Washington, Dec 08: A combined study by French and Italian astronomers has revealed that Darwin’s theory that environment strongly influences evolution holds true for stars and galaxies as well.
Using VIMOS on European Space Organisation`s (ESO’s) Very Large Telescope, the team found that the distribution of galaxies had considerably evolved with time, depending on their immediate surroundings.
In a large, three-year long survey carried out with VIMOS, the Visible Imager and Multi-Object Spectrograph on ESO`s VLT, astronomers studied more than 6,500 galaxies over a wide range of distances to investigate how their properties vary over different timescales, in different environments and for varying galaxy luminosities.
The team built an atlas of the Universe in three dimensions, going back more than nine billion years and found that the colour-density relation that described the relationship between the properties of a galaxy and its environment, was markedly different seven billion years ago.
They found that the galaxies` luminosity, their initial genetic properties, and the environments they resided in, had a profound impact on their evolution.
"Our results indicate that environment is a key player in galaxy evolution, but there`s no simple answer to the `nature versus nurture` problem in galaxy evolution. They suggest that galaxies as we see them today are the product of their inherent genetic information, evolved over time, as well as complex interactions with their environments, such as mergers," said Olivier Le Fèvre from the Laboratoire d`Astrophysique de Marseille, France, who coordinates the VIMOS VLT Deep Survey team that made the discovery.
"Using VIMOS, we were able to use the largest sample of galaxies currently available for this type of study, and because of the instrument`s ability to study many objects at a time we obtained many more measurements than previously possible," added Angela Iovino, from the Brera Astronomical Observatory, Italy, another member of the team.
Researchers said the connection between galaxies` colour, luminosity and their local environment was not merely a result of primordial conditions `imprinted` during their formation.
“Just as for humans, galaxies` relationship and interactions could have a profound impact on their evolution,” Iovino said.