Possible Radius to Intensity Mapping in Radio Pulsar Magnetospheres
We used the Arecibo Telescope to observe and investigate various pulsars in the radio band, specifically L-band from 1130 to 1730 MHz. Our objectives were to develop an accurate description of the physical properties of their radio emission and to model the geometry of the cone of emission. As well as, to identify and explain, if present, the phenomena of: retardation, aberration and magnetic field line sweepback. Hence, to fulfill our objectives we used the method of Radius to Intensity Mapping (RIM) and determined the emission heights and the corresponding range of altitudes for different frequencies and intensities at the emission cone. In addition, we studied the effects that retardation, aberration and magnetic field line sweepback had on these signals. Our preliminary results show that for most pulsars we observed on a specific frequency: strong pulses are emitted from lower altitudes in the cone of emission; while weak pulses are emitted from higher altitudes. For most pulsars we studied: weak pulses appear to have a larger width when compared to strong pulses; consistent with a cone of emission that is narrow at the surface of the star and wide at larger radii. Finally, a shift in the emission phase was found for pulsar PSR B0523+11 which can be attributed to the effects of: retardation, aberration or magnetic field line sweepback.