The SAMI Galaxy Survey: revisiting galaxy classification through high-order stellar kinematics
Recent cosmological hydrodynamical simulations suggest that integral field spectroscopy can connect the high-order stellar kinematic moments h3 (~skewness) and h4 (~kurtosis) in galaxies to their cosmological assembly history. Here, we assess these results by measuring the stellar kinematics on a sa...
Published in: | The Astrophysical Journal |
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Institute of Physics Publishing
2017
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Online Access: | https://espace.library.uq.edu.au/view/UQ:9ead066/UQ9ead066_OA.pdf https://espace.library.uq.edu.au/view/UQ:9ead066 |
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ftunivqespace:oai:espace.library.uq.edu.au:UQ:9ead066 2023-05-15T18:11:30+02:00 The SAMI Galaxy Survey: revisiting galaxy classification through high-order stellar kinematics Sande, Jesse van de Bland-Hawthorn, Joss Fogarty, Lisa M. R. Cortese, Luca d’Eugenio, Francesco Croom, Scott M. Scott, Nicholas Allen, James T. Brough, Sarah Bryant, Julia J. Cecil, Gerald Colless, Matthew Couch, Warrick J. Davies, Roger Elahi, Pascal J. Foster, Caroline Goldstein, Gregory Goodwin, Michael Groves, Brent Ho, I-Ting Jeong, Hyunjin Jones, D. Heath Konstantopoulos, Iraklis S. Lawrence, Jon S. Leslie, Sarah K. López-Sánchez, Ángel R. McDermid, Richard M. McElroy, Rebecca Medling, Anne M. Oh, Sree Owers, Matt S. 2017-01-20 https://espace.library.uq.edu.au/view/UQ:9ead066/UQ9ead066_OA.pdf https://espace.library.uq.edu.au/view/UQ:9ead066 unknown Institute of Physics Publishing doi:10.3847/1538-4357/835/1/104 issn:1538-4357 issn:0004-637X Space and Planetary Science Astronomy and Astrophysics Journal Article 2017 ftunivqespace https://doi.org/10.3847/1538-4357/835/1/104 2020-10-27T06:13:35Z Recent cosmological hydrodynamical simulations suggest that integral field spectroscopy can connect the high-order stellar kinematic moments h3 (~skewness) and h4 (~kurtosis) in galaxies to their cosmological assembly history. Here, we assess these results by measuring the stellar kinematics on a sample of 315 galaxies, without a morphological selection, using two-dimensional integral field data from the SAMI Galaxy Survey. Proxies for the spin parameter (${\lambda }_{{R}_{{\rm{e}}}}$) and ellipticity (${\epsilon }_{{\rm{e}}}$) are used to separate fast and slow rotators; there exists a good correspondence to regular and non-regular rotators, respectively, as also seen in earlier studies. We confirm that regular rotators show a strong h3 versus $V/\sigma $ anti-correlation, whereas quasi-regular and non-regular rotators show a more vertical relation in h3 and $V/\sigma $. Motivated by recent cosmological simulations, we develop an alternative approach to kinematically classify galaxies from their individual h3 versus $V/\sigma $ signatures. Within the SAMI Galaxy Survey, we identify five classes of high-order stellar kinematic signatures using Gaussian mixture models. Class 1 corresponds to slow rotators, whereas Classes 2–5 correspond to fast rotators. We find that galaxies with similar ${\lambda }_{{R}_{{\rm{e}}}}\mbox{--}{\epsilon }_{{\rm{e}}}$ values can show distinctly different ${h}_{3}\mbox{--}V/\sigma $ signatures. Class 5 objects are previously unidentified fast rotators that show a weak h3 versus $V/\sigma $ anti-correlation. From simulations, these objects are predicted to be disk-less galaxies formed by gas-poor mergers. From morphological examination, however, there is evidence for large stellar disks. Instead, Class 5 objects are more likely disturbed galaxies, have counter-rotating bulges, or bars in edge-on galaxies. Finally, we interpret the strong anti-correlation in h3 versus $V/\sigma $ as evidence for disks in most fast rotators, suggesting a dearth of gas-poor mergers among fast rotators. Article in Journal/Newspaper sami The University of Queensland: UQ eSpace Lambda ENVELOPE(-62.983,-62.983,-64.300,-64.300) The Astrophysical Journal 835 1 104 |
institution |
Open Polar |
collection |
The University of Queensland: UQ eSpace |
op_collection_id |
ftunivqespace |
language |
unknown |
topic |
Space and Planetary Science Astronomy and Astrophysics |
spellingShingle |
Space and Planetary Science Astronomy and Astrophysics Sande, Jesse van de Bland-Hawthorn, Joss Fogarty, Lisa M. R. Cortese, Luca d’Eugenio, Francesco Croom, Scott M. Scott, Nicholas Allen, James T. Brough, Sarah Bryant, Julia J. Cecil, Gerald Colless, Matthew Couch, Warrick J. Davies, Roger Elahi, Pascal J. Foster, Caroline Goldstein, Gregory Goodwin, Michael Groves, Brent Ho, I-Ting Jeong, Hyunjin Jones, D. Heath Konstantopoulos, Iraklis S. Lawrence, Jon S. Leslie, Sarah K. López-Sánchez, Ángel R. McDermid, Richard M. McElroy, Rebecca Medling, Anne M. Oh, Sree Owers, Matt S. The SAMI Galaxy Survey: revisiting galaxy classification through high-order stellar kinematics |
