Crab Nebula’s Strange Zebra Pattern Pulsars Could Be Due to Its Unusual Plasma Density

Researchers unveiled a groundbreaking explanation for the mysterious zebra-like radiation pattern observed from the Crab Pulsar, a neutron star located 6,000 light-years away in the centre of the Crab Nebula. The pulsar, which emerged from a supernova recorded in 1054, has intrigued scientists with its unique high-frequency emission, distinct from other pulsars observed to date.

Understanding the Zebra-Like Radiation

In a study published in Physical Review Letters on November 15, the pulsar’s peculiar emission was described as resembling a zebra pattern in the electromagnetic spectrum. It was explained by Mikhail Medvedev, a physicist at the University of Kansas.

In a statement released by the university, he attributed the phenomenon to the diffraction of electromagnetic waves caused by plasma in the pulsar’s magnetosphere. Medvedev explained that this emission, akin to a lighthouse beam, creates pulses of radiation that we detect as the star rotates.

The zebra pattern was initially detected in 2007, but explanations for it had remained scarce. Medvedev’s research identified the band spacing within the pulsar’s emissions, proportional to its high-frequency wavelengths between 5 and 30 gigahertz.

Plasma density surrounding the pulsar, described as superheated charged particles, was pinpointed as the cause of the diffraction. This has enabled the use of fringe measurements to map the plasma’s density distribution in the magnetosphere.

Implications for Future Research

Medvedev emphasised that the Crab Pulsar’s energetic youthfulness—around 1,000 years old—provides a unique opportunity for study. The methodology developed could expand understanding of young neutron stars and even test principles like Einstein’s general relativity in known binary pulsars.

The discovery marks a significant step forward in pulsar research, offering tools to decode the intricate behaviours of some of the universe’s most energetic objects.