc galaxy. In most of our runs with baryons, we do not detect the inversion of the velocity dispersion characteristic of the dissipationless haloes. We have found that rotation velocities for the systems that were able to develop a disc structure are in good agreement with the observations, and none of them has been formed satisfying the adiabatic contraction hypothesis. © 2009 The Authors. Journal compilation © 2009 RAS.
format JOUR
author Pedrosa, S.
Tissera, P.B.
Scannapieco, C.
author_facet Pedrosa, S.
Tissera, P.B.
Scannapieco, C.
author_sort Pedrosa, S.
title The joint evolution of baryons and dark matter haloes
title_short The joint evolution of baryons and dark matter haloes
title_full The joint evolution of baryons and dark matter haloes
title_fullStr The joint evolution of baryons and dark matter haloes
title_full_unstemmed The joint evolution of baryons and dark matter haloes
title_sort joint evolution of baryons and dark matter haloes
url http://hdl.handle.net/20.500.12110/paper_00358711_v402_n2_p776_Pedrosa
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