Scientists Ride the 'Drifting Carousel' to Understand Radio Wave-Emitting Stars
Scientists may soon understand the mysterious mechanism that causes beams of radio waves to shoot out from pulsars - super-magnetic rotating stars in our Galaxy. New research from Curtin University, obtained using the Murchison Widefield Array (MWA) radio telescope located in the Western Australian outback, suggests the answer could lie in a 'drifting carousel' found in a special class of pulsars. Thousands of pulsars have been seen since their first discovery in the late 1960s, but questions still remain as to why these stars emit radio beams in the first place, and what type of emission model best describes the radio waves, or 'light', that can be seen. The 'drifting carousel' model describes the emission as coming from patches of charged particles, arranged in a rotating ring around magnetic field lines, or a carousel.
Transcript
00:00:00 wholesales were first discovered in the late 1960s when their beams of radio emission swept across the field of view of our telescopes and creators regular signal spikes similar to the beam of a lighthouse since then we have discovered thousands of pulsars in our own galaxy and we have learned that they are neutron stars that are very dense have strong magnetic fields and rotate with
00:00:24 exceptionally precise timing but intriguingly we still don't know what exactly causes the radio emission partly because there is a lot of variations between the pulsar signals hi my name is Sam McSweeney a PhD student with Castro at curtin university I studied Vista goes from a special class of pulsars that can help us understand this emission mechanism the classical pulsar
00:00:49 model describes the emission that is shooting out from the magnetic poles of the pulsar as a light cone if this cone was solid and unchanging the signal would look the same with every rotation but there is actually structure in the pulse signals which indicates that the beam Domitian is not coming from a single but from several emission reasons the signal that we observe could for
00:01:13 example be produced by a kind of carousel of sub pulses rotating at its own speed in addition to the pulsar rotation this can explain the stripy pattern in the signal in this special class of pulsars we occasionally find a change of the rotation speed of their sub pulse carousel the carousel rotation appears to get faster at some times and slower at others we used the merchants
00:01:42 and why fuel array or mwa in the Western Australian outback to collect data from these pulsars operating at low radio frequencies we have been able to analyze the changes in their rotation speed in great detail an understanding of the sub pulsar's might hold the key to figuring out why pulsars give off this radio emission in the first place one omission model to test is the effect of surface
00:02:07 temperature patches of charged particles that rotate around magnetic field lines might rotate as hot spots on the pulse are surface developed to cover a large frequency range and simultaneously trace the emission at different distances from the surface of the pulses we will combine the data from three telescopes the MWA the giant meter wave radio telescope in
00:02:31 india and the CSIRO Parkes radio telescope in New South Wales