Year: 1997
Type: article
Abstract: The dynamical evolution of the globular cluster systems in external galaxies is estimated, based on the standard dynamical theory normalized to the Milky Way. Assuming the same initial luminosity function, we construct an intrinsic distribution of globular clusters resulting from an isolated, passive evolution over the Hubble time of the true initial distribution. The galactic environment changes this distribution primarily through tidal shocks and dynamical friction. Our model explains, on a quantitative basis, the observed differences between the inner and outer populations of globular clusters in the Galaxy, M31, and M87. We can further calculate the amount of apparent brightening of the peak of the luminosity function due to destruction of low-mass clusters. Comparing the corrected peak with the center of the intrinsic distribution, we obtain distance moduli to the galaxies. Using this method we find dm M31 = 24.03 ± 0.23 and dm M87 = 30.81 ± 0.17, as compared to the current best estimates using other methods ( dm M31 = 24.30 ± 0.20, dm M87 = 31.0 ± 0.1). This new method, coupled with Hubble Space T elescope observations, promises to provide an independent way of estimating distances to galaxies with recessional velocities ≲10,000 km s -1 , or d ≲ 100 h -1 Mpc. The surprising consistency of the predicted and observed distances supports our initial Ansatz that the mass functions of globular clusters in the three galaxies, spanning a wide range of masses, were universal at the birth of these systems.
Source: The Astrophysical Journal
DOI: 10.1086/304646
Authors: Jeremiah P. Ostriker, Oleg Y. Gnedin
Institution: Princeton University
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
Funder: National Science Foundation
OpenAlex ID: W2001186740