New Study Reveals How Environment Shapes Galaxy Growth

New research has unveiled how the growth of galaxies is intricately linked to their surrounding environments. The findings, released by the Deep Extragalactic Visible Legacy Survey (DEVILS), a collaboration between the International Centre for Radio Astronomy Research (ICRAR) and the University of Western Australia, provide an extensive dataset that offers insights into galaxy evolution over the past five billion years.

The first data release from DEVILS, published in the Monthly Notices of the Royal Astronomical Society, includes comprehensive catalogues featuring morphological, redshift, photometric, and spectroscopic data. It encompasses thousands of galaxies, detailing their group environments and halo data. The study, led by Luke Davies, an Associate Professor at the University of Western Australia, is the culmination of a decade of dedicated observations and analysis.

Understanding Galaxy Development Through New Data

Unlike other astronomical surveys, DEVILS specifically targets galaxies that existed during a critical period in cosmic history, allowing researchers to compare these older galaxies with their modern counterparts. This unprecedented perspective aids astronomers in understanding how galaxies have transformed over time.

Davies remarked, “While previous surveys during this period of universal history have explored the broad evolution of galaxy properties, they have inherently lacked the capacity to determine the finer details of the cosmic landscape.” The DEVILS survey refines this approach by mapping out the small-scale environments of galaxies, identifying features akin to mountains, hills, and valleys, in contrast to larger-scale environments like oceans or continents.

A significant finding from the study indicates that galaxies in crowded environments tend to develop more slowly than their isolated counterparts. The researchers categorize galaxies into two main groups: blue, gas-rich, star-forming systems, and red, gas-poor, quiescent systems with minimal ongoing star formation. As the universe evolves, the proportion of quiescent systems increases.

In densely populated environments, such as galaxy clusters or pairs, the supply of cold gas essential for star formation can be disrupted or removed. The researchers identify several mechanisms, including ram-pressure stripping and tidal interactions, that contribute to this phenomenon, ultimately inhibiting star formation in certain galaxies.

Galaxies as Reflections of Their Environments

Davies draws an analogy between galaxies and human beings, stating, “Our upbringing and environment influence who we are. Someone who has lived their whole life in the city may have a very different personality compared to someone who lives remotely or in an isolated community. Galaxies are no different.” This perspective underscores the profound impact of environmental factors on galaxy structure and growth.

The DEVILS dataset will not only advance the current understanding of galaxy formation but also serve as a resource for other researchers in the field. Future expansions of the survey are already in the works, with plans to initiate the Wide Area VISTA Extragalactic Survey (WAVES) next year. This new project aims to broaden the scope of research by investigating a greater number of galaxies and environments, contributing to a clearer picture of the universe’s evolution.

Davies states, “DEVILS forms the basis of our future plans in exploring this key area of astrophysics research. It has given us a detailed picture of galaxy evolution.” As scientists continue to delve into the complexities of galaxy formation, studies like DEVILS play a crucial role in unraveling the mysteries of the cosmos.