Free Astronomy Magazine November-December 2024

36 NOVEMBER-DECEMBER 2024 ASTRO PUBLISHING conflicting results. Now, a new study using the Dark Energy Camera (DECam) points the way to both an explanation for these disparate ob- servations and also a logical frame- work to connect observation with theory. DECam was fabricated by the Department of Energy and is mounted on the U.S. National Sci- ence Foundation Víctor M. Blanco 4-meter Telescope at Cerro Tololo Inter-American Observatory in Chile, a Program of NSF NOIRLab. The study was led by Trystan Lam- bert, who completed this work as a PhD student at Diego Portales Uni- versity’s Institute of Astrophysical Studies in Chile and is now a post- doc at the University of Western Australia node at the International Centre for Radio Astronomy Re- search (ICRAR). Utilizing DECam’s massive field of view, the team con- ducted the largest on-sky area search ever around an early-Uni- verse quasar in an effort to measure the density of its environment by counting the number of surround- ing companion galaxies. For their investigation, the team needed a quasar with a well-de- fined distance. Luckily, quasar VIK Early-Universe quasar neighborhoods are indeed cluttered by NOIRLab − Josie Fenske Q uasars are the most lumi- nous objects in the Universe and are powered by mate- rial accreting onto supermassive black holes at the centers of galax- ies. Studies have shown that early- Universe quasars have black holes so massive that they must have been swallowing gas at very high rates, leading most astronomers to believe that these quasars formed in some of the densest environments in the Universe where gas was most avail- able. However, observational mea- surements seeking to confirm this conclusion have thus far yielded