Turning Back the Cosmic Clock: How NASA's Novel Space Telescope Will Turn Back the Universe

Through its ability to rapidly image vast swathes of space, Roman will help us understand how the universe changed from the Julian water of charged particles to the complex network of large cosmic structures we see today.

A new visualization shows how NASA's Nancy Grace Roman Space Telescope, to be launched in May 2027, will turn back the cosmic clock and reveal the evolving universe in ways never before possible. Through his ability to rapidly image vast swathes of space, Roman will help us understand how the universe changed from the Julian water of charged particles to the complex web of large cosmic structures we see today.

"The Hubble and James Webb space telescopes are optimized to study astronomical objects deeply and closely, so they look at the world through pinholes," said Aaron Jung, a postdoctoral researcher at NASA's Goddard Space Flight Center in Greenbelt, Maryland, who led the study. "To solve cosmic mysteries on the largest scale, you need a telescope that can provide a much larger view. This is exactly what Roman is designed to do."

The combination of Roman's large view with Hubble's wider wavelength coverage and Webb's more detailed observations will allow for a more comprehensive view of the universe.

The simulation covers a two-square-degree patch of sky, which is roughly ten times the apparent size of a full moon, and contains more than five million galaxies. It is based on a very well-established model of galaxy formation that represents our current understanding of how the universe works. Using a very efficient technique, the team can simulate tens of millions of galaxies in less than a day - compared to years with the usual methods. When Roman launches and starts sending real data, the scientists will be able to compare it to a variety of such simulations, putting their models to the ultimate test. This will help solve the physics of galaxy formation, dark matter - a mysterious substance that can only be observed through its gravitational effects - and many other things.

A paper describing the results was published in the December 2022 Monthly Notices of the Royal Astronomical Society.

Galaxies and galaxy clusters glow in clumps along invisible filaments of dark matter in a carpet the size of the observable universe. Taking a wide enough view of this tapestry, we can see that the large-scale structure of the universe resembles a web, with strands stretching across hundreds of millions of light-years. Galaxies are mostly found at intersection points of the filaments, with "empty cosmic spaces" between all the glowing filaments.

This is what the universe looks like today, but if we could rewind the universe, we would see something very different.

Instead of huge burning stars sparsely scattered in galaxies separated by even greater distances, we find ourselves immersed in a sea of ​​plasma (charged particles). This July soup was almost completely uniform, but luckily there were tiny knots. These clumps were slightly thicker than their surroundings, so their gravitational pull was slightly greater.

Over hundreds of millions of years, the clumps attracted more and more material to them. They grew large enough to form stars, which gravity pulled them into the dark matter that forms the invisible backbone of the universe. Galaxies were born and continued to evolve, and eventually planetary systems like our solar system appeared.

Roman's panoramic view will help us see what the universe was like at different stages and fill in gaps in our understanding. For example, astronomers have discovered "halos" of dark matter that surround galaxies, but they are not sure how they formed. By showing how dark matter-induced gravitational clouding envelops the appearance of more distant objects, Roman will help us see how haloes have evolved over cosmic time.

More of the topic in Hayadan:

• Higher, farther, earlier - scientists discovered a galaxy from the beginning of the universe
• Is a large concentration of dark energy at the beginning of the universe responsible for accelerating the expansion of the universe that began 7 billion years ago and is felt today?
• The race for matter since the beginning of the universe