Low-frequency polarimetry of the millisecond pulsar PSR 1937+214.

Polarimetric observations of the msec pulsar PSR1937+214 obtained using the 250-kHz Butterworth filters centered on 431 MHz and a Nyquist sampling interval of 4 microsec with the 305-m telescope at Arecibo Observatory on April 3, 1983, are reported. The polarization waveform is plotted as the synchronous average of 820,000 pulses smoothed to a time resolution of 16 microsec, corresponding to 3.6 deg of longitude. While main-pulse polarization is found to decrease with increasing frequency as in other pulsars, the interpulse polarization increases. Analysis of the position angles supports the hypothesis that the main pulse and interpulse originate at opposite magnetic poles.