The formation history of our Galaxy's nuclear stellar disc constrained from HST observations of the Quintuplet field
| Autor: | R. Schödel, F. Nogueras-Lara, M. Hosek, T. Do, J. Lu, A. Martínez Arranz, A. Ghez, R. M. Rich, A. Gardini, E. Gallego-Cano, M. Cano González, A. T. Gallego-Calvente |
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| Přispěvatelé: | Ministerio de Ciencia e Innovación (España), European Commission |
| Rok vydání: | 2023 |
| Předmět: | |
| DOI: | 10.48550/arxiv.2304.01791 |
| Popis: | This is an Open Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Context. Until recently it was thought that the nuclear stellar disc at the centre of our Galaxy was formed via quasi-continuous star formation over billions of years. However, an analysis of GALACTICNUCLEUS survey data indicates that > 80% of the mass of the stellar disc formed at least 8 Gyr ago and about 5% roughly 1 Gyr ago. Aims. Our aim is to derive new constraints on the formation history of the nuclear stellar disc. Methods. We analysed a catalogue of HST/WFC3-IR observations of the Quintuplet cluster field. From this catalogue, we selected about 24 000 field stars that probably belong to the nuclear stellar disc. We used red clump giants to deredden the sample and fit the resulting F153M luminosity function with a linear combination of theoretical luminosity functions created from different stellar evolutionary models. Results. We find that ≳70% of the stellar population in the nuclear disc probably formed more than 10 Gyr ago, while ∼15% formed in an event (or series of events) ∼1 Gyr ago. Up to 10% of the stars appear to have formed in the past tens to hundreds of Myr. These results do not change significantly for reasonable variations in the assumed mean metallicity, sample selection, reddening correction, or stellar evolutionary models. Conclusions. We confirm previous work that changed the formation paradigm for stars in the Galactic Centre. The nuclear stellar disc is indeed a very old structure. There seems to have been little star formation activity between its formation and about 1 Gyr ago. © The Authors 2023. RS, AMA, AG, EGC, MCG, and ATGC acknowledge financial support from the State Agency for Research of the Spanish MCIU through the “Center of Excellence Severo Ochoa” award for the Instituto de Astrofísica de Andalucía (SEV-2017-0709) and financial support from national project PGC2018-095049-B-C21 (MCIU/AEI/FEDER, UE). M.H. is supported by the Brinson Prize Fellowship. FNL gratefully acknowledges the sponsorship provided by the European Southern Observatory through a research fellowship. With funding from the Spanish government through the "Severo Ochoa Centre of Excellence" accreditation (CEX2021-001131-S). |
| Databáze: | OpenAIRE |
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