Using 26Al to detect ongoing self-enrichment in young massive star clusters
Self-enrichment is one of the leading explanations for chemical anomalies in globular clusters. In this scenario, various candidate polluter stars have been proposed to eject gas with altered chemical composition during the self-enrichment process. Most of the proposed polluters will also eject radi...
| Autores: | , , , , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2024 |
| País: | España |
| Institución: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/371831 |
| Acceso en línea: | http://hdl.handle.net/10261/371831 |
| Access Level: | acceso abierto |
| Palabra clave: | ISM: nuclear reactions Nucleosynthesis Stars: abundances Globular clusters: general |
| Sumario: | Self-enrichment is one of the leading explanations for chemical anomalies in globular clusters. In this scenario, various candidate polluter stars have been proposed to eject gas with altered chemical composition during the self-enrichment process. Most of the proposed polluters will also eject radioactive 26 Al into the surroundings. Hence, any detection of 26 Al in young massive star clusters (YMCs) would support the self-enrichment scenario if YMCs were indeed the progenitors of globular clusters. Observations of gamma-ray data from COMPTEL and INTEGRAL, as well as detections of 26 AlF molecules by the Atacama Large Millimeter-submillimeter Array (ALMA), indicate the maturing of 26 Al detection methods. Detection possibilities will be enhanced in the short- to mid-term by the upcoming launch of the Compton Spectrometer and Imager (COSI). The Square Kilometre Array (SKA) could in principle also detect radio recombination lines of the positronium formed from the decay products of 26 Al. Here, we show for a sample of YMCs in the nearby Universe, where self-enrichment could plausibly take place. For some nearby galaxies, this could enhance 26 Al by an order of one magnitude. Detecting 26 AlF with ALMA appears feasible for many candidate self-enrichment clusters, although significant challenges remain with other detection methods. The Large Magellanic Cloud, with its YMC R136, stands out as the most promising candidate. Detecting a 1.8 MeV radioactive decay line of 26 Al here would require at least 15 months of targeted observation with COSI, assuming ongoing self-enrichment in R136. |
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