Diluting the material forming the second generation stars in Globular Clusters: the contribution by unevolved stars

TL;DR

This paper explores whether unevolved stars can provide the necessary dilution of material to explain chemical anticorrelations in second-generation globular cluster stars, implying a much larger original cluster mass.

Contribution

It proposes a novel hypothesis that unevolved stars contribute to the dilution process, linking the primordial GC population to the field stars.

Findings

Unevolved stars losing 0.5-1% of their mass can supply enough diluting material.

Original proto-GCs were significantly more massive than current GCs.

The scenario suggests a strong connection between GC and field star populations.

Abstract

In this short communication we consider the possibility that stars less evolved than the polluters are the source of the dilution needed to explain the observed composition of second-generation globular cluster (GC) stars and the Na-O and Mg-Al anticorrelations. If these stars can lose 0.5-1% of their mass during the relevant epochs, there is enough diluting material to produce the observed anticorrelations. In this case, the original mass of proto-GCs was several tens times higher than the current mass of GCs. While not strictly impossible, this is a stringent hypothesis that needs more support. Should this scenario be found true, then the link between the primordial (first-generation) population in GC and the field population would be very strong.