Disc galaxies are still settling
- Author(s)
- Camila de Sá-Freitas, Dimitri A. Gadotti, Francesca Fragkoudi, Lodovico Coccato, Paula Coelho, Adriana de Lorenzo-Cáceres, Jesús Falcón-Barroso, Tutku Kolcu, Ignacio Martín-Navarro, Jairo Mendez-Abreu, Justus Neumann, Patricia Sanchez Blazquez, Miguel Querejeta, Glenn van de Ven
- Abstract
When galactic discs settle and become massive enough, they are able to form stellar bars. These non-axisymmetric structures induce shocks in the gas, causing it to flow to the centre where nuclear structures, such as nuclear discs and rings, are formed. Previous theoretical and observational studies have hinted at the co-evolution of bars and nuclear discs, suggesting that nuclear discs grow 'inside-out' and thereby proposing that smaller discs reside in younger bars. Nevertheless, it remains unclear how the bar and the nuclear structures form and evolve over time. The smallest nuclear discs discovered to date tend to be larger than ∼200 pc, even though some theoretical studies have reported that when nuclear discs form, they can be much smaller. Using MUSE archival data, we report, for the first time, two extragalactic nuclear discs with radius measurements below 100 pc. Additionally, our estimations reveal the youngest bars found to date. We estimate that the bars in these galaxies formed 4.50
-1.10
+1.60(sys)
-0.75
+1.00(stat) and 0.7
+2.60(sys)
-0.05
+0.05(stat) Gyr ago, for NGC 289 and NGC 1566, respectively. This suggests that at least some disc galaxies in the Local Universe may still be dynamically settling. By adding these results to previous findings in the literature, we are able to retrieve a stronger correlation between nuclear disc size and bar length. We also derive a tentative exponential growth scenario for nuclear discs.
- Organisation(s)
- Department of Astrophysics
- External organisation(s)
- European Southern Observatory (Germany), Durham University, University of São Paulo, University of La Laguna, Liverpool John Moores University (LJMU), Max-Planck-Institut für Astronomie, Universidad Complutense de Madrid, Observatorio Astronómico Nacional (OAN-IGN)
- Journal
- Astronomy & Astrophysics
- Volume
- 678
- No. of pages
- 12
- ISSN
- 0004-6361
- DOI
- https://doi.org/10.1051/0004-6361/202347028
- Publication date
- 10-2023
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 103003 Astronomy, 103004 Astrophysics
- Keywords
- ASJC Scopus subject areas
- Astronomy and Astrophysics, Space and Planetary Science
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/41e2ff93-2e0d-4255-8be2-09757dd4fe21