Einstein Probe Detects Mysterious Blast of X-Rays From the Early Universe

On March 15, 2024, a space-based observatory detected a burst of low-energy X-rays from deep in the ancient universe, fluctuating in brightness for more than 17 minutes before fading. About an hour later, ground-based telescopes picked up visible light from the same source, when the universe was about a billion years old.

D The newly launched Einstein Probe Already noticing distant explosions with the potential to ignore what we know about the early years of the universe. Using its wide-field X-ray telescope, the spacecraft detected so-called soft, or low-energy, X-rays, which lasted for an unusually long time. These events are known as fast X-ray transients (FXRT) and the newly spotted burst has been designated EP240315a.

After monitoring the burst at radio wavelengths for three months, the team of astronomers behind the detection confirmed that the energy output was consistent with a gamma-ray burst when the universe was only 10 percent of its current age. So given the estimated age of the universe is 13.8 billion years, the explosion occurred when the universe was about 1.38 billion years old.

“These results show that a significant fraction of FXRT may be associated with [gamma-ray bursts] And that sensitive X-ray monitors, such as the Einstein Probe, can spot them in the distant universe,” said Roberto Ricci, a researcher at the University of Rome Tor Vergata in Italy and one of the authors behind the new paper In the details of the discovery, Dr statement. “Combining the power of X-ray and radio observations gives us a new way to explore these ancient explosions without detecting gamma rays.”

EP240315a detected soft X-rays for the first time from an ancient explosion that lasted so long. Follow-up observations using the Gemini-North Telescope in Hawaii and the Very Large Telescope in Chile measured visible light from the same location, confirming that the burst came from about 12.5 billion light-years away.

Gamma-ray bursts are brief flashes of high-energy light and are the most powerful explosions in the universe, usually triggered by the collapse of a massive star or the merger of a neutron star. These explosions are also known to emit large amounts of X-rays. Recently discovered soft X-rays trace back to GRB 240315C, a gamma-ray burst first detected by the Burst Alert Telescope (BAT) at NASA’s Neil Gehrels Swift Observatory, along with the Konus instrument on NASA’s Wind spacecraft. Additional data provided by

Although gamma-ray bursts are associated with X-rays, the newly discovered fast X-ray transient is an anomaly. X-rays typically precede gamma rays by a few tens of seconds, but EP240315a appears more than six minutes (372 seconds) before GRB 240315C. “Such a long delay has never been seen before,” said Hui Sun, a team member at the Einstein Probe Science Center at the National Astronomical Observatories of the Chinese Academy of Sciences and co-author of the new study.

The mystery of the long duration between X-rays and gamma-ray bursts, in addition to the long duration of X-rays, has led to questions about whether gamma-ray bursts actually explode as scientists believe.

The Einstein Probe, an X-ray telescope operated by the Chinese Academy of Sciences, and built in collaboration with the European Space Agency and the Max Planck Institute for Extraterrestrial Physics, was launched on January 9, 2024. Its wide-field X-ray telescope beams X-ray light into square tubes in a grid, which means it can observe 3,600 square degrees (just under a tenth of the celestial sphere) in a single shot.

“As the Einstein Probe opened its eyes to our sky, it found fascinating new phenomena,” Eric Kulkers, ESA’s Einstein Probe project scientist, said in a statement. “That’s pretty good and should mean many more interesting discoveries to come.”