Multiple Populations in Low-mass Globular Clusters: Palomar 13 - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue The Astrophysical Journal Année : 2021

Multiple Populations in Low-mass Globular Clusters: Palomar 13

Résumé

Abstract Since the discovery of chemically peculiar stars in globular clusters in the last century, the study of multiple populations has become increasingly important, given that chemical inhomogeneity is found in almost all globular clusters. Despite various proposed theories attempting to explain this phenomenon, fitting all the observational evidence in globular clusters with one single theory remains notoriously difficult and currently unsuccessful. In order to improve existing models and motivate new ones, we are observing globular clusters at critical conditions, e.g., metal-rich end, metal-poor end, and low mass end. In this paper, we present our first attempt to investigate multiple populations in low mass globular clusters. We obtained low-resolution spectra around 4000 Å of 30 members of the globular cluster Palomar 13 using OSIRIS/Multi-object spectrograph mounted at the Gran Telescopio Canarias. The membership of red giant branch stars is confirmed by the latest proper motions from Gaia DR2 and literature velocities. After comparing the measured CN and CH spectral indices with those of the stellar models, we found a clear sign of nitrogen variation among the red giant branch stars. Palomar 13 may be the lowest mass globular cluster showing multiple populations.

Dates et versions

hal-03592441 , version 1 (01-03-2022)

Identifiants

Citer

Baitian Tang, Yue Wang, Ruoyun Huang, Chengyuan Li, Jincheng Yu, et al.. Multiple Populations in Low-mass Globular Clusters: Palomar 13. The Astrophysical Journal, 2021, 908 (2), pp.220. ⟨10.3847/1538-4357/abd557⟩. ⟨hal-03592441⟩
12 Consultations
0 Téléchargements

Altmetric

Partager

Gmail Mastodon Facebook X LinkedIn More