Modeling the Chemical Enrichment History of the Bulge Fossil Fragment Terzan 5
Terzan 5 is a heavily obscured stellar system located in the inner Galaxy. It has been postulated to be a stellar relic, a bulge fossil fragment witnessing the complex history of the assembly of the Milky Way bulge. In this paper, we follow the chemical enrichment of a set of putative progenitors of...
| Main Authors: | , , , , , , , , , , , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2023-01-01
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| Series: | The Astrophysical Journal |
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| Online Access: | https://doi.org/10.3847/1538-4357/acd8ba |
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| author | Donatella Romano Francesco R. Ferraro Livia Origlia Simon Portegies Zwart Barbara Lanzoni Chiara Crociati Davide Massari Emanuele Dalessandro Alessio Mucciarelli R. Michael Rich Francesco Calura Francesca Matteucci |
| author_facet | Donatella Romano Francesco R. Ferraro Livia Origlia Simon Portegies Zwart Barbara Lanzoni Chiara Crociati Davide Massari Emanuele Dalessandro Alessio Mucciarelli R. Michael Rich Francesco Calura Francesca Matteucci |
| author_sort | Donatella Romano |
| collection | DOAJ |
| description | Terzan 5 is a heavily obscured stellar system located in the inner Galaxy. It has been postulated to be a stellar relic, a bulge fossil fragment witnessing the complex history of the assembly of the Milky Way bulge. In this paper, we follow the chemical enrichment of a set of putative progenitors of Terzan 5 to assess whether the chemical properties of this cluster fit within a formation scenario in which it is the remnant of a primordial building block of the bulge. We can explain the metallicity distribution function and the runs of different element-to-iron abundance ratios as functions of [Fe/H] derived from optical-infrared spectroscopy of giant stars in Terzan 5 by assuming that the cluster experienced two major star formation bursts separated by a long quiescent phase. We further predict that the most metal-rich stars in Terzan 5 are moderately He-enhanced, and we predict a large spread of He abundances in the cluster, Y ≃ 0.26–0.335. We conclude that current observations fit within a formation scenario in which Terzan 5 originated from a pristine or slightly metal-enriched gas clump about one order of magnitude more massive than its present-day mass. Losses of gas and stars played a major role in shaping Terzan 5 the way we see it now. The iron content of the youngest stellar population is better explained if the white dwarfs that give rise to type Ia supernovae (the main Fe factories) sink toward the cluster center, rather than being stripped by the strong tidal forces exerted by the Milky Way in the outer regions. |
| first_indexed | 2024-03-12T04:08:28Z |
| format | Article |
| id | doaj.art-f6603fb06c0542faa570cbbb0b0a4e3a |
| institution | Directory Open Access Journal |
| issn | 1538-4357 |
| language | English |
| last_indexed | 2024-03-12T04:08:28Z |
| publishDate | 2023-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | The Astrophysical Journal |
| spelling | doaj.art-f6603fb06c0542faa570cbbb0b0a4e3a2023-09-03T11:11:14ZengIOP PublishingThe Astrophysical Journal1538-43572023-01-0195128510.3847/1538-4357/acd8baModeling the Chemical Enrichment History of the Bulge Fossil Fragment Terzan 5Donatella Romano0https://orcid.org/0000-0002-0845-6171Francesco R. Ferraro1https://orcid.org/0000-0002-2165-8528Livia Origlia2https://orcid.org/0000-0002-6040-5849Simon Portegies Zwart3https://orcid.org/0000-0001-5839-0302Barbara Lanzoni4https://orcid.org/0000-0001-5613-4938Chiara Crociati5https://orcid.org/0009-0002-8571-5170Davide Massari6https://orcid.org/0000-0001-8892-4301Emanuele Dalessandro7https://orcid.org/0000-0003-4237-4601Alessio Mucciarelli8https://orcid.org/0000-0001-9158-8580R. Michael Rich9https://orcid.org/0000-0003-0427-8387Francesco Calura10https://orcid.org/0000-0002-6175-0871Francesca Matteucci11https://orcid.org/0000-0001-7067-2302INAF , Osservatorio di Astrofisica e Scienza dello Spazio, Via Gobetti 93/3, I-40129 Bologna, Italy ; donatella.romano@inaf.itINAF , Osservatorio di Astrofisica e Scienza dello Spazio, Via Gobetti 93/3, I-40129 Bologna, Italy ; donatella.romano@inaf.it; Dipartimento di Fisica e Astronomia, Università di Bologna , Via Gobetti 93/2, I-40129 Bologna, ItalyINAF , Osservatorio di Astrofisica e Scienza dello