Science T6: Environment
We explore three different environments with PROFUSE: galaxy mergers and interactions (< 100 kpc scales, Topic 6A), the galaxy density field (~ 1-2 Mpc scales, Topic 6B), and virialised structures (groups and clusters, Topic 6C).
The merger history of a given population is estimated measuring its merger fraction fm, i.e., the fraction of galaxies in a sample suffering a merging process, both by morphological criteria (highly distorted galaxies are merger remnants) and by close pair statistics (two galaxies close in the sky plane and in redshift space, Dv ≤ 500 km/s, that will lead to a merger).
The galaxy density field has been profusely used to study the impact of environment in galaxy properties, such as the luminosity, the colour, the stellar mass, or the star formation rate. Thus, a robust and unbiased estimation of the density field is needed to track the role of environment from z = 1 to the local Universe.
Groups and clusters are the densest structures in the Universe and are tightly linked with the underlying dark matter (DM) distribution. Thus, they are ideal laboratories for galaxy and cosmological studies and complement the merger and the density field environments.