Supermassive black-hole growth (IMAGE) Penn State Caption Researchers have provided the best modeling to date of the growth of the supermassive black holes found in the centers of galaxies by combining X-ray observations from the most powerful X-ray facilities ever launched into space with supercomputer simulations of the buildup of galaxies over cosmic history. On the left is an image combining X-ray (blue) and optical (red, green, and blue) observations and on the right is simulated gas column density from cosmological simulations using IllustrisTNG. The observed X-ray emission is mainly from accreting supermassive black holes, as depicted in the artist’s illustration (inset). The length of the short-side of the figure covers the same apparent size as the full Moon in the sky. Credit F. Zou (Penn State) et al.; Observations: The XMM-SERVS Collaboration; Simulations: The TNG Collaboration;Illustration: Nahks TrEhnl (Penn State) Usage Restrictions Credit must be given to the creator. Only noncommercial uses of the work are permitted. No derivatives or adaptations of the work are permitted. License CC BY-NC-ND Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.