Investigating the $M_{GCS}-M_h$ Relation in the Most Massive Galaxies

Understand

The relation between the total mass contained in the globular clusters of a galaxy and the mass of its dark matter halo has been found observationally to be nearly linear over five decades of mass.

• However, the high-mass end of this relation is not well determined from previous data and shows large scatter.
• We analyze the globular cluster systems (GCSs) of a homogeneous sample of 11 brightest cluster galaxies (BCGs) through DOLPHOT photometry of their deep Hubble Space Telescope (HST) images in the F814W filter.
• We standardize the definition of $M_{GCS}$, the total GCS mass, by using the GC total population within a limiting radius of $0.1 R_{virial}$, while the dark-matter halo mass $M_h$ is determined from the weak-lensing calibration of $M_h$ versus $M_{bary}$.