May 7, 2014
Radio Wave Emission From A Pulsar
[ Read the Article: Astronomers Make Ultra-Precise Measurement Of Pulsar Using Galaxy-Sized Lens ]
Neutron stars are particularly interesting objects to study, as some of them — called pulsars — give off pulsed radio waves whose beams sweep across telescopes at regular intervals.
“Compared to other objects in space, neutron stars are tiny — only tens of [kilometers] in diameter — so we need extremely high resolution to observe them and understand their physics. More than 45 years since astronomers discovered pulsars, we still don’t understand the mechanism by which they emit radio wave pulses.” says Dr. Jean-Pierre Macquart from the Curtin University node of the International Center for Radio Astronomy Research (ICRAR) in Perth and member of the ARC Center of Excellence for All-sky Astrophysics (CAASTRO).
But researchers were now able to use the distortions of these pulse signals as they pass through the turbulent interstellar medium (the ’empty’ space between stars and galaxies that is made up of sparsely spread charged particles) as a giant lens to reconstruct a close in view of the pulsar from thousands of individual sub-images of the pulsar.
The previous record using combined views from many telescopes was an angular resolution of 50 microarcseconds — but the team, led by Professor Ue-Li Pen (Canadian Institute of Theoretical Astrophysics), has now proven that their ‘interstellar lens’ can get down to 50 picoarcseconds, or a million times more detail.