Abstract
Abstract
We study the evolution of the red and blue galaxies from
z=3 to z=0 using the EAGLE simulation. The galaxies in the blue
cloud and the red sequence are separated at each redshift using a
scheme based on Otsu's method. Our analysis shows that the two
populations have small differences in the local density and the
clustering strength until z=2, after which the red galaxies
preferentially occupy the denser regions and exhibit a significantly
stronger clustering than the blue galaxies. The
significant disparities in cold gas mass and specific star
formation rate (sSFR) observed before z=2 suggest that factors
beyond environmental influences may also contribute to the
observed dichotomy. Interacting galaxy pairs at a given
separation exhibit a higher SFR at increasing redshifts, which may
be linked to the rising gas fractions at higher redshift. As
redshift decreases, the SFR decreases across all separations,
suggesting a gradual depletion of the cold gas
reservoir. At pair separations < 50 kpc, an
anomalous increase in the SFR among paired galaxies in isolation
around z ~ 2 suggests that environmental effects begin to
dominate at this redshift, thereby increasing the rate of galaxy
interactions and the occurrence of starburst galaxies. We observe
a substantial decrease in the blue fraction in paired galaxies
starting from z=1 to the present. However, the decrease in the
blue fraction in paired galaxies with their second nearest neighbour
at a distance greater than 500 kpc continues until z=0.5, after
which the blue fraction begins to increase.