Hubble images guide Roman telescope dark matter search

Gravitational lensing reveals hidden mass

Gravitational lensing occurs when gravity from a massive foreground object bends light from distant background galaxies. This phenomenon creates distorted arcs or complete rings around the foreground galaxy that act like a giant space lens. Astronomers study these distortions to determine the quantity and distribution of mass within the foreground system. The images show how precise alignment between foreground and background objects produces magnified views of faraway targets.

Roman will find more lenses

The Nancy Grace Roman Space Telescope sees primarily infrared light over a much larger field of view than Hubble. While Hubble provides better resolution for individual objects, Roman will capture many more lenses in its panoramic surveys. Researchers plan to use Hubble's high-resolution data to build AI tools that efficiently search for similar arcs in Roman images. If Roman identifies an interesting lens, teams may return to Hubble for follow-up observations using visible and ultraviolet capabilities.

Models test dark matter theories

Scientists intend to construct lens models to prove or dispel theories about cold dark matter distribution. The cold dark matter theory predicts small clumps between a million and a billion solar masses exist in these systems. In contrast, the dark matter halo of the Milky Way galaxy weighs around 1.3 trillion solar masses. Detecting small imperfections in galaxy arcs could reveal these previously undetected clumps and confirm current theoretical predictions.