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Zhang et al. have reported the first wideband monitoring
observations of PSR J1803−3002A, a relatively bright millisecond
pulsar in the globular cluster NGC 6522 with a spin period of 7.1
ms. The observations were performed using the Parkes 64-m radio
telescope with the Ultra-Wideband Low (UWL) receiver system, which
covers 704 to 4032 MHz. Zhang et al. confirm that PSR J1803−3002A is
an isolated millisecond pulsar located near the cluster center and
probe the emission properties of the pulsar over the wide observed
band. The mean pulse profile consists of three components. Unusually,
the fractional linear and circular polarization increase with
increasing frequency. PSR J1803−3002A is a distant pulsar in the
Galactic plane, but the observations show no evidence of pulse
broadening due to interstellar scattering. The image above shows the
timing residuals for PSR J1803−3002A based on the Parkes UWL
monitoring observations over the 704 to 4032 MHz UWL band. The dashed
line marks the zero-line and corresponds to the arrival times
predicted by the timing solution. The different colours for the
residuals represent the three RF bands: Band 1 (704–1344 MHz; purple),
Band 2 (1344–2368 MHz; green) and Band 3 (2368–4032 MHz; blue). These
results demonstrate the power of ultra-wideband receivers and signal
processing systems.
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