Groundbreaking observations using the Dark Energy Camera (DECam) have shed new light on the dense environments surrounding early-universe quasars, challenging our understanding of these enigmatic cosmic entities.

Quasars: Bright Signals From The Distant Past
Quasars are the most energetic objects in the universe, largely due to their incredible gravitational pull, exerted by a large black hole at the core of galaxies. These cosmic lighthouses are known to reside in some of the densest pockets of the early universe, where quarry is ripe for them to dine on.
In particular, different observational surveys have hinted at mutually contradictory pictures of the neighborhoods in quasar space. That has changed with a new way of looking at quasar fields – the best ever study done by images from the Dark Energy Camera (DECam) that now provide more insight what is happening in these mysterious regions.
The Big Picture Imaged in Wide Field of DECam
The Dark Energy Camera (DECam), built by the Department of Energy, mounted on the U.S. National Science Foundation-funded Víctor M. Blanco 4-meter Telescope located in Chile at Cerro Tololo Inter-American Observatory is what allowed this new study to happen.
The research team made the most extensive on-sky area search around an early-universe quasar—which is also the map of its cosmic neighbourhood, thanks to DECam’s huge field of view—for the quasar VIK J2348-3054. The quasar was picked as its distance had previously been well-mapped from other observations with the Atacama Large Millimeter/submillimeter Array (ALMA).
DECam’s special narrowband filter allowed the team to detect a particular kind of light radiated by young galaxies in the process of forming stars called Lyman-alpha radiation. With this distribution of Lyman-alpha emitters already on their hands, the team was able to build a 3D map of how the quasar’s environment is spread out – and what they found was pretty astounding.
Conclusion
The results of this study provide an attractive solution to the inherent tension between previous observations and unlock further insight into the intricate connections between quasars and their host galaxies. Revealing the complex interplay within these newborn galaxies, this latest work provides a new understanding of how quasars influence the evolution of the Universe.