One hypothesis for the emission mechanism has light of different radio frequencies coming from different heights above the pulsar's surface.
By observing a pulsar with the Lovell Telescope in the UK, the Effelsberg Telescope in Germany, and both the high and low LOFAR bands, astronomers span eight octaves in frequency, thus different heights in the pulsar magnetosphere, as shown in the graphic (right). The pulses, or "blips," have a different shape in each frequency.
Pulsars are not only themselves interesting objects of study, but excellent probes of the gas in our galaxy along the line of sight, as well as laboratories for studying general relativity and searching for gravity waves. They may not be the beacons of "little green men," but they are some of the coolest things in astronomy, and the new insight from low frequency observatories is sure to make them even cooler.
Images: ESA (top), Aris Karastergiou, University of Oxford (bottom).