Astronomers have recently observed a pair of galaxies in the process of merging approximately 12.8 billion years ago. These galaxies exhibit characteristics that indicate they will form a “monster galaxy,” one of the brightest types of objects in the Universe. This discovery is significant for understanding the early evolution of galaxies and black holes in the early Universe. Quasars, which are luminous objects powered by matter falling into supermassive black holes at the center of a galaxy, are thought to be triggered by the merger of two gas-rich galaxies. In this scenario, the gravitational interaction of the merging galaxies causes gas to fall towards the supermassive black hole, leading to quasar activity.
To test this theory, an international team of researchers led by Takuma Izumi utilized the ALMA radio telescope to study the earliest known pair of close quasars. These quasars were first identified by Yoshiki Matsuoka at Ehime University in Japan, using images from the Subaru Telescope. Positioned in the constellation Virgo, this pair of quasars existed in the first 900 million years of the Universe’s existence. The dimness of these quasars suggests they are still in the early stages of their evolution. The ALMA observations revealed that the host galaxies of these quasars are connected by a “bridge” of gas and dust, indicating that the galaxies are indeed in the process of merging.
Furthermore, the ALMA observations enabled the team to measure the amount of gas present in the two galaxies, which serves as the material for new star formation. The researchers discovered that the galaxies are rich in gas, suggesting that as the merger progresses, there will be a significant increase in star formation, known as a “starburst.” This combination of starburst activity and intense quasar activity is anticipated to result in the formation of a super-bright object known as a monster galaxy in the early Universe. By studying this merger and its subsequent impact on galaxy and black hole evolution, astronomers can gain valuable insights into the early stages of cosmic evolution.
This discovery of galaxies in the act of merging and the potential formation of a monster galaxy provides a rare opportunity to observe the cosmic processes that shape the Universe in its infancy. The detailed observations conducted using the ALMA radio telescope have shed light on the mechanisms that drive the formation of quasars and starburst galaxies in the early Universe. By studying the evolution of galaxies and black holes in this early epoch, scientists can better understand the factors that influence the growth and development of cosmic structures over billions of years. The merger of these two galaxies and the subsequent formation of a monster galaxy offer a unique window into the complex interplay of forces that govern the evolution of the Universe.
Overall, the discovery of a pair of merging galaxies with the potential to form a monster galaxy represents a significant advancement in our understanding of the early Universe. By studying the processes that drive quasar activity, star formation, and galaxy mergers in the early stages of cosmic evolution, astronomers can gain valuable insights into the formation and growth of cosmic structures over billions of years. The observations conducted using the ALMA telescope have provided crucial data on the gas content, structure, and evolution of these merging galaxies, offering a glimpse into the cosmic processes that shape the Universe from its earliest moments. Through continued research and observation, scientists hope to unravel the mysteries of galaxy and black hole evolution and uncover the underlying principles that govern the vast expanse of the cosmos.