Orateur
Description
Interstellar turbulence critically influences the propagation of pulsar radio signals, affecting both the timing precision and the interpretation of interstellar plasma properties. While its statistical behaviour in the diffuse ionised medium is relatively well described by a Kolmogorov-like spectrum, the nature of turbulence within discrete structures such as HII regions remains poorly understood. The lines of sight of more than 600 pulsars are known to intersect HII regions, six of which are included in the pulsar pool observed with the LOFAR observatory. These lines of sight offer a rare opportunity to probe turbulence in more extreme plasma environments, where enhanced density and complex internal structure may lead to deviations from canonical models. To characterise the turbulent spectrum, I analyse dispersion measure time series using statistical tools such as the structure function, which enables inference of the power spectrum of electron density fluctuations. In parallel, I examine scintillation observables to extract complementary constraints on the structure of the plasma across various scales. This multi-probe approach aims to build a coherent physical picture of the turbulent conditions in HII regions and to assess their role in contributing to propagation-induced noise in high-precision pulsar timing experiments.