topic_facet |
Space and Planetary Science Astronomy and Astrophysics |
description |
Recent cosmological hydrodynamical simulations suggest that integral field spectroscopy can connect the high-order stellar kinematic moments h3 (~skewness) and h4 (~kurtosis) in galaxies to their cosmological assembly history. Here, we assess these results by measuring the stellar kinematics on a sample of 315 galaxies, without a morphological selection, using two-dimensional integral field data from the SAMI Galaxy Survey. Proxies for the spin parameter (${\lambda }_{{R}_{{\rm{e}}}}$) and ellipticity (${\epsilon }_{{\rm{e}}}$) are used to separate fast and slow rotators; there exists a good correspondence to regular and non-regular rotators, respectively, as also seen in earlier studies. We confirm that regular rotators show a strong h3 versus $V/\sigma $ anti-correlation, whereas quasi-regular and non-regular rotators show a more vertical relation in h3 and $V/\sigma $. Motivated by recent cosmological simulations, we develop an alternative approach to kinematically classify galaxies from their individual h3 versus $V/\sigma $ signatures. Within the SAMI Galaxy Survey, we identify five classes of high-order stellar kinematic signatures using Gaussian mixture models. Class 1 corresponds to slow rotators, whereas Classes 2–5 correspond to fast rotators. We find that galaxies with similar ${\lambda }_{{R}_{{\rm{e}}}}\mbox{--}{\epsilon }_{{\rm{e}}}$ values can show distinctly different ${h}_{3}\mbox{--}V/\sigma $ signatures. Class 5 objects are previously unidentified fast rotators that show a weak h3 versus $V/\sigma $ anti-correlation. From simulations, these objects are predicted to be disk-less galaxies formed by gas-poor mergers. From morphological examination, however, there is evidence for large stellar disks. Instead, Class 5 objects are more likely disturbed galaxies, have counter-rotating bulges, or bars in edge-on galaxies. Finally, we interpret the strong anti-correlation in h3 versus $V/\sigma $ as evidence for disks in most fast rotators, suggesting a dearth of gas-poor mergers among fast rotators. |
format |
Article in Journal/Newspaper |
author |
Sande, Jesse van de Bland-Hawthorn, Joss Fogarty, Lisa M. R. Cortese, Luca d’Eugenio, Francesco Croom, Scott M. Scott, Nicholas Allen, James T. Brough, Sarah Bryant, Julia J. Cecil, Gerald Colless, Matthew Couch, Warrick J. Davies, Roger Elahi, Pascal J. Foster, Caroline Goldstein, Gregory Goodwin, Michael Groves, Brent Ho, I-Ting Jeong, Hyunjin Jones, D. Heath Konstantopoulos, Iraklis S. Lawrence, Jon S. Leslie, Sarah K. López-Sánchez, Ángel R. McDermid, Richard M. McElroy, Rebecca Medling, Anne M. Oh, Sree Owers, Matt S. |
author_facet |
Sande, Jesse van de Bland-Hawthorn, Joss Fogarty, Lisa M. R. Cortese, Luca d’Eugenio, Francesco Croom, Scott M. Scott, Nicholas Allen, James T. Brough, Sarah Bryant, Julia J. Cecil, Gerald Colless, Matthew Couch, Warrick J. Davies, Roger Elahi, Pascal J. Foster, Caroline Goldstein, Gregory Goodwin, Michael Groves, Brent Ho, I-Ting Jeong, Hyunjin Jones, D. Heath Konstantopoulos, Iraklis S. Lawrence, Jon S. Leslie, Sarah K. López-Sánchez, Ángel R. McDermid, Richard M. McElroy, Rebecca Medling, Anne M. Oh, Sree Owers, Matt S. |
author_sort |
Sande, Jesse van de |
title |
The SAMI Galaxy Survey: revisiting galaxy classification through high-order stellar kinematics |
title_short |
The SAMI Galaxy Survey: revisiting galaxy classification through high-order stellar kinematics |
title_full |
The SAMI Galaxy Survey: revisiting galaxy classification through high-order stellar kinematics |
title_fullStr |
The SAMI Galaxy Survey: revisiting galaxy classification through high-order stellar kinematics |
title_full_unstemmed |
The SAMI Galaxy Survey: revisiting galaxy classification through high-order stellar kinematics |
title_sort |
sami galaxy survey: revisiting galaxy classification through high-order stellar kinematics |
publisher |
Institute of Physics Publishing |
publishDate |
2017 |
url |
https://espace.library.uq.edu.au/view/UQ:9ead066/UQ9ead066_OA.pdf https://espace.library.uq.edu.au/view/UQ:9ead066 |
long_lat |
ENVELOPE(-62.983,-62.983,-64.300,-64.300) |
geographic |
Lambda |
geographic_facet |
Lambda |
genre |
sami |
genre_facet |
sami |
op_relation |
doi:10.3847/1538-4357/835/1/104 issn:1538-4357 issn:0004-637X |
op_doi |
https://doi.org/10.3847/1538-4357/835/1/104 |
container_title |
The Astrophysical Journal |
container_volume |
835 |
container_issue |
1 |
container_start_page |
104 |
_version_ |
1766184150100869120 |