Parkes observations for project P917 semester 2016APRS

PSR J0738-4042 shows a strong correlation between long-term (~years) pulse profile shape variations and changes in the spin-down rate. Such connections between pulsar emission and rotation are being discovered in more and more pulsars. Although the physical process(es) responsible for this relationship are still unclear, it is widely accepted that discrete changes in magnetosphere activity and/or structure is a possible mechanism. By analyzing data from the public Parkes archive, we find that PSR J0738-4042 also exhibits pulse-shape variations at multiple frequencies whose variation time-scale is a few minutes which may result from mode changing or pulse jitter. Variation features shorter than 30s (i.e. 80 pulses of PSR J0738-4042) cannot be resolved because of the time-resolution limitation of the public archive data. Short-term and long-term emission variability may be caused by changes with different time-scales in the pulsar magnetosphere. We propose a single-pulse polarization observations of PSR J0738-4042 to study the short time-scale emission behavior and its relationship (if any) to the longer-term variations.