Search for new flat-spectrum radio sources

GHz continuum observations with the Metsahovi Radio telescope are used to identifying new flat spectrum radio sources selected from lower frequency survey data. The sample is complete to sources with a flux higher than 0.5 Jy at 1.4 GHz, 0:5 between 1.4 and 4.85 GHz, declination from 0 to +75 degrees and sources more than 20 from the galactic plane. Additional strong sources from the 5 GHz survey were observed to get the sample as complete as possible down to 1.0 Jy at 22 GHz for extrapolation of source counts to lower flux levels. The new flat spectrum sources will be added to our monitoring sample and their duty cycle will be studied for the coming -ray observatiories AGILE and GLAST.