As New Year’s celebrations wind down, fireworks are likely to disappear from your neighborhood. But for neutron stars, dead stars that spin so fast that they can celebrate Earth’s New Year twice per second, the cosmic fireworks may not end appropriately.
A new study suggests that celestial fireworks produced in the high magnetic field environment near some neutron stars may explain the fast, mysterious bursts of energy called fast radio bursts (FRBs).
This link has been drawn many times before, but the results were published Wednesday (January 1) in the journal . nature, FRBs are novel in that they appear to originate very close to these extreme dead stars. The distance is just twice the distance between New York and Los Angeles.
“In these neutron star environments, magnetic fields actually reach the limits of what the universe can produce,” said team leader Kenzie Nimmo, a researcher at the Massachusetts Institute of Technology (MIT) and a postdoctoral fellow at the Kavli Institute for Astrophysics and Space Studies. said in a statement.
Fast radio bursts and neutron stars
As impressive as the light show produced by man-made fireworks on earth can be, the Federal Reserve puts it to shame.
Lasting only for a millisecond, an FRB can radiate the same energy it takes the Sun to radiate in 3 days. As a result, these powerful bursts of energy can make the entire galaxy shine brighter.
This incredible power might lead you to conclude that FRBs are rare, but that’s not the case. Since astronomers discovered the first FRB in 2007, thousands have been discovered. Some erupt up to 8 billion light-years away, while others are so close that they occur within the Milky Way.
Although bright and common, the cause of FRBs remains a mystery. But their power connects them to the most extreme environments in the universe: the regions around neutron stars.
“There has been a lot of debate about whether this bright radio emission can escape extreme plasmas,” Nimmo said.
Neutron stars are stellar remnants that form when a massive star dies, crushing a core about 1 to 2 times the mass of the Sun to a width of about 20 kilometers (12 miles). Neutron stars with strong magnetic fields are known as “magnets.”
“Atoms cannot exist around these highly magnetic neutron stars, also known as magnetars. They are simply broken apart by the magnetic field,” Kiyoshi Masui, a member of the research team and an MIT researcher, said in a statement.
There are two general theories surrounding magnetar and FRB emissions. One suggests that they occur near dead stars in turbulent conditions created by the object’s extreme gravity. Other theories suggest that FRBs are created by shock waves propagating from neutron stars, propelling them further away from the dense stellar remnant.
To choose among these sources, the team chose one FRB called FRB 20221022A, a radio signal with several unique properties. And scientists were sure to use surprising new analytical methods.
Twinkle, Twinkle FRB
FRB 20221022A was first discovered in 2022 by the Canadian Hydrogen Intensity Mapping Experiment (CHIME) radio telescope. It was confirmed that this occurred in a neutron star in a galaxy about 200 million light years away.
In many ways, FRB 20221022A is a typical FRB, but one thing that stood out about the CHIME data was the fact that the light in this signal was polarized. This indicates that it occurred near a neutron star.
To see if this was true, the team used the “flashes” of this FRB to analyze in depth and obtain a more precise location for the origin. If the term flash sounds familiar, it’s because it’s the physical process that causes a star to “twinkle” when the light it emits hits particles in Earth’s atmosphere.
The team reasoned that the flashes of this FRB could help determine the size of the region from which it emerged.
More flashes mean they come from the turbulent magnetic environment around the neutron star. The lack of an observed flash means it is further away from the neutron star, which favors the shock wave theory.
Changes in FRB brightness indicate that FRB 20221022A exploded within 10,000 km (6,200 miles) of a rapidly rotating neutron star. For context, it’s only about 1/40th the distance between the Earth and the Moon.
“Enlarging a 10,000 km area from 200 million light-years away is equivalent to being able to measure the width of a DNA helix about 2 nanometers wide on the surface of the moon,” Masui said. “There’s an incredible variety of scales involved.”
The team’s in-depth investigation of FRB 20221022A appears to rule out the possibility that FRB emerges from shock waves hitting the magnetar’s wider environment.
“What’s interesting here is that the energy stored in the magnetic field close to the source can be twisted and reorganized and released as radio waves that we can see on the other side of the universe,” Masui explained.
The team’s discovery marks the first evidence that FRBs originate near neutron stars, and the team hopes their scintillation technique can now be applied to other FRBs.
“These explosions happen all the time, and CHIME detects them multiple times a day. There can be a lot of diversity in how and where they occur, and this flash technology will be very useful in isolating the different physics that drive them,” Masui said. said: This explosion.”