Spazio, Via Gobetti 93/3, I-40129 Bologna, Italy ; donatella.romano@inaf.itLeiden Observatory, Leiden University , P.O. Box 9513, 2300 RA Leiden, The NetherlandsINAF , Osservatorio di Astrofisica e Scienza dello Spazio, Via Gobetti 93/3, I-40129 Bologna, Italy ; donatella.romano@inaf.it; Dipartimento di Fisica e Astronomia, Università di Bologna , Via Gobetti 93/2, I-40129 Bologna, ItalyINAF , Osservatorio di Astrofisica e Scienza dello Spazio, Via Gobetti 93/3, I-40129 Bologna, Italy ; donatella.romano@inaf.it; Dipartimento di Fisica e Astronomia, Università di Bologna , Via Gobetti 93/2, I-40129 Bologna, ItalyINAF , Osservatorio di Astrofisica e Scienza dello Spazio, Via Gobetti 93/3, I-40129 Bologna, Italy ; donatella.romano@inaf.itINAF , Osservatorio di Astrofisica e Scienza dello Spazio, Via Gobetti 93/3, I-40129 Bologna, Italy ; donatella.romano@inaf.itINAF , Osservatorio di Astrofisica e Scienza dello Spazio, Via Gobetti 93/3, I-40129 Bologna, Italy ; donatella.romano@inaf.it; Dipartimento di Fisica e Astronomia, Università di Bologna , Via Gobetti 93/2, I-40129 Bologna, ItalyDepartment of Physics and Astronomy, University of California , 90095 Los Angeles, CA, USAINAF , Osservatorio di Astrofisica e Scienza dello Spazio, Via Gobetti 93/3, I-40129 Bologna, Italy ; donatella.romano@inaf.itSezione di Astronomia, Dipartimento di Fisica, Università di Trieste , Via Tiepolo 11, I-34143 Trieste, Italy; INAF , Osservatorio Astronomico di Trieste, Via Tiepolo 11, I-34143 Trieste, Italy; INFN , Sezione di Trieste, Via Valerio 2, I-34127 Trieste, ItalyTerzan 5 is a heavily obscured stellar system located in the inner Galaxy. It has been postulated to be a stellar relic, a bulge fossil fragment witnessing the complex history of the assembly of the Milky Way bulge. In this paper, we follow the chemical enrichment of a set of putative progenitors of Terzan 5 to assess whether the chemical properties of this cluster fit within a formation scenario in which it is the remnant of a primordial building block of the bulge. We can explain the metallicity distribution function and the runs of different element-to-iron abundance ratios as functions of [Fe/H] derived from optical-infrared spectroscopy of giant stars in Terzan 5 by assuming that the cluster experienced two major star formation bursts separated by a long quiescent phase. We further predict that the most metal-rich stars in Terzan 5 are moderately He-enhanced, and we predict a large spread of He abundances in the cluster, Y ≃ 0.26–0.335. We conclude that current observations fit within a formation scenario in which Terzan 5 originated from a pristine or slightly metal-enriched gas clump about one order of magnitude more massive than its present-day mass. Losses of gas and stars played a major role in shaping Terzan 5 the way we see it now. The iron content of the youngest stellar population is better explained if the white dwarfs that give rise to type Ia supernovae (the main Fe factories) sink toward the cluster center, rather than being stripped by the strong tidal forces exerted by the Milky Way in the outer regions.https://doi.org/10.3847/1538-4357/acd8baGalactic bulgeGalactic archaeologyGalaxy chemical evolutionStar clustersStellar abundances |
| spellingShingle | Donatella Romano Francesco R. Ferraro Livia Origlia Simon Portegies Zwart Barbara Lanzoni Chiara Crociati Davide Massari Emanuele Dalessandro Alessio Mucciarelli R. Michael Rich Francesco Calura Francesca Matteucci Modeling the Chemical Enrichment History of the Bulge Fossil Fragment Terzan 5 The Astrophysical Journal Galactic bulge Galactic archaeology Galaxy chemical evolution Star clusters Stellar abundances |
| title | Modeling the Chemical Enrichment History of the Bulge Fossil Fragment Terzan 5 |
| title_full | Modeling the Chemical Enrichment History of the Bulge Fossil Fragment Terzan 5 |
| title_fullStr | Modeling the Chemical Enrichment History of the Bulge Fossil Fragment Terzan 5 |
| title_full_unstemmed | Modeling the Chemical Enrichment History of the Bulge Fossil Fragment Terzan 5 |
| title_short | Modeling the Chemical Enrichment History of the Bulge Fossil Fragment Terzan 5 |
| title_sort | modeling the chemical enrichment history of the bulge fossil fragment terzan 5 |
| topic | Galactic bulge Galactic archaeology Galaxy chemical evolution Star clusters Stellar abundances |
| url | https://doi.org/10.3847/1538-4357/acd8ba |
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