Anomalous Pulsar Scattering at LOFAR Frequencies

The Low Frequency Array (LOFAR) is ideally suited to pulsar scattering studies, providing broad bands at low frequencies where the imprints of the ionized Interstellar Medium (IISM) are exaggerated. We analyse a set of sources at 110-190 MHz, and find unexpectedly shallow dependencies of pulse scatter broadening on frequency. These anomalous scattering values are discussed by considering evidence for anisotropic scattering and small scattering clouds.