A Search for Sub-millisecond Pulsations in Unidentified FIRST and NVSS Radio Sources

We have searched 92 unidentified sources from the FIRST and NVSS radio catalogs for pulsations at 610 MHz. The selected sources are bright, have no identifications, are unresolved and have significant linear polarization. Our search was sensitive to sub-millisecond pulsations from pulsars with a large range of dispersion measures. We have detected no radio pulsations from these sources and conclude that they are unlikely to be a population of previously undetected pulsars.