How the Roman Space Telescope could unveil galactic history

The Nancy Grace Roman Space Telescope, planned for launch by NASA, could significantly advance our understanding of galactic formation history through its ability to combine high-resolution infrared imaging and with an expansive field of view. This field allows Roman to efficiently survey vast portions of the sky, capturing billions of galaxies across cosmic history.

The proposed Roman Infrared Nearby Galaxies Survey (RINGS) aims to capitalize on this capability by developing open-source tools for community use. Roman’s expansive field of view (200 times larger than Hubble’s in the infrared) coupled with comparable resolution to Hubble enables efficient large-scale galactic surveys, complementing Hubble’s detailed, narrower field observations.

Studying galactic evolution

Understanding galactic evolution offers a window into the universe’s past, providing glimpses into the processes that shaped galaxies like our own Milky Way. By studying the formation and evolution of galaxies, we gain a deeper understanding of the distribution of matter, the role of dark matter, and the overall cosmic timeline.

The study of stellar halos offers a unique perspective on galactic evolution. Current limitations in obtaining spatially resolved stellar halo data restrict comprehensive analysis to a small number of nearby galaxies. The Roman Space Telescope could expand this dataset significantly, potentially enabling the characterization of stellar halos in over 100 galaxies. This data from the telescope promises to refine our understanding of galactic formation and the distribution of dark matter.

Next steps

The Roman Space Telescope is slated for a May 2027 launch. While the telescope’s primary mission is established, the RINGS survey highlights its potential for future investigations. The survey’s focus on nearby galaxies similar in size and age to the Milky Way could provide comparative data, offering potentially new data on our own galaxy’s formation and characteristics. This approach is especially valuable given the challenges of observing the Milky Way from within it.