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Using the Five-hundred-meter Aperture Spherical radio Telescope (FAST), astronomers have investigated the emission properties of three long-period pulsars. Results of the observational campaign are presented in a research paper Feb. 6 on the arXiv preprint server.

Pulsars are highly magnetized, rotating neutron stars emitting a beam of electromagnetic radiation. They are usually detected in the form of short bursts of stable radio emission; however, some of them are also observed via optical, X-ray and gamma-ray telescopes.

Observations show that pulsars may exhibit intriguing variability manifested as phenomena such as nulls (phases of diminished or entirely absent emission), mode changing, bright pulses and microstructures. FAST is one of the powerful tools capable of exploring these pulsar phenomena.

That is why a team of astronomers led by Habtamu Menberu Tedila of the Arba Minch University in Ethiopia has employed FAST to explore emission behaviors of three long-period pulsars, namely: PSR J1945+1211, PSR J2323+1214, and PSR J1900−0134. The study was conducted as part of the Commensal Radio Astronomy FAST Survey (CRAFTS).

"Single-pulse observations of our long-period pulsars were conducted during the pilot scans of the CRAFTS Survey using the FAST telescope. These observations utilized the 19-beam receiver and spanned a frequency range from 1.05 to 1.45 GHz," the researchers explained.

The observations detected quasi-periodic null phenomena in all the three pulsars, with durations ranging from 57 to 71.44 seconds. The null fractions for PSR J1945+1211, PSR J2323+1214, and PSR J1900−0134 were found to be 52.46, 48.48, and 27.51%, respectively.

The study identified complex emission features in PSR J1900−0134, with microstructure pulses down to 2.05 milliseconds. The other two pulsars were found to showcase asymmetric emissions, with bright pulses predominantly in their leading components.

Furthermore, the observations found quasi-periodic microstructures and various microstructure pulses in PSR J1900−0134. This suggests a periodic emission process in the pulsar magnetosphere and diverse emission characteristics.

It was also found that in all three investigated pulsars, bright pulses occur at different rates and variation in intensity among pulse profiles is present, with burst state profiles having higher peak intensities and wider widths.

Summing up the results, the authors of the paper emphasized the importance of their findings in the context of advancing our knowledge of pulsar emission mechanisms.

"Our findings offer a more nuanced understanding of pulsar emission mechanisms, showing that different emission phenomena may be interconnected and influenced by both intrinsic and extrinsic factors," the researchers concluded.

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