New findings from the Deep Extragalactic Visible Legacy Survey (DEVILS) indicate that the growth of galaxies is significantly influenced by their surrounding environments. This research, led by Luke Davies, an Associate Professor at the University of Western Australia and a key member of the International Centre for Radio Astronomy Research (ICRAR), provides critical insights into how galaxies evolve over time. The first data release from DEVILS includes extensive catalogues of morphological, redshift, photometric, and spectroscopic data for thousands of galaxies, highlighting their group environments and dark matter haloes.
The findings are detailed in a study published in the Monthly Notices of the Royal Astronomical Society. Titled “Deep Extragalactic VIsible Legacy Survey (DEVILS): first data release covering the D10 (COSMOS) region,” this publication marks a decade-long effort in astronomical observations and data analysis. Unlike other surveys that focus on contemporary galaxies, DEVILS investigates galaxies that existed up to five billion years ago, allowing researchers to trace their evolution.
Understanding Galaxy Evolution in Detail
Davies emphasized the uniqueness of DEVILS, which zooms in on the small-scale environments of galaxies, likening them to varied terrains such as mountains and valleys. He noted that while previous surveys have explored broad evolutionary trends, they often lacked the ability to assess the intricate details of the cosmic landscape. He stated, “In the DEVILS survey, we have been able to zoom in and focus on mapping out the small-scale environment of galaxies.”
One significant conclusion from the research is that galaxies situated in crowded environments tend to grow at a slower pace than their isolated counterparts. The study classifies galaxies into two primary types: blue, gas-rich, star-forming systems, and red, gas-poor, quiescent systems with minimal star formation. Over time, galaxies evolve from low-mass, blue systems into more quiescent forms as the universe ages.
The researchers found that in dense environments, such as galaxy clusters or groups, the supply of cold gas necessary for ongoing star formation is often disrupted. This disruption can lead to a phenomenon known as “quenching,” where star formation slows or ceases altogether. Mechanisms such as ram-pressure stripping and tidal interactions are identified as key factors that influence the movement of star-forming gas between galaxies, facilitating star formation in some while inhibiting it in others.
Implications for Future Research
Davies draws a parallel between galaxy evolution and human development, 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.”
The DEVILS data offers a wealth of information that will be beneficial for future research within the astronomical community. As Davies explains, “DEVILS forms the basis of our future plans in exploring this key area of astrophysics research.” The team is preparing to expand their investigation through the upcoming WAVES (Wide Area VISTA Extragalactic Survey), which aims to significantly increase the number of galaxies and environments studied, further enhancing our understanding of how the universe has evolved.
This pioneering research not only sheds light on the intricate processes that govern galaxy evolution but also sets the stage for future studies that will delve deeper into the complex dynamics of the cosmos. As the scientific community continues to analyze and interpret the DEVILS data, the findings promise to reshape our understanding of galaxies and their development over billions of years.
