The mass functions of multiple stellar populations in 47 Tucanae

Abstract

We used a combination of James Webb Space Telescope (JWST) and Hubble Space Telescope (HST) observations to investigate the mass functions (MFs) of the different stellar populations in the globular cluster (GC) 47 Tucanae (NGC 104) over a wide stellar-mass interval. We identified the multiple populations along the lower main sequence using only JWST photometry and, in particular, colour combinations sensitive to variations in oxygen abundance. We derived the MFs of the first- and second-population (1P and 2P) stars separately and found that in the low-mass regime, the present-day MF of the 1P population is significantly steeper than that of the 2P population, which appears nearly flat. We also present the results of a dynamical model showing that this behaviour requires a different initial mass function (IMF) for the 2P and the 1P populations in the 0.1-0.4 solar masses mass range, thus providing a new fundamental constraint for the study of the star formation of multiple populations in GCs.

arXiv comment6 pages, 6 figures (3 in Appendices A-B), 1 table in Appendix A. Published in A&A Letters (https://doi.org/10.1051/0004-6361/202661178). Accepted on 8 July 2026

References in corpus (26)

• On the variation of the Initial Mass Function
• The Gaia mission
• Gaia Data Release 3: Summary of the content and survey properties
• Formation and Dynamical Evolution of Multiple Stellar Generations in Globular Clusters
• The ACS Survey of Galactic Globular Clusters. I. Overview and Clusters Without Previous HST Photometry
• The ACS Survey of Galactic Globular Clusters. XII. Photometric Binaries along the Main-Sequence
• Model Atmospheres for M (Sub)Dwarfs: I. The base model grid
• Clouds and Chemistry: Ultracool Dwarf Atmospheric Properties from Optical and Infrared Colors
• What is a globular cluster? An observational perspective
• Multiple stellar populations in 47 Tucanae
• MOCCA code for star cluster simulations - I. Blue Stragglers, first results
• Reaching the End of the White Dwarf Cooling Sequence in NGC 6791
• The End of the White Dwarf Cooling Sequence in M4: an efficient approach
• Rotation and multiple stellar population in globular clusters
• Monte Carlo Simulations of Star Clusters - VII. The globular cluster 47 Tuc
• Photometry and astrometry with JWST -- I. NIRCam Point Spread Functions and the first JWST colour-magnitude diagrams of a globular cluster
• Evidence for a bottom-light initial mass function in massive star clusters
• The State-of-the-Art HST Astro-Photometric Analysis of the core of $\omega$ Centauri. II. Differential-Reddening Map
• Multiple Stellar Populations in Globular Clusters with JWST: a NIRCam view of 47 Tucanae
• Evolution of the Stellar Mass Function in Multiple-Population Globular Clusters
• Radial variation of the stellar mass functions in the globular clusters M15 and M30: clues of a non-standard IMF?
• The HST large programme on omega Centauri -- IV. catalogue of two external fields
• JWST uncovers helium and water abundance variations in the bulge globular cluster NGC 6440
• Modelling the Observed Stellar Mass Function and its Radial Variation in Galactic Globular Clusters
• Detection of multiple stellar populations in extragalactic massive clusters with JWST
• A JWST project on 47 Tucanae. Binaries among multiple populations