Properties of pulsar subpulse drifting in different profile components

We investigate the emission properties of the pulsars that exhibit different drifting subpulses in different pulse profile components based on the model for obliquely rotating pulsar magnetospheres of multiple emission states. Emission from subpulses is assumed coming from m discrete areas located on carousels around the magnetic axis and flowing at rates determined by the E x B drift. An emission state is defined by this drift, and a change in the emission state corresponds to a change in the drift velocity. The model is applied to eight pulsars, all displaying drifting subpulses of particular properties along two different drift-bands at different parts of the pulse profile at 21 cm observing wavelength. Simulation is performed to identify the emission states for the different drifting subpulses and the associated values of m in the emission region. The results show that drifting subpulses in different profile components correspond to particular emission states and m, and that different emission states and m can coexist in an emission region. We determine the circulation time for plasma around the magnetosphere and show that it is related to the obliquity angle. By comparing with three other pulsars that display drifting subpulses of a single drift-band, we find that drifting subpulses demonstrate similar properties when considering the different drift-bands separately. We speculate, based on our results, that the coexistence of different drifting subpulses within a pulse profile may require additional mechanism, and the phenomenon is more common in pulsars with small obliquity angle.