Revisiting the relation between the number of globular clusters and galaxy mass for low mass galaxies

Abstract

Using a new method to estimate total galaxy mass (M${}_{\mathrm{T}}$) and two samples of low luminosity galaxies containing measurements of the number of globular clusters (GCs) per galaxy (N${}_{\mathrm{GC}}$), we revisit the N${}_{\mathrm{GC}}-$M${}_{\mathrm{T}}$ relation using a total of 203 galaxies, 157 of which have M${}_{\mathrm{T}}$ $\le 10^{10}$ M${}_{\odot }$. We find that the relation is nearly linear, N${}_{\mathrm{GC}}\propto$ M${}_{\mathrm{T}}^{0.92\pm 0.08}$ down to at least M${}_{\mathrm{T}}\sim 10^{8.75}$ M${}_{\odot }$. Because the relationship extends to galaxies that average less than one GC per galaxy and to a mass range in which mergers are relatively rare, the relationship cannot be solely an emergent property of hierarchical galaxy formation. The character of the radial GC distribution in low mass galaxies, and the lack of mergers at these galaxy masses, also appears to challenge models in which the GCs form in central, dissipatively concentrated high-density, high-pressure regions and are then scattered to large radius. The slight difference between the fitted power-law exponent and a value of one, leaves room for a shallow M${}_{\mathrm{T}}$-dependent variation in the mean mass per GC that would allow the relation between total mass in GCs and M${}_{\mathrm{T}}$ to be linear.

Accepted for publication in MNRAS (6 pages, 3 figures)

References in corpus (16)

• galpy: A Python Library for Galactic Dynamics
• A High Stellar Velocity Dispersion and ~100 Globular Clusters for the Ultra Diffuse Galaxy Dragonfly 44
• Color--Mass-to-Light Ratio Relations for Disk Galaxies
• Galactic Dark Matter Halos and Globular Cluster Populations. III: Extension to Extreme Environments
• The PAndAS view of the Andromeda satellite system - II. Detailed properties of 23 M31 dwarf spheroidal galaxies
• Extensive Globular Cluster Systems Associated with Ultra Diffuse Galaxies in the Coma Cluster
• Dark Matter Halos in Galaxies and Globular Cluster Populations
• ELVES I: Structures of Dwarf Satellites of MW-like Galaxies; Morphology, Scaling Relations, and Intrinsic Shapes
• Globular Clusters in Coma Cluster Ultra Diffuse Galaxies (UDGs): Evidence for Two Types of UDG?
• Toward Equations of Galactic Structure
• Implications for Galaxy Formation Models from Observations of Globular Clusters around Ultra-Diffuse Galaxies
• Globular Clusters and Dark Satellite Galaxies through the Stream Velocity
• Clues to the nature of ultra diffuse galaxies from estimated galaxy velocity dispersions
• Clearing the hurdle: The mass of globular cluster systems as a function of host galaxy mass
• Local Group Dwarf Galaxies and the Fundamental Manifold of Spheroids
• An expanded catalogue of low surface brightness galaxies in the Coma cluster using Subaru/Suprime-Cam