Astronomers have recently made a groundbreaking discovery, observing the largest sample of galaxies ever documented, extending over 12 billion light years away. The James Webb Space Telescope (JWST) recently reached a monumental milestone. To say that it is an exciting time to be a galaxy formation theorist probably does not do justice to the gravity of this statement.
This recently assembled catalog—with the nearly catchy title of COSMOS-Web deep galaxy group catalog—now contains almost 1,678 galaxy groups or proto-clusters. This deep and broad database illustrates the most complete and rich sample of galaxy groups ever found. Researchers now have a window into structures that persisted from roughly 12 billion years ago until one billion years ago.
Galaxy groups typically have three to ~30 member galaxies. They give us clues and context for how a larger, denser cluster with potentially hundreds to thousands of galaxies comes together. And of course, just like humans, most of these galaxies are never alone. They are found in pairs or even larger ensembles, underscoring why investigating such cosmic broods is so essential.
The Local Group and Its Role
Our home galaxy, the Milky Way, is a member of a small group of galaxies known as the Local Group. This group contains the Andromeda galaxy and over 50 smaller galaxies. Learning about the Local Group gives us a comparative baseline for how galaxies are expected to behave in their groups.
As astronomers explore all the data gathered from the JWST, they’ll be able to compare what those early galaxy structures look like compared to more modern formations. This side-by-side comparison is important to bridge knowledge of how galaxy groups are still evolving today.
“When we look very deep into the universe, the galaxies have more irregular shapes and are forming many stars,” – Gozaliasl.
The observations indicate that as galaxies age, they tend to develop more symmetrical structures, such as elliptical or spiral shapes. This evolution speaks to how dynamic the process of galaxy formation truly is and can inform our understanding of some of the most important questions regarding our universe’s history.
Insights from Galaxy Groups
Galaxy groups have a key impact on the life cycles of galaxies, dictating the evolutionary paths that they take. The complex tidal and dynamical interactions that occur in these groups frequently drive mergers, causing dramatic changes in galaxy structure and morphology.
“Groups and clusters are really important because within them galaxies can interact and merge together, resulting in the transformation of galaxy structure and morphology. Studying these environments also helps us understand the role of dark matter, feedback from supermassive black holes, and the thermal history of the hot gas that fills the space between galaxies,” – Gozaliasl.
As astronomers continue to explore these complex interactions, they hope to piece together a fuller history of how cosmic structures formed. Understanding these processes is vital for elucidating how massive galaxies and larger structures in the universe have formed and grown over time.
The Future of Cosmic Exploration
The launch of the James Webb Space Telescope (JWST) has completely transformed our ability to observe distant galaxies and offered unprecedented insights into how they formed. The data gathered allows scientists to explore some of the earliest galaxies formed in the universe and understand their development over billions of years.
“We’re able to actually observe some of the first galaxies formed in the universe,” – Gozaliasl.
This new ability is a game-changer for research, empowering astronomers to answer some of the most intricate questions regarding how our universe has evolved. A cosmo-local universe researchers are studying data from the COSMOS-Web catalog. From this, they want to learn how groups of galaxies develop over time and further inform our knowledge of the universe’s past.
“Like humans, galaxies come together and make families,” – Gozaliasl.