Study of the first irregular eclipsing black widow pulsar J1326-4728B
Huang, Wucheng
We present a study of the first irregular eclipsing black widow pulsar J1326-4728B originally discovered by the Globular Cluster Omega Centauri Survey conducted with the Parkes Telescope. The pulsar has a rotational period of 4.79 ms and is in a tight 2.15 hours orbit around a very low mass (m_c \geq 0.015M_sun) companion. This pulsar shows very clear irregular eclipses, while similar ones have been observed only in redback systems, such as J0024-7204V by Parkes and J1717+4308A by FAST. The eclipses in J1326-4728B always show a long duration (at least 30 mins) and sometimes with a short duration. Using Parkes UWL observations in the range of 704-4032 MHz and one MeerKAT L-band observation, we have measured variations in flux density, dispersion measure and eclipse duration, in order to solve the eclipsing mechanism of this source. We conclude with a discussion of how these measurements can help us understand the mass loss rate from the companion star, which could be used to determine the upper limit on the mass-transfer rate in future pulsars shown to be transitioning from being a low-mass X-ray binary to a MSP.