Astrophysicists from Penn State, in collaboration with an international team of researchers, have discovered the second- and fourth-most distant galaxies ever observed using data from NASA’s James Webb Space Telescope (JWST). The galaxies were identified in an area of space known as Pandora’s Cluster or Abell 2744. By analyzing new spectroscopic data obtained from JWST, the scientists were able to confirm the distance and infer the properties of these ancient galaxies. Situated nearly 33 billion light years away, these galaxies provide valuable insights into the formation of early galaxies.

According to the researchers, unlike other galaxies observed at this distance, which appear as red dots, these newly discovered galaxies are larger in size and have distinctive shapes. One appears elongated, resembling a peanut, while the other has a fluffy ball-like appearance. These variations in shape raise questions about the formation and evolution of galaxies during the early stages of the universe.

Studying such distant galaxies is crucial for expanding our understanding of the early universe, its formation, and the growth of galaxies. Bingjie Wang, the first author of the study and a member of the JWST UNCOVER team at Penn State, emphasizes the significance of these findings in illuminating the complexities of the early universe. Prior to this research, only three galaxies had been confirmed at similar extreme distances. The discovery of these new galaxies highlights the diversity of galaxies in the early universe and the vast amount of knowledge they can offer.

The immense distance between these galaxies and Earth allows scientists to observe light that has traveled for billions of years, providing a window into the past. The light emitted by these galaxies was estimated to have been present when the universe was approximately 330 million years old. It has taken around 13.4 billion years for this light to reach JWST. However, due to the expansion of the universe over time, the galaxies are currently located around 33 billion light years away from Earth.

Joel Leja, an assistant professor of astronomy and astrophysics at Penn State, emphasizes the age of the light detected from these galaxies. It is approximately three times older than Earth, signifying their immense antiquity. Leja refers to the early galaxies as “beacons,” through which we can understand the physics that governed galaxies during the cosmic dawn.

Notably, the two newly discovered galaxies are considerably larger than the previously observed galaxies at extreme distances. One of them is at least six times larger, measuring around 2,000 light years across. This size difference raises questions about the factors that influenced the galaxies’ growth and shape.

The discovery of these distant galaxies was made possible by JWST’s advanced infrared instruments and the phenomenon known as gravitational lensing. Located behind galaxy clusters, this region of space experiences gravitational magnification, causing light to bend and magnify as it passes through. This magnification enhances the researchers’ ability to detect and study distant objects.

The UNCOVER team used a combination of data analysis and spectroscopy to narrow down approximately 60,000 light sources in Pandora’s Cluster to 700 candidates. Among these candidates, eight were identified as potential early galaxies. Subsequent observations by JWST confirmed the presence of two ancient galaxies. However, the team acknowledges that their observations represent only a small fraction of the region, and there may be more distant galaxies that will be unveiled by future observations.

The properties of the two galaxies were inferred using detailed models. The analysis revealed that these galaxies were young, had a low metal composition, and were actively forming stars. These characteristics align with the fundamental understanding of the early universe and further support the Big Bang theory.

As JWST continues its mission, the hope is that it will uncover galaxies even further away. However, the researchers acknowledge the limitations of their observation window and the possibility that galaxies may not have formed before the time period studied thus far. Further exploration and observations will help refine our understanding of the early universe and the formation of galaxies.

The successful discovery of these ancient galaxies was made possible by a collaborative effort involving various institutions and organizations worldwide. NASA, the United States-Israel Binational Science Foundation, the U.S. National Science Foundation, and numerous other entities provided support for this research.

The scientists involved in this study expressed their excitement and gratitude for the opportunity to utilize JWST’s capabilities during its first year of scientific operations. Despite the pressure and logistical challenges involved in coordinating observations, the team was able to make groundbreaking discoveries that contribute to our knowledge of the early universe and the formation of galaxies.

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