The nuclear stellar disc of the Milky Way as a tracer of the Galactic bar
Creators: name: Nogueras-Lara, Francisco
Publisher: name: Zenodo
Year: 2023
Subjects: Galactic centre; Galactic bulge

description: The nuclear stellar disc is a flat dense stellar structure at the heart of the Milky Way. Recent work shows that analogous structures are common in the nuclei of external spiral galaxies, where there is evidence of an age gradient indicating that they form inside-out from gas funnelled to the centre by the galactic bar. Analysing the stellar population of the nuclear disc at different radii, we find an age gradient along the line of sight. We detect the presence of a significant mass (~40% of the total stellar mass) of intermediate-age stars (2-7 Gyr) in the outer regions of the nuclear stellar disc that is not present in its innermost regions, in which ~90% of the stellar mass is older than 7 Gyr. Our results are consistent with an inside-out formation of the nuclear stellar disc, and suggest that the age distribution of the nuclear stellar disc is similar to the one found in external galaxies. This implies that bar-driven processes observed in external galaxies are also at play in the Milky Way. Hence, the nuclear stellar disc is related to the Galactic bar and its properties can give us insight into its age and formation history.
description: {"references": ["Nogueras-Lara, F., Gallego-Calvente, A. T., Dong, H., et al. (2018) \"GALACTICNUCLEUS: A high angular resolution JHK<sub>s</sub> imaging survey of the Galactic centre. I. Methodology, performance, and near-infrared extinction towards the Galactic centre,\" A&amp;A, 610, A83 - 2018A&amp;A...610A..83N", "Nogueras-Lara, F., Sch\u00f6del, R., Gallego-Calvente, A. T., et al. (2019) \"GALACTICNUCLEUS: A high-angular-resolution JHK<sub>s</sub> imaging survey of the Galactic centre. II. First data release of the catalogue and the most detailed CMDs of the GC,\" A&amp;A, 631, A20 - 2019A&amp;A...631A..20N", "Gadotti, D. A., S\u00e1nchez-Bl\u00e1zquez, P., Falc\u00f3n-Barroso, J., et al. (2019) \"Time Inference with MUSE in Extragalactic Rings (TIMER): properties of the survey and high-level data products,\" MNRAS, 482, 506-529 - 2019MNRAS.482..506G", "Bittner, A., S\u00e1nchez-Bl\u00e1zquez, P., Gadotti, D. A., et al. (2020) \"Inside-out formation of nuclear discs and the absence of old central spheroids in barred galaxies of the TIMER survey,\" A&amp;A, 643, A65 - 2020A&amp;A...643A..65B", "Nogueras-Lara, F., Sch\u00f6del, R., Gallego-Calvente, A. T., et al. (2020) \"Early formation and recent starburst activity in the nuclear disk of the Milky Way,\" NatAs, 4, 377-381 - 2020NatAs...4..377N", "Fritz, T. K., Patrick, L. R., Feldmeier-Krause, A., et al. (2021) \"A KMOS survey of the nuclear disk of the Milky Way. I. Survey design and metallicities,\" A&amp;A, 649, A83 - 2021A&amp;A...649A..83F", "Nogueras-Lara, F., Sch\u00f6del, R., &amp; Neumayer, N. (2022) \"Detection of an excess of young stars in the Galactic Centre Sagittarius B1 region,\" NatAs, 6, 1178-1184 - 2022NatAs...6.1178N", "Nogueras-Lara, F. (2022) \"A first glimpse at the line-of-sight structure of the Milky Way's nuclear stellar disc,\" A&amp;A, 668, L8 - 2022A&amp;A...668L...8N", "Feldmeier-Krause, A. (2022) \"Stellar populations in the transition region of nuclear star cluster and nuclear stellar disc,\" MNRAS, 513, 5920-5934 - 2022MNRAS.513.5920F", "Nogueras-Lara, F., Schultheis, M., Najarro, F., et al. (2023) \"Evidence of an age gradient along the line of sight in the nuclear stellar disc of the Milky Way,\" A&amp;A, 671, L10 - 2023A&amp;A...671L..10N"]}