Exploring the Hickson Compact Group 44

SMITH CASTELLI, A. V.; FAIFER, F.; ESCUDERO, C.; GOMES, J. M. ; VEGA NEME, L.; GONZÁLEZ, N.

Garching bei Munich

Workshop; Fornax, Virgo, Coma et al.: Stellar Systems in High Density Environments; 2011

European Southern Observatory

The influence of the environment in the formation of the galaxies we see today is still a key question. The mechanisms involved an the moment at which they occur in the field or in clusters and groups of galaxies have not been clearly identified yet. In this context the study of stellar systems belonging to high and low density environments becomes relevant to provide clues about these important issues.In particular, the study of compact groups is interesting as their galaxy space density is similar to that found in the central regions of rich clusters. In addition, they show low velocity dispersions which allow to observe gravitational interactions in progress.The idea that globular clusters (GCs) harbour important clues in relation with the early stages of galaxy formation is a widely accepted concept. GCS are used today to trace the early history of galaxy formation processes. But, on the other hand, Hickson groups are excellent laboratories to test the influence of the environment on the GCs formation itself and how the continuous gravitational encounters modify their characteristics.In this context we present the first study of the globular clusterpopulation of galaxies in the Hickson compact group HCG 44, in order to investigate the effect of this high-density environment on the formation and evolution of globular cluster systems. This work is based on high quality multi-band photometry  performed by psf fiting on g´, r´, i´ and z´ deep images obtained with Gemini+GMOS. The total globular cluster population, specific frequency, integrated colour distribution and radial projected spatial profiles of the GCs belonging to the four galaxies present in the fields.