On the weak lensing masses of a new sample of galaxy groups
  Galaxy group masses are important to relate these systems with the dark
matter halo hosts. However, deriving accurate mass estimates is particularly
challenging for low-mass galaxy groups. Moreover, calibration of bservational
mass-proxies using weak-lensing estimates have been mainly focused on massive
clusters. We present here a study of halo masses for a sample of galaxy groups
identified according to a spectroscopic catalogue, spanning a wide mass range.
The main motivation of our analysis is to assess mass estimates provided by the
galaxy group catalogue derived through an abundance matching luminosity
technique. We derive total halo mass estimates according to a stacking
weak-lensing analysis. Our study allows to test the accuracy of mass estimates
based on this technique as a proxy for the halo masses of large group samples.
Lensing profiles are computed combining the groups in different bins of
abundance matching mass, richness and redshift. Fitted lensing masses correlate
with the masses obtained from abundance matching. However, when considering
groups in the low- and intermediate-mass ranges, masses computed according to
the characteristic group luminosity tend to predict higher values than the
determined by the weak-lensing analysis. The agreement improves for the
low-mass range if the groups selected have a central early-type galaxy.
Presented results validate the use of mass estimates based on abundance
matching techniques which provide good proxies to the halo host mass in a wide
mass range.
