The SAMI Galaxy Survey: Revisiting Galaxy Classification through High-order Stellar Kinematics
Article
Article Title | The SAMI Galaxy Survey: Revisiting Galaxy Classification through High-order Stellar Kinematics |
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ERA Journal ID | 1057 |
Article Category | Article |
Authors | van de Sande, Jesse, Bland-Hawthorn, J., 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., Richards, Samuel N., Schaefer, Adam L., Sharp, Rob, Sweet, Sarah M., Taranu, Dan, Tonini, Chiara, Walcher, C. Jakob and Yi, Sukyoung K. |
Journal Title | The Astrophysical Journal: an international review of astronomy and astronomical physics |
Journal Citation | 835 (1) |
Article Number | 104 |
Number of Pages | 35 |
Year | 2017 |
Publisher | IOP Publishing |
Place of Publication | United States |
ISSN | 0004-637X |
1538-4357 | |
Digital Object Identifier (DOI) | https://doi.org/10.3847/1538-4357/835/1/104 |
Web Address (URL) | https://iopscience.iop.org/article/10.3847/1538-4357/835/1/104 |
Abstract | Recent cosmological hydrodynamical simulations suggest that integral field spectroscopy can connect the highorder 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 (lRe ) and ellipticity (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 s anti-correlation, whereas quasi-regular and non-regular rotators show a more vertical relation in h3 and V s. Motivated by recent cosmological simulations, we develop an alternative approach to kinematically classify galaxies from their individual h3 versus V s 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 lRe –e values can show distinctly different h V 3– s signatures. Class 5 objects are previously unidentified fast rotators that show a weak h3 versus V s 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 s as evidence for disks in most fast rotators, suggesting a dearth of gas-poor mergers among fast rotators. |
Keywords | cosmology: observations; galaxies: structure; galaxies: stellar content; galaxies: kinematics and dynamics; galaxies: formation; galaxies: evolution |
Related Output | |
Is supplemented by | The SAMI Galaxy Survey revisiting Galaxy classification through high-order stellar kinematics. (2017) |
Contains Sensitive Content | Does not contain sensitive content |
ANZSRC Field of Research 2020 | 510102. Astronomical instrumentation |
Public Notes | Files associated with this item cannot be displayed due to copyright restrictions, but may be accessed online. Please see the link in the URL field. |
Byline Affiliations | University of Sydney |
ARC Centre of Excellence for All Sky Astrophysics in 3 Dimensions, Australia | |
University of Western Australia | |
Australian National University | |
Australian Astronomical Observatory, Australia | |
University of North Carolina, United States | |
University of Oxford, United Kingdom | |
Macquarie University | |
University of Hawaii, United States | |
Korea Astronomy and Space Science Institute, Korea | |
University of Newcastle | |
National Innovation Centre, Australia | |
Max Planck Institute for Astronomy, Germany | |
School of Mathematics, Physics and Computing | |
California Institute of Technology (Caltech), United States | |
Yonsei University, Korea | |
University of Melbourne | |
Leibniz Institute for Astrophysics Potsdam, Germany |
https://research.usq.edu.au/item/z75wy/the-sami-galaxy-survey-revisiting-galaxy-classification-through-high-order-stellar-kinematics
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