Bell, M. E., Murphy, Tara, Johnston, S., Kaplan, D. L., Croft, S., Hancock, P., Callingham, J. R., Zic, A., Dobie, D., Swiggum, J. K., Rowlinson, A., Hurley-Walker, N., Offringa, A. R., Bernardi, G., Bowman, J. D., Briggs, F., Cappallo, R. J., Deshpande, A. A., Gaensler, B. M., Greenhill, L. J., Hazelton, B. J., Johnston-Hollitt, M., Lonsdale, C. J., McWhirter, S. R., Mitchell, D. A. et al. 2016. "Time-domain and spectral properties of pulsars at 154 MHz." Monthly Notices of the Royal Astronomical Society, 461 908–921. https://doi.org/10.1093/mnras/stw1293.
We present 154 MHz Murchison Widefield Array imaging observations and variability information for a sample of pulsars. Over the declination range -80° < d < 10°, we detect 17 known pulsars with mean flux density greater than 0.3 Jy. We explore the variability properties of this sample on time-scales of minutes to years. For three of these pulsars, PSR J0953 0755, PSR J0437-4715, and PSR J0630-2834, we observe interstellar scintillation and variability on time-scales of greater than 2 min. One further pulsar, PSR J0034-0721, showed significant variability, the physical origins of which are difficult to determine. The dynamic spectra for PSR J0953 0755 and PSR J0437-4715 show discrete time and frequency structure consistent with diffractive interstellar scintillation and we present the scintillation bandwidth and time-scales from these observations. The remaining pulsars within our sample were statistically non-variable. We also explore the spectral properties of this sample and find spectral curvature in pulsars PSR J0835-4510, PSR J1752-2806, and PSR J0437-4715.
