“The globular cluster - dark halo connection”
Globular cluster systems show a fascinating and very tight, linear correlation with the dark matter halo mass of their hosts. To very high precision the total halo mass is equal to the number of globular clusters times 5e9 Msolar. This puzzling correlation extends over 8 orders of magnitudes in halo masses from dwarf galaxies to galaxy clusters. It is ideally suited in order to determine halo masses from globular cluster counts. Due to its extremely small spread, this correlation also allows to estimate the errors in determining halo masses from kinematical tracers or weak lensing which turn out to be a factor of 2.
I will discuss current ideas on the origin of this correlation which provide important insight into globular cluster formation in the early universe as well as the growth of dark matter halos and galaxy assembly in general.