The GECKOS Survey: Identifying kinematic sub-structures in edge-on galaxies
- Autor(en)
- A. Fraser-McKelvie, J. van de Sande, D. A. Gadotti, E. Emsellem, T. Brown, D. B. Fisher, M. Martig, M. Bureau, O. Gerhard, A. J. Battisti, J. Bland-Hawthorn, B. Catinella, F. Combes, L. Cortese, S. M. Croom, T. A. Davis, J. Falcón-Barroso, F. Fragkoudi, K. C. Freeman, M. R. Hayden, R. McDermid, B. Mazzilli Ciraulo, J. T. Mendel, F. Pinna, A. Poci, T. H. Rutherford, C. de Sá-Freitas, L. A. Silva-Lima, L. M. Valenzuela, G. van de Ven, Z. Wang, A. B. Watts
- Abstrakt
The vertical evolution of galactic discs is governed by the sub-structures within them. We examine the diversity of kinematic sub-structure present in the first 12 galaxies observed from the GECKOS survey, a VLT/MUSE large programme providing a systematic study of 35 edge-on, Milky Way-mass disc galaxies. Employing the nGIST analysis pipeline, we derive the mean line-of-sight stellar velocity ($V_{\star}$), velocity dispersion ($\sigma_{\star}$), skew ($h_{3}$), and kurtosis ($h_{4}$) for the sample, and examine 2D maps and 1D line profiles. Visually, the majority of this sample (8/12) are found to possess boxy-peanut bulges and host the corresponding kinematic structure predicted for stellar bars viewed in projection. Four galaxies exhibit strong evidence for the presence of nuclear discs, including central $h_{3}$-$V_{\star}$ anti-correlations, `croissant'-shaped central depressions in $\sigma_{\star}$ maps, strong gradients in $h_{3}$, and positive $h_{4}$ plateaus over the expected nuclear disc extent. The strength of the $h_{3}$ feature corresponds to the size of the nuclear disc, measured from the $h_{3}$ turnover radius. We can explain the features within the kinematic maps of all sample galaxies via disc structure(s) alone. We do not find any need to invoke the existence of dispersion-dominated bulges. Obtaining the specialised data products for this paper and the broader GECKOS survey required significant development of existing integral field spectroscopic (IFS) analysis tools. Therefore, we also present the nGIST pipeline: a modern, sophisticated, and easy-to-use pipeline for the analysis of galaxy IFS data. We conclude that the variety of kinematic sub-structures seen in GECKOS galaxies requires a contemporary view of galaxy morphology, expanding on the traditional view of galaxy structure, and uniting the kinematic complexity observed in the Milky Way with the extragalactic.
- Organisation(en)
- Institut für Astrophysik
- Externe Organisation(en)
- European Southern Observatory (Germany), University of New South Wales, Durham University, National Research Council Canada (NRC-CNRC), Swinburne University of Technology, Liverpool John Moores University (LJMU), University of Oxford, Max-Planck-Institut für extraterrestrische Physik, University of Western Australia, Observatoire de Paris, The University of Sydney, Cardiff University, Instituto de Astrofísica de Canarias (IAC), Australian National University, University of Oklahoma, Macquarie University, Herzberg Astronomy and Astrophysics Research Centre, European Southern Observatory (Chile), Universidade de São Paulo, Ludwig-Maximilians-Universität München, University of Utah
- Journal
- Astronomy & Astrophysics
- Anzahl der Seiten
- 32
- ISSN
- 0004-6361
- Publikationsdatum
- 11-2024
- Peer-reviewed
- Ja
- ÖFOS 2012
- 103003 Astronomie, 103004 Astrophysik
- Schlagwörter
- Link zum Portal
- https://ucrisportal.univie.ac.at/de/publications/9b33cab6-5cae-4b43-a46e-51761fecd343