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Simulated Cosmic Images Pave the Way for NASA’s Upcoming Telescope

Scientists have unveiled a remarkable collection of over one million simulated images depicting the universe as it will appear through the upcoming Nancy Grace Roman Space Telescope. This extensive library serves as a crucial resource for researchers as they prepare to investigate the telescope’s diverse scientific objectives.

“Utilizing a supercomputer, we generated a synthetic universe, simulating billions of years of cosmic evolution and meticulously tracing the path of every photon from various celestial bodies to Roman’s detectors,” explained Michael Troxel, an associate professor of physics at Duke University. Troxel led this ambitious simulation effort. “This is the most extensive and realistic mock universe survey currently accessible.”

The initiative, known as OpenUniverse, leveraged the now-decommissioned Theta supercomputer at the Department of Energy’s Argonne National Laboratory in Illinois. This advanced computing system achieved what would typically be a 6,000-year computation in just nine days.

Alongside the Roman Telescope, the vast 400-terabyte dataset will also provide insights into observations from the Vera C. Rubin Observatory—funded collaboratively by the National Science Foundation and the U.S. Department of Energy—and preliminary simulations from the European Space Agency’s Euclid mission, which includes contributions from NASA. The Roman dataset is currently accessible here, with data from Rubin and Euclid expected to be available shortly.

The team incorporated advanced modeling of the universe’s fundamental physics while integrating information from existing galaxy catalogs and the anticipated performance of the telescopes. The simulated images cover a substantial area of 70 square degrees, roughly matching the sky region covered by over 300 full moons, and encapsulate more than 12 billion years of cosmic history.

This expansive simulation offers astronomers a valuable opportunity to address some of the most significant mysteries of the universe. Researchers aim to deepen their understanding of dark energy, the enigmatic force believed to be driving the universe’s accelerated expansion, and dark matter, which is detectable only through its gravitational influence on visible matter. By analyzing this dataset, scientists hope to gain insights into the nature of dark matter and its role in cosmic formation by studying its effects on visible matter. The simulation includes 100 million synthetic galaxies, providing a comprehensive perspective on the evolution of galaxies and clusters over time.

Using these repeated simulations, the scientists have crafted animated sequences that illustrate the violent antics of exploding stars, akin to fireworks illuminating the synthetic cosmos. These stellar explosions are crucial for mapping the universe’s expansion.

As researchers leverage OpenUniverse data, they aim to establish an alert system that will notify astronomers when the Roman Telescope detects such explosive events. This system will help track the emitted light, enabling focused studies on these phenomena.

Given the sheer volume of data that the Roman Telescope is expected to generate, scientists recognize the necessity of developing innovative machine-learning algorithms. These tools will assist in efficiently filtering through the massive influx of data, distinguishing various cosmic occurrences, including different classes of supernovae.

“One of the main challenges is differentiating between a specific type of supernova that is instrumental for mapping the universe’s expansion and other similar occurrences that do not contribute to that goal,” noted Alina Kiessling, a research scientist at NASA’s Jet Propulsion Laboratory and the principal investigator for OpenUniverse.

While Euclid is already operational, the Rubin Observatory is scheduled to commence its operations later this year, and the Roman Telescope is set to launch by May 2027. The synthetic images are invaluable for planning observations and prepping for the high volume of data anticipated from these new telescopes. This preparatory phase is critical due to the enormous data deluge they are poised to generate.

“The Roman mission will significantly surpass all previous space-based infrared and optical observations,” Troxel stated. “For one of Roman’s surveys, it will accomplish in under a year what would have taken the Hubble or James Webb Space Telescopes approximately a thousand years. The number of sharply imaged objects will be transformative.”

According to Kiessling, “We can expect a wealth of groundbreaking, potentially Nobel Prize-winning discoveries from Roman’s findings. The mission aims to reveal the history of the universe’s expansion, create three-dimensional maps of galaxies and galaxy clusters, and expose new insights into the processes of star formation and evolution—all phenomena we’ve simulated. Now we can train on the synthetic data to ensure we are ready for real observations.”

After the launch of Roman, astronomers will continue to utilize these simulations for a comparative analysis—their goal being to identify discrepancies between real and synthetic observations. Such differences may shed light on the physics governing the universe, potentially indicating new phenomena beyond current cosmological models.

“If we observe something that deviates from the standard cosmological model, it will be crucial to verify whether we’re witnessing new physics or if there’s an oversight in understanding the data,” said Katrin Heitmann, a cosmologist at Argonne’s High Energy Physics division involved in managing the project’s supercomputer resources. “Simulations are invaluable for this purpose.”

The OpenUniverse initiative, along with other simulation efforts by Roman’s Science Operations and Science Support teams, is geared toward equipping astronomers in anticipation of the vast datasets expected from the Roman Telescope. The collaborative project engages numerous experts from NASA’s JPL, DOE’s Argonne, IPAC, and various U.S. universities, coordinating closely with the Roman Project Infrastructure Teams, SLAC, and the Rubin LSST DESC (Legacy Survey of Space and Time Dark Energy Science Collaboration). The Theta supercomputer was operated by the Argonne Leadership Computing Facility, a user facility under the DOE Office of Science.

The Nancy Grace Roman Space Telescope is managed by NASA’s Goddard Space Flight Center in Greenbelt, Maryland, with collaboration from NASA’s Jet Propulsion Laboratory, Caltech/IPAC, and other research institutions. Its primary industry partners include BAE Systems, Inc., L3Harris Technologies, and Teledyne Scientific & Imaging.

Download high-resolution video and images from NASA’s Scientific Visualization Studio

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www.nasa.gov