Dynamical estimate of post main sequence stellar masses in 47 Tucanae

TL;DR

This study uses mass segregation effects in 47 Tucanae's core to estimate stellar masses at various post main sequence stages, revealing minimal mass loss during RGB and potential contamination by blue stragglers.

Contribution

It introduces a dynamical method to estimate stellar masses in a globular cluster core based on radial distributions, providing new insights into stellar evolution and mass loss.

Findings

Mass remains constant from upper MS to HB.

Excludes >0.09M mass loss during RGB at 3σ.

AGB stars show possible contamination by more massive stars.

Abstract

We use the effects of mass segregation on the radial distribution of different stellar populations in the core of 47 Tucanae to find estimates for the masses of stars at different post main sequence evolutionary stages. We take samples of main sequence (MS) stars from the core of 47 Tucanae, at different magnitudes (i.e. different masses), and use the effects of this dynamical process to develop a relation between the radial distance (RD) at which the cumulative distribution reaches the 20th and 50th percentile, and stellar mass. From these relations we estimate the masses of different post MS populations. We find that mass remains constant for stars going through the evolutionary stages between the upper MS up to the horizontal branch (HB). By comparing RDs of the HB stars with stars of lower masses, we can exclude a mass loss greater than 0.09M during the red giant branch (RGB) stage at nearly the 3{\sigma} level. The slightly higher mass estimates for the asymptotic giant branch (AGB) are consistent with the AGB having evolved from somewhat more massive stars. The AGB also exhibits evidence of contamination by more massive stars, possibly blue stragglers (BSS), going through the RGB phase. We do not include the BSS in this paper due to the complexity of these objects, instead, the complete analysis of this population is left for a companion paper. The process to estimate the masses described in this paper are exclusive to the core of 47 Tuc.