The first Fermi Large Area Telescope (LAT) catalogue of sources (1FHL)
emitting at high energies (above 10 GeV) reports the details of 514 objects
detected in the first three years of the Fermi mission. Of these, 71 were
reported as unidentified in the 1FHL catalogue, although six are likely to be
associated with a supernova remnant (SNR), a Pulsar Wind Nebula (PWN) or a
combination of both, thereby leaving a list of 65 still unassociated objects.
Herein, we report a preliminary analysis on this sample of objects
concentrating on nine 1FHL sources, which were found to have a clear optical
extragalactic classification. They are all blazar, eight BL Lac and one flat
spectrum radio quasar, typically at redshift greater than 0.1.Comment: Proceedings of "Swift: 10 Years of Discovery", December 2-5 2014,
Rome, Italy, in Proceedings of Science (SWIFT 10