The James Webb Space Telescope has captured a group of massive galaxies ending their growth due to supermassive black holes about 11 billion light years away

Galaxy clusters—the big cities of the universe—are home to many giant elliptical galaxies that have completed their growth and are not forming stars. However, it is still unclear what has shut down star formation. In a new study, researchers utilized the James Webb Space Telescope to observe an ancestor of galaxy clusters, revealing the role of supermassive black holes in slowing star formation and allowing them to evolve into giant elliptical galaxies.

Understanding how galaxies form and complete their growth is an area of fundamental focus in astrophysics. The dense regions of the universe, like galaxy clusters, are　dominated by giant elliptical galaxies—massive, ancient galaxies that consist of old stars. Although the mechanism by which these giant elliptical galaxies halt star formation remains debated, one theory predicts that supermassive black holes (SMBHs) could play a key role. Their intense energy can suppress the gas supply to galaxies, which may lead to the formation of the giant elliptical galaxies seen today.

Against this backdrop, an international team of researchers investigated massive galaxies in an ancient galaxy cluster known as the Spiderweb protocluster, located 11 billion light years away (Fig. 1), using data from the James Webb Space Telescope (JWST). The research was led by Associate Professor Rhythm Shimakawa from Waseda University, Japan; Dr. Yusei Koyama from the National Astronomical Observatory of Japan; Prof. Tadayuki Kodama from Tohoku University, Japan; Dr. Helmut Dannerbauer and Dr. J. M. Perez-Martinez from the Instituto de Astrofísica de Canarias and Universidad de La Laguna, Spain; along with others who were a part of the team. Their findings were published in the Monthly Notices of the Royal Astronomical Society: Letters on December 18, 2024.

The team succeeded in obtaining high-resolution maps of the recombination lines of hydrogen, which indicate the activity of star formation and SMBHs, through the Near-Infrared Camera mounted on JWST. Detailed analysis showed that massive galaxies with active SMBHs exhibit no sign of star formation, meaning that their growth is severely hampered by SMBHs (Fig. 2). The results support the theoretical prediction that the formation of giant elliptical galaxies is linked with SMBH activity in the past.

“The Spiderweb protocluster has been studied by our team for more than 10 years using the Subaru Telescope and other facilities. With the new JWST data, we are now able to ‘answer the questions’ of understanding and predicting galaxy formation that we have accumulated,” remarks Dr. Shimakawa. He adds further, “This study marks a significant step forward in expanding our understanding of the co-evolution of SMBHs and galaxies in celestial cities.”

***

Reference
DOI: https://doi.org/10.1093/mnrasl/slae098

Title of original paper: Spider-Webb: JWST Near Infrared Camera resolved galaxy star
formation and nuclear activities in the Spiderweb protocluster at z = 2.16

Journal: Monthly Notices of the Royal Astronomical Society: Letters

Authors: Rhythm Shimakawa^1,2, Yusei Koyama^3,4,5, Tadayuki Kodama⁶, Helmut Dannerbauer^7,8, J. M. Pérez-Martínez^7,8, Huub J. A. Röttgering⁹, Ichi Tanaka⁴, Chiara D’Eugenio^7,8, Abdurrahman Naufal⁵, Kazuki Daikuhara⁶, and Yuheng Zhang^7,8,10,11

Affiliations:
¹Waseda Institute for Advanced Study (WIAS), Waseda University, Japan
²Center for Data Science, Waseda University, Japan
³National Astronomical Observatory of Japan (NAOJ), National Institutes of Natural Sciences, Japan
⁴Subaru Telescope, National Astronomical Observatory of Japan, National Institutes of Natural Sciences, Japan
⁵Department of Astronomical Science, The Graduate University for Advanced Studies, Japan
⁶Astronomical Institute, Tohoku University, Japan
⁷Instituto de Astrofísica de Canarias, Spain
⁸Universidad de La Laguna, Dpto. Astrofísica, Spain
⁹Leiden Observatory, Leiden University, the Netherlands
¹⁰Purple Mountain Observatory, Chinese Academy of Sciences, China
¹¹School of Astronomy and Space Science, University of Science and Technology of China, China

About Waseda University
Located in the heart of Tokyo, Waseda University is a leading private research university that has long been dedicated to academic excellence, innovative research, and civic engagement at both the local and global levels since 1882. The University has produced many changemakers in its history, including nine prime ministers and many leaders in business, science and technology, literature, sports, and film. Waseda has strong collaborations with overseas research institutions and is committed to advancing cutting-edge research and developing leaders who can contribute to the resolution of complex, global social issues. The University has set a target of achieving a zero-carbon campus by 2032, in line with the Sustainable Development Goals (SDGs) adopted by the United Nations in 2015.

To learn more about Waseda University, visit https://www.waseda.jp/top/en

About Associate Professor Rhythm Shimakawa
Rhythm Shimakawa is currently an Associate Professor at the Waseda Institute for Advanced Study (WIAS) and Center for Data Science at Waseda University. He obtained his Ph.D. from Osaka University in 2012. Before joining Waseda University, he was a NAOJ fellow of the National Astronomical Observatory of Japan (NAOJ). He has published over 100 articles that have received over 1,800 citations. His research interests include galaxy formation and evolution, data astronomy, and galaxy–black hole co-evolution, among others.