SIMBAD references

We aim to investigate the flux density modulation from pulsars and the specific behaviour of the modulation index versus frequency. Several pulsars were observed with the Effelsberg radio telescope at 8.35GHz. Their flux density time series were corrected for interstellar scintillation effects. We present measurements of modulation indices for eight pulsars. We confirm the presence of a critical frequency at ∼1GHz for these pulsars (including three new ones from this study). We derived intrinsic modulation indices for the resulting flux density time series. Our data analysis revealed strong single pulses detected from five pulsars.