Radio and gamma-ray properties of extragalactic jets from the TANAMI sample

The TANAMI program has been observing parsec-scale radio jets of southern (declination south of -30 ) -ray bright AGN, simultaneously with Fermi/LAT monitoring of their -ray emission, via high-resolution radio imaging with Very Long Baseline Interferometry techniques. We present the radio and -ray properties of the TANAMI sources based on one year of contemporaneous TANAMI and Fermi/LAT data. A large fraction (72%) of the TANAMI sample can be associated with bright -ray sources for this time range. Association rates differ for different optical classes with all BL Lacs, 76% of quasars, and just 17% of galaxies detected by the LAT. Upper limits were established on the -ray flux from TANAMI sources not detected by LAT. This analysis led to the identification of three new Fermi sources whose detection was later confirmed. The -ray and radio luminosities are related by L L 0.89 0.04 r . The brightness temperatures of the radio cores increase with the average -ray luminosity and the presence of brightness temperatures above the inverse Compton limit implies strong Doppler boosting in those sources. The undetected sources have lower /radio luminosity ratios and lower contemporaneous brightness temperatures. Unless the Fermi/LAT-undetected blazars are much -ray-fainter than the Fermi/LAT-detected sources, their -ray luminosity should not be significantly lower than the upper limits calculated here.