Cracking the relation between mass and 1P-star fraction of globular clusters: II. The masses in 1P and 2P stars as a second tool
Galactic globular clusters contain two main groups of stars, the pristine or 1P stars, and the polluted or 2P stars. The pristine-star fraction in clusters, F 1P , is a decreasing function of the cluster present-day mass, m prst. Paper I has introduced a model mapping the region of the (m prst, F 1P...
Gespeichert in:
| 1. Verfasser: | |
|---|---|
| Dokumenttyp: | Article (Journal) |
| Sprache: | Englisch |
| Veröffentlicht: |
2024 November 22
|
| In: |
The astrophysical journal
Year: 2024, Jahrgang: 976, Heft: 2, Pages: 1-12 |
| ISSN: | 1538-4357 |
| DOI: | 10.3847/1538-4357/ad85d7 |
| Online-Zugang: | Verlag, kostenfrei, Volltext: https://doi.org/10.3847/1538-4357/ad85d7 Verlag, kostenfrei, Volltext: https://dx.doi.org/10.3847/1538-4357/ad85d7 
|
| Verfasserangaben: | Geneviève Parmentier |
| Zusammenfassung: | Galactic globular clusters contain two main groups of stars, the pristine or 1P stars, and the polluted or 2P stars. The pristine-star fraction in clusters, F 1P , is a decreasing function of the cluster present-day mass, m prst. Paper I has introduced a model mapping the region of the (m prst, F 1P ) space occupied by clusters, with the cluster mass threshold for 2P-star formation a key building block. We now expand this model to the pristine-star fraction in dependence of the pristine- and polluted-population masses. A. P. Milone et al. found that F 1P anticorrelates more tightly with the polluted-population present-day mass, m 2P,prst, than with the cluster total mass, m prst. By contrast, F 1P anticorrelates poorly with the pristine-population current mass, m 1P,prst. We show the loose anticorrelation between F 1P and m 1P,prst to result from a roughly constant pristine-population mass in clusters as they start their long-term evolution in the Galactic tidal field. As for the tight anticorrelation between m 2P,prst and F 1P , it stems from the initially shallow relation between m 2P and F 1P . Clusters of the Large and Small Magellanic Clouds (LMC and SMC, respectively) appear to behave unexpectedly with respect to each other. For a given F 1P , LMC clusters are more massive than SMC clusters despite their enduring a stronger tidal field. This is opposite to how the Galactic outer- and inner-halo clusters behave. The explanation may lie in cluster formation conditions. Finally, we wonder whether the single-population clusters NGC 419 and Rup 106 formed as multiple-population clusters. |
|---|---|
| Beschreibung: | Gesehen am 02.06.2025 |
| Beschreibung: | Online Resource |
| ISSN: | 1538-4357 |
| DOI: | 10.3847/1538-4357/ad85d7 |