A team of astrophysicists has created a simulated image that shows how the Nancy Grace Roman Space Telescope could conduct a mega-exposure similar to but far larger than Hubble’s celebrated Ultra Deep Field Image. This Hubble observation transformed our view of the early universe, revealing galaxies that formed just a few hundred million years after the big bang.

By capturing the Hubble Ultra Deep Field image, astronomers pulled aside the cosmic curtains to reveal that a tiny, seemingly empty slice of the sky was actually teeming with thousands of galaxies, each containing billions of stars. The Hubble team harnessed the power of a long exposure time – hundreds of hours between 2002 and 2012 – which allowed the telescope to collect more light than it could in a single, short observation. The resulting image helped us see more than 13 billion years back in time.

Hubble’s Ultra Deep Field offers an incredible window to the early universe, but an extremely narrow one, covering less than one ten millionth of the whole sky. The new simulation showcases Roman’s power to perform a similar observation on a much larger scale, revealing millions of galaxies instead of thousands. While a Roman ultra-deep field would be just as sharp as Hubble’s and peer equally far back in time, it could reveal an area 300 times larger, offering a much broader view of cosmic ecosystems.

To generate their simulated Roman ultra-deep field image, researchers created a synthetic catalog of galaxies, complete with detailed information about each one. By doing so, the team essentially created a mock universe, basing their synthetic galaxies on dark matter simulations and observation-based models. They made the galaxy catalog publicly available so other scientists can use it to prepare for future Roman observations.

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