2022RAA....22d5001W

We present simultaneous broad-band radio observations on the abnormal emission mode from PSR B1859+07 using the Five-hundred-meter Aperture Spherical radio Telescope (FAST). This pulsar shows peculiar emission, which takes the form of occasional shifts of emission to an early rotational phase and mode change of emission at the normal phase. We confirm all these three emission modes with our data sets, including the B (burst) and Q (quiet) modes of the non-shifted pulses and the emission shift mode with a quasi-periodicity of 155 pulses. We also identify a new type of emission shift event, which has emission at the normal phase during the event. We studied polarization properties of these emission modes in detail, and found that they all have similar polarization angle curve, indicating the emissions of all these three modes are from the same emission height.