Supergiants and their shells in young globular clusters

摘要: Anomalous surface abundances are observed in a fraction of the low-mass stars Galactic globular clusters, that may originate from hot-hydrogen-burning products ejected by previous generation massive stars. We present and investigate scenario which second polluted can form shells around cool supergiant within young cluster. Simulations low-Z (M$_{\rm i}\sim$ 150$-$600 M$_{\odot}$) show both core-hydrogen-burning supergiants hot ionizing stellar sources expected to be simulaneously clusters. Under these conditions, photoionization-confined supergiants. find shell is gravitationally unstable on timescale shorter than lifetime supergiant, Bonnor-Ebert mass overdense regions low enough allow star formation. Since formed this made up material lost its composition necessarily reflects wind. wind contains products, shell-stars therefore have very similar abundance anomalies Considering mass-budget required for star-formation, we offer two solutions. Either top-heavy initial function needed with an index $-$1.71..$-$2.07. Alternatively, suggest truncated distribution, solve budget problem justifiably accounting only first generation. Even without forming photoionizaton-confined shell, predicted at could contribute pollution interstellar medium cluster was born.