Abstract:
The small-scale environment characterized by the local density is known to play a crucial role
in deciding the galaxy properties but the role of large-scale environment on galaxy formation
and evolution still remain a less clear issue. We propose an information theoretic framework
to investigate the influence of large-scale environment on galaxy properties and apply it to the
data from the Galaxy Zoo project that provides the visual morphological classifications of ∼1
million galaxies from the Sloan Digital Sky Survey. We find a non-zero mutual information
between morphology and environment that decreases with increasing length-scales but persists
throughout the entire length-scales probed. We estimate the conditional mutual information
and the interaction information between morphology and environment by conditioning the
environment on different length-scales and find a synergic interaction between them that
operates up to at least a length-scales of ∼30 h−1 Mpc. Our analysis indicates that these
interactions largely arise due to the mutual information shared between the environments on
different length-scales.
