Speaker
Description
Pulsars generally exhibit stable integrated pulse profiles, making them
powerful tools for precision timing experiments. While short-term vari-
ability, such as mode-changing and nulling, is known in young pulsars,
studies suggest that long-term profile changes may also occur, potentially
correlated with the spin-down rate. Millisecond pulsars (MSPs), typi-
cally more stable, have shown hints of such variability in rare cases (e.g
J1022-1001). In this work, we investigate long-term profile evolution in
MSPs using five years of data from the MeerKAT Pulsar Timing Array
(MPTA), covering 83 sources leveraging the high sensitivity of MeerKAT.
We employ a two-dimensional Gaussian Process regression model with a
separable time-phase kernel, following Keith et al. (2025), to detect subtle
variations in pulse shape. Preliminary results reveal measurable long-term
changes in a subset of MSPs. This study explores whether these types of
variations are prevalent in MSPs and if they show correlation with the
spin-down rate as normal pulsars.
