Multiple stellar population mass loss in massive Galactic globular clusters

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Lacchin, Elena, Mastrobuono-Battisti, Alessandra, Calura, Francesco, Nipoti, Carlo, Milone, Antonino P., Meneghetti, Massimo, Vanzella, Eros
Format: Preprint
Published: 2023
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866911752247050240
author Lacchin, Elena
Mastrobuono-Battisti, Alessandra
Calura, Francesco
Nipoti, Carlo
Milone, Antonino P.
Meneghetti, Massimo
Vanzella, Eros
author_facet Lacchin, Elena
Mastrobuono-Battisti, Alessandra
Calura, Francesco
Nipoti, Carlo
Milone, Antonino P.
Meneghetti, Massimo
Vanzella, Eros
contents The degree of mass loss, i.e. the fraction of stars lost by globular clusters, and specifically by their different populations, is still poorly understood. Many scenarios of the formation of multiple stellar populations, especially the ones involving self-enrichment, assume that the first generation (FG) was more massive at birth than now to reproduce the current mass of the second generation (SG). This assumption implies that, during their long-term evolution, clusters lose around $90\%$ of the FG. We have tested whether such strong mass loss could take place in a massive globular cluster orbiting the Milky Way at $4\ {\rm kpc}$ from the centre and composed of two generations. We perform a series of $N$-body simulations for ${12\ \rm Gyr}$ to probe the parameter space of internal cluster properties. We have derived that, for an extended FG and a low-mass second one, the cluster loses almost $98\%$ of its initial FG mass and the cluster mass can be as much as 20 times lower after a Hubble time. Furthermore, under these conditions, the derived fraction of SG stars, $f_{\rm enriched}$, falls in the range occupied by observed clusters of similar mass ($\sim 0.6-0.8$). In general, the parameters that affect the most the degree of mass loss are the presence or not of primordial segregation, the depth of the central potential, $W_{0,FG}$, the initial mass of the SG, $M^{ini}_{SG}$, and the initial half-mass radius of the SG, $r_{h,SG}$. Higher $M^{ini}_{SG}$ have not been found to imply higher final $f_{\rm enriched}$ due to the deeper cluster potential well which slows down mass loss.
format Preprint
id arxiv_https___arxiv_org_abs_2309_15161
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Multiple stellar population mass loss in massive Galactic globular clusters
Lacchin, Elena
Mastrobuono-Battisti, Alessandra
Calura, Francesco
Nipoti, Carlo
Milone, Antonino P.
Meneghetti, Massimo
Vanzella, Eros
Astrophysics of Galaxies
The degree of mass loss, i.e. the fraction of stars lost by globular clusters, and specifically by their different populations, is still poorly understood. Many scenarios of the formation of multiple stellar populations, especially the ones involving self-enrichment, assume that the first generation (FG) was more massive at birth than now to reproduce the current mass of the second generation (SG). This assumption implies that, during their long-term evolution, clusters lose around $90\%$ of the FG. We have tested whether such strong mass loss could take place in a massive globular cluster orbiting the Milky Way at $4\ {\rm kpc}$ from the centre and composed of two generations. We perform a series of $N$-body simulations for ${12\ \rm Gyr}$ to probe the parameter space of internal cluster properties. We have derived that, for an extended FG and a low-mass second one, the cluster loses almost $98\%$ of its initial FG mass and the cluster mass can be as much as 20 times lower after a Hubble time. Furthermore, under these conditions, the derived fraction of SG stars, $f_{\rm enriched}$, falls in the range occupied by observed clusters of similar mass ($\sim 0.6-0.8$). In general, the parameters that affect the most the degree of mass loss are the presence or not of primordial segregation, the depth of the central potential, $W_{0,FG}$, the initial mass of the SG, $M^{ini}_{SG}$, and the initial half-mass radius of the SG, $r_{h,SG}$. Higher $M^{ini}_{SG}$ have not been found to imply higher final $f_{\rm enriched}$ due to the deeper cluster potential well which slows down mass loss.
title Multiple stellar population mass loss in massive Galactic globular clusters
topic Astrophysics of Galaxies
url https://arxiv.org/abs/2309.15161