The ACS Survey of Galactic Globular Clusters. VIII. Effects of Environment on Globular Cluster Global Mass Functions

Paust, Nathaniel E. Q.; Reid, I. Neill; Piotto, Giampaolo; Aparicio, A.; Anderson, Jay; Sarajedini, Ata; Bedin, Luigi R.; Chaboyer, Brian; Dotter, Aaron; Hempel, Maren; Majewski, Steven; Marín-Franch, A.; Milone, Antonino; Rosenberg, A.; Siegel, Michael
Bibliographical reference

The Astronomical Journal, Volume 139, Issue 2, pp. 476-491 (2010).

Advertised on:
2
2010
Number of authors
15
IAC number of authors
3
Citations
98
Refereed citations
93
Description
We have used observations obtained as part of the Hubble Space Telescope/ACS Survey of Galactic Globular Clusters to construct global present-day mass functions for 17 globular clusters utilizing multi-mass King models to extrapolate from our observations to the global cluster behavior. The global present-day mass functions for these clusters are well matched by power laws from the turnoff, ≈0.8 M sun, to 0.2-0.3 M sun on the lower main sequence. The slopes of those power-law fits, α, have been correlated with an extensive set of intrinsic and extrinsic cluster properties to investigate which parameters may influence the form of the present-day mass function. We do not confirm previous suggestions of correlations between α and either metallicity or Galactic location. However, we do find a strong statistical correlation with the related parameters central surface brightness, μ V , and inferred central density, ρ0. The correlation is such that clusters with denser cores (stronger binding energy) tend to have steeper mass functions (a higher proportion of low-mass stars), suggesting that dynamical evolution due to external interactions may have played a key role in determining α. Thus, the present-day mass function may owe more to nurture than to nature. Detailed modeling of external dynamical effects is therefore a requisite for determining the initial mass function for Galactic globular clusters.
Related projects
Superposition of model of long-bar+3-kpc arm of López-Corredoira et al. (2026, A&A 708, A288) with the artistic representation of the annotated ‘Road Map to the Milky Way’ by NASA/JPL-Caltech/R. Hurt (SSC/Caltech) based on NASA’s Spitzer Space Telescope achievements.
Milky Way and Nearby Galaxies
The overall aim of the project is to study the morphology, stellar populations, kinematics and dynamics (including formation and evolution) of the Milky Way and its satellite galaxies and other Local Group galaxies. The project can be divided into two main lines: I. Structure of the Milky Way and nearby galaxies. The detailed study of the
Martín
López Corredoira