NASA's Fermi gamma-ray space telescope used 14 years of data to create a stunning time-lapse movie of the entire sky, capturing the dynamic universe. The film highlights the path of the Sun, the gamma-ray glow of the Milky Way, and distant galaxies known as "quasars." The film reveals the beauty and complexity of the universe, showing high-energy events inside and outside the Milky Way, including the explosion of a supermassive black hole.

NASA's Fermi Space Telescope reveals a 14-year time-lapse movie that reveals the dynamic universe through gamma-ray imaging. The film highlights the Milky Way's gamma-ray glow, solar flares and distant galaxies powered by black holes. In the all-sky time-lapse movie produced based on data obtained over 14 years, the universe comes to life. Against the background of high energy sources inside and outside the Milky Way, our sun occasionally flashes dazzling light and quietly cuts a path across the sky.

"The Milky Way's bright and steady gamma-ray glow is punctuated by powerful bursts of near-light speed jets driven by supermassive black holes at the cores of distant galaxies that last for days," said Seth Digel, a senior scientist at SLAC National Accelerator Laboratory in Menlo Park, California. "These dramatic bursts can appear anywhere in the sky, occurring millions to billions of years ago, and their light was just reaching Fermi when we observed it."

From solar flares to black hole jets: NASA's Fermi Gamma-ray Space Telescope team creates unique time-lapse photography of the dynamic, energetic sky. Judy Racusin, associate scientist of the Fermi project, narrates the video, which compresses 14 years of gamma-ray observations into six minutes. Source: NASA Goddard Space Flight Center and NASA/DOE/LAT Partnership

Gamma rays are the most energetic light. The film shows the intensity of gamma rays with energies exceeding 200 million electron volts detected by the Fermi Large Area Telescope (LAT) between August 2008 and August 2022. For comparison, visible light has energy between 2 and 3 electron volts. Brighter colors mark the locations of stronger gamma ray sources.

In a movie, the first thing you see is a light source that steadily arcs across the screen. "This is our Sun, and its surface motion reflects the Earth's annual orbital motion around the Sun," said Fermi associate scientist Judy Racusin.

An artist's impression of the Fermi Gamma-ray Space Telescope in orbit. Source: NASA

In most cases, large-area space telescopes detect the Sun faintly, caused by accelerating particles called cosmic rays - collisions with atomic nuclei approaching the speed of light. Gamma rays are produced when they hit the Sun's gas and even the light it emits. Sometimes, though, the Sun suddenly brightens, producing powerful bursts of energy called solar flares, briefly making our star one of the brightest gamma ray sources in the sky.

The film shows the sky from two different perspectives. The rectangular view shows the entire sky centered on the center of the Milky Way. This highlights the central plane of the Milky Way, which emits gamma rays produced by cosmic rays striking interstellar gas and starlight. In addition, there are many other sources scattered throughout the Milky Way, including neutron stars and supernova remnants. Above and below this central band, what we see is the wider universe beyond the Milky Way, full of bright, rapidly changing light sources.

Most of these are actually distant galaxies, which can be better viewed from different perspectives centered on the north and south poles of the Milky Way. Each of these galaxies, known as blazars, has a black hole at its center with a mass equivalent to a million suns or more.

Somehow, these black holes produce extremely fast-moving jets of material, and we can almost look right down into one of these jets, a perspective that enhances their brightness and variability. "This tells us that something has changed in the jet," Racusin said. "We regularly observe these celestial sources and alert other telescopes in space and on the ground when something interesting is happening. We have to catch these flares quickly before they disappear, and the more observational data we can collect, the better we can understand these events."

Fermi plays a key role in an expanding network of missions that work together to capture these changes taking place in the universe.

Many of these galaxies are very distant. For example, the light from a flare called 4C+21.35 has traveled for 4.6 billion years, meaning that the flares we see today actually occurred when the sun and solar system were beginning to form. Other bright stars are more than twice as far away, and together they provide a stunning snapshot of black hole activity across cosmic time.

Many of the short-lived events Fermi studied, such as gamma-ray bursts, the most powerful explosions in the universe, are not visible in time-lapse photography. This is the result of sharpening the image by processing several days of data.

The Fermi Gamma-ray Space Telescope is an astrophysics and particle physics collaboration managed by Goddard. The Fermi telescope was developed in collaboration with the U.S. Department of Energy, with important contributions from academic institutions and partners in France, Germany, Italy, Japan, Sweden and the United States.

Compiled source: ScitechDaily