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 h_3 (~skewness) and h_4 (~kurtosis) in galaxies to their cosmological assembly history. Here, we assess these results by measuring the stellar kinematics on a...
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ftcaltechauth:oai:authors.library.caltech.edu:73771 2023-05-15T18:11:25+02:00 The SAMI Galaxy Survey: Revisiting Galaxy Classification through High-order Stellar Kinematics van de Sande, Jesse Medling, Anne M. 2017-01-20 application/pdf https://authors.library.caltech.edu/73771/ https://authors.library.caltech.edu/73771/1/Sande_2017_ApJ_835_104.pdf https://authors.library.caltech.edu/73771/2/1611.07039v1.pdf https://resolver.caltech.edu/CaltechAUTHORS:20170127-091339895 en eng American Astronomical Society https://authors.library.caltech.edu/73771/1/Sande_2017_ApJ_835_104.pdf https://authors.library.caltech.edu/73771/2/1611.07039v1.pdf van de Sande, Jesse and Medling, Anne M. (2017) The SAMI Galaxy Survey: Revisiting Galaxy Classification through High-order Stellar Kinematics. Astrophysical Journal, 835 (1). Art. No. 104. ISSN 0004-637X. doi:10.3847/1538-4357/835/1/104. https://resolver.caltech.edu/CaltechAUTHORS:20170127-091339895 <https://resolver.caltech.edu/CaltechAUTHORS:20170127-091339895> other Article PeerReviewed 2017 ftcaltechauth https://doi.org/10.3847/1538-4357/835/1/104 2021-11-18T18:40:32Z Recent cosmological hydrodynamical simulations suggest that integral field spectroscopy can connect the high-order stellar kinematic moments h_3 (~skewness) and h_4 (~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 (λ_(R_e)) and ellipticity (ε_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 h_3 versus V/σ anti-correlation, whereas quasi-regular and non-regular rotators show a more vertical relation in h_3 and V/σ. Motivated by recent cosmological simulations, we develop an alternative approach to kinematically classify galaxies from their individual h_3 versus V/σ 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 λ_(R_e) - ε_e values can show distinctly different h_3 - V/σ signatures. Class 5 objects are previously unidentified fast rotators that show a weak h_3 versus V/σ 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 h_3 versus V/σ as evidence for disks in most fast rotators, suggesting a dearth of gas-poor mergers among fast rotators. Article in Journal/Newspaper sami Caltech Authors (California Institute of Technology) The Astrophysical Journal 835 1 104 |
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Caltech Authors (California Institute of Technology) |
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English |
description |
Recent cosmological hydrodynamical simulations suggest that integral field spectroscopy can connect the high-order stellar kinematic moments h_3 (~skewness) and h_4 (~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 (λ_(R_e)) and ellipticity (ε_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 h_3 versus V/σ anti-correlation, whereas quasi-regular and non-regular rotators show a more vertical relation in h_3 and V/σ. Motivated by recent cosmological simulations, we develop an alternative approach to kinematically classify galaxies from their individual h_3 versus V/σ 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 λ_(R_e) - ε_e values can show distinctly different h_3 - V/σ signatures. Class 5 objects are previously unidentified fast rotators that show a weak h_3 versus V/σ 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 h_3 versus V/σ as evidence for disks in most fast rotators, suggesting a dearth of gas-poor mergers among fast rotators. |
format |
Article in Journal/Newspaper |
author |
van de Sande, Jesse Medling, Anne M. |
spellingShingle |
van de Sande, Jesse Medling, Anne M. The SAMI Galaxy Survey: Revisiting Galaxy Classification through High-order Stellar Kinematics |
author_facet |
van de Sande, Jesse Medling, Anne M. |
author_sort |
van de Sande, Jesse |
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 |
American Astronomical Society |
publishDate |
2017 |
url |
https://authors.library.caltech.edu/73771/ https://authors.library.caltech.edu/73771/1/Sande_2017_ApJ_835_104.pdf https://authors.library.caltech.edu/73771/2/1611.07039v1.pdf https://resolver.caltech.edu/CaltechAUTHORS:20170127-091339895 |
genre |
sami |
genre_facet |
sami |
op_relation |
https://authors.library.caltech.edu/73771/1/Sande_2017_ApJ_835_104.pdf https://authors.library.caltech.edu/73771/2/1611.07039v1.pdf van de Sande, Jesse and Medling, Anne M. (2017) The SAMI Galaxy Survey: Revisiting Galaxy Classification through High-order Stellar Kinematics. Astrophysical Journal, 835 (1). Art. No. 104. ISSN 0004-637X. doi:10.3847/1538-4357/835/1/104. https://resolver.caltech.edu/CaltechAUTHORS:20170127-091339895 <https://resolver.caltech.edu/CaltechAUTHORS:20170127-091339895> |
op_rights |
other |
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_ |
1766184082676383744 |