Environmental Quenching in the SAMI Galaxy Survey and Hydrodynamical Simulations
In this thesis, we investigate the mechanisms that quench star formation in all environments and how fast the quenching processes happen, especially in dense regions like groups and clusters. We have utilized the full sample from the SAMI Galaxy Survey, the EAGLE/C-EAGLE hydrodynamical simulation re...
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The University of Sydney
2023
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ftunivsydney:oai:ses.library.usyd.edu.au:2123/31490 2023-08-15T12:42:56+02:00 Environmental Quenching in the SAMI Galaxy Survey and Hydrodynamical Simulations Wang, Di 2023 application/pdf https://hdl.handle.net/2123/31490 en eng The University of Sydney Faculty of Science https://hdl.handle.net/2123/31490 The author retains copyright of this thesis. It may only be used for the purposes of research and study. It must not be used for any other purposes and may not be transmitted or shared with others without prior permission. galaxy star formation galaxy evolution galaxy groups galaxy clusters numerical Thesis Doctor of Philosophy 2023 ftunivsydney 2023-07-24T22:24:58Z In this thesis, we investigate the mechanisms that quench star formation in all environments and how fast the quenching processes happen, especially in dense regions like groups and clusters. We have utilized the full sample from the SAMI Galaxy Survey, the EAGLE/C-EAGLE hydrodynamical simulation results from z=0 to z=2, as well as the environmental metric and broadband photometric data from the GAMA catalogue. Firstly, we identify galaxies that are currently undergoing quenching processes with the spatially-resolved star formation distribution by using a star-formation concentration index (C-index). Denser environments have a higher fraction of galaxies with low C-index, indicating "outside-in" quenching due to ram pressure-stripping. However, at z > 1, quenching in simulations shows no clear "outside-in" signatures, limiting the C-index's use as a quenching proxy. Secondly, we investigate the physical properties influencing "outside-in" quenching in groups and clusters. Using the SAMI observational data, we find the formation of SF-concentrated galaxies is primarily influenced by the overall cluster environment rather than nearby galaxy interactions or local environments. Additionally, using infall timescale and orbital information from the Eagle simulations, we find that environmental quenching is more related to the closest approach radius and the duration of a galaxy's satellite phase, rather than its current position in groups or clusters. Lastly, we estimate quenching timescales for SF-concentrated galaxies. By analyzing the SAMI radial age profiles, high-mass group SF-concentrated galaxies have older ages in their outer discs (1-2 R_e) compared to ungrouped regular galaxies, with an age difference of ~2 Gyr. SED fitting with Bagpipes and SAMI data reveals faster quenching timescales in higher mass groups. Eagle simulations demonstrate slower quenching timescales (> 2 Gyr) at z=0 and more rapid quenching (< 2 Gyr) at higher redshifts (z > 1). Doctoral or Postdoctoral Thesis sami The University of Sydney: Sydney eScholarship Repository |
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The University of Sydney: Sydney eScholarship Repository |
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ftunivsydney |
language |
English |
topic |
galaxy star formation galaxy evolution galaxy groups galaxy clusters numerical |
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galaxy star formation galaxy evolution galaxy groups galaxy clusters numerical Wang, Di Environmental Quenching in the SAMI Galaxy Survey and Hydrodynamical Simulations |
topic_facet |
galaxy star formation galaxy evolution galaxy groups galaxy clusters numerical |
description |
In this thesis, we investigate the mechanisms that quench star formation in all environments and how fast the quenching processes happen, especially in dense regions like groups and clusters. We have utilized the full sample from the SAMI Galaxy Survey, the EAGLE/C-EAGLE hydrodynamical simulation results from z=0 to z=2, as well as the environmental metric and broadband photometric data from the GAMA catalogue. Firstly, we identify galaxies that are currently undergoing quenching processes with the spatially-resolved star formation distribution by using a star-formation concentration index (C-index). Denser environments have a higher fraction of galaxies with low C-index, indicating "outside-in" quenching due to ram pressure-stripping. However, at z > 1, quenching in simulations shows no clear "outside-in" signatures, limiting the C-index's use as a quenching proxy. Secondly, we investigate the physical properties influencing "outside-in" quenching in groups and clusters. Using the SAMI observational data, we find the formation of SF-concentrated galaxies is primarily influenced by the overall cluster environment rather than nearby galaxy interactions or local environments. Additionally, using infall timescale and orbital information from the Eagle simulations, we find that environmental quenching is more related to the closest approach radius and the duration of a galaxy's satellite phase, rather than its current position in groups or clusters. Lastly, we estimate quenching timescales for SF-concentrated galaxies. By analyzing the SAMI radial age profiles, high-mass group SF-concentrated galaxies have older ages in their outer discs (1-2 R_e) compared to ungrouped regular galaxies, with an age difference of ~2 Gyr. SED fitting with Bagpipes and SAMI data reveals faster quenching timescales in higher mass groups. Eagle simulations demonstrate slower quenching timescales (> 2 Gyr) at z=0 and more rapid quenching (< 2 Gyr) at higher redshifts (z > 1). |
format |
Doctoral or Postdoctoral Thesis |
author |
Wang, Di |
author_facet |
Wang, Di |
author_sort |
Wang, Di |
title |
Environmental Quenching in the SAMI Galaxy Survey and Hydrodynamical Simulations |
title_short |
Environmental Quenching in the SAMI Galaxy Survey and Hydrodynamical Simulations |
title_full |
Environmental Quenching in the SAMI Galaxy Survey and Hydrodynamical Simulations |
title_fullStr |
Environmental Quenching in the SAMI Galaxy Survey and Hydrodynamical Simulations |
title_full_unstemmed |
Environmental Quenching in the SAMI Galaxy Survey and Hydrodynamical Simulations |
title_sort |
environmental quenching in the sami galaxy survey and hydrodynamical simulations |
publisher |
The University of Sydney |
publishDate |
2023 |
url |
https://hdl.handle.net/2123/31490 |
genre |
sami |
genre_facet |
sami |
op_relation |
https://hdl.handle.net/2123/31490 |
op_rights |
The author retains copyright of this thesis. It may only be used for the purposes of research and study. It must not be used for any other purposes and may not be transmitted or shared with others without prior permission. |
_version_ |
1774297793592033280 |