Giant radio pulses from pulses are a hundred times more energetic than previously believed

A global scientific collaboration using data from NASA’s Neutron Star Interior Composition Explorer (NICER) telescope on the International Space Station has detected X-rays at the radio bursts of the pulsar in the Nebula. The finding shows that these eruptions, called giant radio pulses, release much more energy than previously thought.

A pulsar is a type of fast-rotating neutron star, the crushed, city center of a star that exploded like a supernova. A young, isolated neutron star can rotate tens of times per second, and its winding magnetic field drives rays of radio waves, visible light, X-rays and gamma rays. As these beams sweep past the Earth, astronomers observe clock-like emission pulses and classify the object as a pulsar.

“Out of more than 2800 catalogs, the Crab Pulse is one of only a few that emit giant radio pulses, which occur sporadically and can be hundreds to thousands of times brighter than ordinary pulses,” said scientist Teruaki Enoto at the RIKEN. Pioneer Research Cluster in Wako, Saitama Prefecture, Japan. “After decades of observations, it is shown that only the Krap improves its giant radio pulses with emissions from other parts of the spectrum.”

The new study, published in the April 9 issue of Science and is now available online, analyzing the largest amount of simultaneous X-ray and radio data ever collected from a pulsar. It increases the perceived energy range associated with this improvement phenomenon thousands of times.

The crab nebula and its pulsar are about 6,500 light-years away in the constellation Taurus and are formed in a supernova whose light reached Earth in July 1054. The neutron star rotates 30 times per second, and at X-ray and radio wavelengths it is the brightest carotid arteries in the air.

Between August 2017 and August 2019, Enoto and his colleagues used NICER to repeatedly observe the Crab pulsar in X-rays with energy up to 10,000 electron volts, or thousands of times the visible light. While NICER watched, the team also studied the object using at least one of the two radio telescopes on the ground in Japan – the 34-meter dish in the Kashima Space Technology Center and the 64-meter dish in the Usuda Deep from the Japanese Aviation and Aerospace Agency. Space Center, both operating at a frequency of 2 gigahertz.

he combined a data system to effectively give the researchers almost one and a half days of simultaneous X-ray and radio coverage. After all, they captured activity in 3.7 million pulsar revolutions and delivered about 26,000 giant radio pulses.

Giant pulses break out rapidly and rise in millionths of a second and occur unpredictably. However, when it does occur, it coincides with the regular pulse of the clock.

NICER records the arrival time of each X-ray that it detects within 100 nanoseconds, but the telescope’s timing is not the only benefit for this study.

“NICER’s ability to detect bright X-ray sources is almost four times greater than the combined brightness of both the pulsar and its nebula,” said Zaven Arzoumanian, the project’s science leader, at NASA’s Goddard Space Flight Center in Greenbelt. , Maryland, said. “Thus, these observations were largely unaffected by accumulation – where a detector counts two or more x-rays as a single event – and other problems that made earlier analyzes difficult.”

The Enoto team combined all the X-ray data that coincided with giant radio pulses, revealing an X-ray gain of about 4% that occurred accordingly. This is strikingly similar to the 3% increase in visible light that is also related to the phenomenon, which was discovered in 2003. Compared to the brightness difference between the normal and giant pulses of the Krap, these changes are remarkably small and present the theoretical models a challenge to explain.

The improvements suggest that giant pulses are a manifestation of underlying processes that produce emissions that spread the electromagnetic spectrum from radio to X-rays. And because X-rays hit the radio waves millions of times, even a modest increase represents a major energy contribution. The researchers conclude that the total released energy associated with a giant pulse is tens to hundreds of times higher than previously estimated only by the radio and optical data.

“We still do not understand how or where pulsars deliver their complex and comprehensive emissions, and it is gratifying that we have added another piece to the puzzle with more wavelengths of these fascinating objects,” says Enoto.