On the Nature of Off-pulse Emission from Pulsars

In our earlier studies, we reported the detection of off-pulse emission from two long-period pulsars B0525+21 and B2045-16. The pulsars were observed at a single epoch using the 325 MHz frequency band of the Giant Meterwave Radio Telescope (GMRT). In this paper, we report a detailed study of the off-pulse emission from these two pulsars using multiple observations at two different frequencies, 325 MHz and 610 MHz bands of GMRT. We report detection of off-pulse emission during each observation and based on the scintillation effects and spectral index of off-pulse emission we conclude a magnetospheric origin. The magnetospheric origin of off-pulse emission gives rise to various interesting possibilities about its emission mechanism and raises questions about the structure of the magnetosphere.