The history of how stars and galaxies came to be and evolved into the present day remains a challenging astrophysical question, but new research brings us closer to understanding it. In a recent study led by Dr. Angela Adamo at Stockholm University, insights about young galaxies during the Epoch of Reionization have been revealed. Observations with the James Webb Space Telescope (JWST) of the galaxy Cosmic Gems arc (SPT0615-JD) have confirmed that the light of the galaxy was emitted 460 million years after the big bang. The galaxy is unique in that it is magnified through gravitational lensing, allowing the team to study smaller structures inside an infant galaxy for the first time.
The Epoch of Reionization marked a crucial time during the early Universe, where the matter transitioned from neutral to fully ionized. To study the earliest galaxies, one must look far away in space and observe objects at great distances. Gravitational lensing, where celestial bodies of high mass curve the path of light, allows astronomers to observe small details in objects far away. Galaxies build their stellar population through star formation, where star clusters play a significant role. The discovery of star clusters in a galaxy whose light has passed through a gravitational lens offers new insights into the formation of the first stars and galaxies.
The team used the Near Infrared Camera (NIRCam) onboard the JWST for their observations of the galaxy SPT0615-JD and discovered five young massive star clusters within it. Analysis of the light spectra emitted by the galaxy revealed that the clusters are gravitationally bound and have a higher stellar density than typical young star clusters in the local Universe. These clusters were formed recently, within 50 million years, and are smaller than globular clusters. By studying star clusters in young galaxies born shortly after the Big Bang, further understanding of how and where globular clusters are formed can be achieved.
Understanding the early Universe through studies of star clusters in young galaxies born shortly after the Big Bang is crucial in gaining knowledge about the formation of stars and galaxies in the earliest stages. The discoveries made by the team in this study add to our understanding of how stars in the earliest galaxies were born and shed light on the formation of globular clusters. In the future, the group plans to build a larger sample of similar galaxies to create demographics of cluster populations forming in the earliest galaxies. They also have an approved program for the next cycle of JWST observations to study the Cosmic Gems Arc galaxy and the recently discovered star clusters in further detail.
In conclusion, the research conducted by Dr. Angela Adamo and her team provides valuable insights into the formation of stars and galaxies in the early Universe. By studying young galaxies born shortly after the Big Bang, astronomers can gain a deeper understanding of how and where star clusters are formed and their role in the evolution of galaxies. The discoveries made through the observations with the JWST offer new perspectives on the mysteries of the early Universe, bringing us closer to unraveling the complex history of stars and galaxies. With future studies and observations, we may continue to expand our knowledge of the cosmos and the processes that shaped it.