Abstract Details
| Name: Avishek Basu Affiliation: The University of Manchester - Jodrell Bank Centre for Astrophysics Conference ID: ASI2024_840 Title : Discovery of long-term pulse profile evolution in 7 young pulsars using MeerKAT. Authors and Co-Authors : Avishek Basu, Patrick Weltevrede, Mike J. Keith, Simon Johnston, Aris Karastergiou, Lucy S. Oswald, Bettina Posselt, Xiaoxi Song and Andrew D. Cameron Abstract Type : Oral Abstract Category : High Energy Phenomena, Fundamental Physics and Astronomy Abstract : The average pulse profile of a pulse serves as its fingerprint and is unique to every pulsar. A wealth of information about the pulsar magnetosphere is derived from its profile shape. For the majority of the pulsars, the average shape remains invariant over time. However, for very few sources variations in the profile shape have been observed. Sometimes these changes are correlated with the changes in the rotation of the pulsar, which gives insight into the dynamic nature of the magnetosphere. The MeerKAT monitoring data accrued over the last few years on ~500 pulsars under the MeerTIME's Thousand Pulsar Array (TPA) programme, has enabled the detection of subtle emission changes in seven sources not yet known to exhibit long-term profile evolution. These variations are theorised to originate from the magnetospheric state changes with associated current density variations. Precession could play a role, and emission heights could be affected. In this talk, I will briefly describe the techniques adopted to measure the subtle changes in the emission state of the pulsar both in the total intensity and polarization domain and discuss how they are connected to the rotational evolution of the neutron stars. Further, I will elucidate how these measurements have been used to derive the limits on the various measurable parameters such as changes in the emission height, impact parameter of the line of sight, and changes in the magnetospheric charge density. |