Cosmic fireworks, invisible to our eyes, fill the night sky. We can see this elusive light show thanks to the Large Telescope (LAT) on NASA’s Fermi Space Gamma-ray Telescope, which observes the sky in gamma rays, the highest-energy form of light. This animation shows the crazy gamma-ray activity of the sky during one-year observations from February 2022 to February 2023. The flicker circles represent only a subset of the more than 1,500 light curves (records of how sources change brightness over time) collected by the LAT. during his nearly 15 years in space.

Thanks to the work of an international group of astronomers, this data is now publicly available in an interactive library that is constantly updated. The article about the warehouse was published on March 15, 2023. Astrophysical Journal Supplement Series.

“We were inspired by this database from astronomers who study galaxies and want to compare visible and gamma-ray light curves over long time scales,” said Daniel Koczewski, repository co-author and astrophysicist at NASA’s Marshall Space Flight Center in Huntsville, Alabama. . “We received requests to process one object at a time. The scientific community now has access to all analyzed data for the entire catalog.”

See cosmic gamma-ray fireworks in this animation using only one year of data from the Large Telescope (LAT) on NASA’s Fermi Space Gamma-ray Telescope. The purple circle of each object increases as it gets brighter and decreases as it darkens. The yellow circle represents the Sun following its annual path across the sky. The animation shows a subset of the LAT gamma ray recordings now available for over 1,500 objects in a new constantly updated pool. More than 90% of these sources are a type of galaxy called a blazar, powered by a supermassive black hole.

More than 90% of the sources in the dataset are blazars, the central regions of galaxies that host active supermassive black holes that create powerful jets of particles aimed almost directly at Earth. Ground-based observatories such as the National Science Foundation’s IceCube neutrino observatory in Antarctica can sometimes detect high-energy particles produced in these jets. Blazars are important sources for multi-messenger astronomy, where scientists use combinations of light, particles, and space-time vortices to study the cosmos.

“In 2018, astronomers announced for the first time the potential co-detection of gamma rays and high-energy particles called neutrinos from a blazar with the Fermi LAT and IceCube,” said co-author Michela Negro, an astrophysicist at the university. NASA Goddard Space Flight Center in Maryland, Baltimore County and Greenbelt, Maryland. “Having a historical database of light curves can lead to new insights into past events in multimessenger.”

In the animation, each frame represents three daily observations. The purple circle of each object increases as it gets brighter and decreases as it darkens. Some objects fluctuate throughout the year. The reddish-orange band running through the middle of the sky is the central plane of our Milky Way galaxy, a continuous gamma-ray generator. Lighter colors indicate a brighter glow. The yellow circle shows the apparent annual orbit of the Sun across the sky.

Processing the entire catalog took about three months, or more than 400 computer years, distributed across 1,000 nodes in a computer cluster at the SLAC National Accelerator Laboratory in Menlo Park, California. Fermi’s primary vehicle, the LAT, scans the entire sky every three hours. It detects gamma rays with energies from 20 million to 300 billion electron volts. For comparison, the energy of visible light is mostly between 2 and 3 electron volts.