Facial reconstruction

Search LJMU Research Online

Browse Repository | Browse E-Theses

Disc galaxies are still settling: Discovery of the smallest nuclear discs and their young stellar bars

De Sá-Freitas, C, Gadotti, DA, Fragkoudi, F, Coccato, L, Coelho, P, De Lorenzo-Cáceres, A, Falcón-Barroso, J, Kolcu, T, Martín-Navarro, I, Mendez-Abreu, J, Neumann, J, Blazquez, PS, Querejeta, M and Van De Ven, G (2023) Disc galaxies are still settling: Discovery of the smallest nuclear discs and their young stellar bars. Astronomy & Astrophysics, 678. pp. 1-12. ISSN 0004-6361

Disc galaxies are still settling & Astrophysics Discovery of the smallest nuclear discs and their young stellar bars.pdf - Published Version
Available under License Creative Commons Attribution.

Download (2MB) | Preview


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.

Item Type: Article
Uncontrolled Keywords: 0201 Astronomical and Space Sciences; Astronomy & Astrophysics
Subjects: Q Science > QB Astronomy
Q Science > QC Physics
Divisions: Astrophysics Research Institute
Publisher: EDP Sciences
SWORD Depositor: A Symplectic
Date Deposited: 13 May 2024 11:30
Last Modified: 13 May 2024 11:30
DOI or ID number: 10.1051/0004-6361/202347028
URI: https://researchonline.ljmu.ac.uk/id/eprint/23233
View Item View Item