In February 2024, scientists on Earth detected a powerful radio explosion from outer space. By finding out where it came from They then followed the brief flash of energy. Return to extraterrestrial origins and discovered something unexpected
Scientists led by Northwestern University and McGill University have traced a fast radio burst (FRB) to the edge of an ancient elliptical galaxy. Scientists previously thought that these fast radio bursts, which create more energy in a single flare, than our sun produces in an entire year. Formed from young galaxies orbiting new stars. However, the latest investigation has two parts. younger sister study Published on January 21 in Astrophysics Journal Letters It is encouraging astronomers to consider the possible diversity of FRB sources.
The February 2024 FRB, dubbed FRB 20240209A, isn't just a one-off. Between February and July 2024, the same source erupted 21 times.
“The prevailing theory is that FRBs come from magnetic fields created by supernovae whose cores collapse,” said Tarraneh Eftekhari of Northwestern University, who participated in both studies. said at a university statement– Magnetars are neutron stars that have very powerful magnetic fields. And neutron stars are very small, dense celestial objects that are believed to have formed after the explosive death of some large stars. which is a supernova
“It doesn't seem like that,” Eftekari continued. As young, massive stars end their lives in supernovae, their cores collapse. We haven't seen any evidence. of young stars in this galaxy Thanks to this new discovery This gives an image showing that not all FRBs come from young stars. There may be a subpopulation of FRBs associated with the old system.”
Using computer simulations, the old galaxy in question is 11.3 billion years old and 2 billion light years from us. Eftekari and her colleagues discovered that the galaxy is extremely bright and 100 billion times more massive than our sun.
“It appears to be the largest FRB host galaxy to date,” Eftekari said. “It is one of the most massive galaxies in existence.” Unusual FRBs do not just originate in old galaxies. But it also comes from the edge of that galaxy, specifically 130,000 light years from its center.
“Among the FRB populations, this FRB is the furthest from the host galaxy's center,” said McGill's Vishwangi Shah, a participant in both studies. “This is both surprising and exciting, as FRBs are expected to originate within galaxies. They are often located in star-forming regions. The location of this FRB so far outside its galaxy raises the question of how such an energetic event could occur in a region where no new stars are forming.”
But FRB 20240209A is not the first FRB to be detected far from an active star-forming region. But it's the second one. In 2022, astronomers tracked M81 FRB, 12 million light-years from Earth, to a cluster of stars on the edge of galaxy Messier 81.
FRB 20240209A “may be the twin of M81 (M81 FRB). It is far from its home galaxy. It is far from where any stars form, and the number of stars in its home galaxy is very ancient. It was a heyday. and now entering retirement age,” said Wenfai Fong from Northwestern University. who participated in both studies said, “At the same time This old environment made us rethink our standard FRB origin model. and turned to more exotic formation channels. which is very exciting.”
One study suggests that the new FRBs may originate from clusters of stars known as globular clusters, like the M81 FRB.
“The globular cluster origin for this repeating FRB is the most likely scenario to explain why this FRB is located outside the host galaxy,” Shah explained. is at the location of an FRB and has submitted a proposal to use the James Webb Space Telescope to follow up with a survey of the FRB's location. If yes, this would make this only the second FRB known to be in a globular cluster. If not then We will have to consider alternative exotic scenarios for the origins of FRBs.”
In other words: back to the drawing board!