1 2009 Fermi Symposium, Washington, D.C., Nov. 2-5 arXiv:1001.1566v1 [astro-ph.CO] 10 Jan 2010 The spectral energy distribution of gamma-faint compact radio sources C. S. Chang $^{1}$, E. Ros1$_{,}$$^{2}$, M. Kadler3$_{,}$4$_{,}$$^{5}$, the Fermi LAT Collaboration, and the F-GAMMA team ∗ $^{1}$Max-Planck-Institut f¨ur Radioastronomie, Auf dem H¨ugel69, D-53121 Bonn, Germany $^{2}$Departament d’Astronomia i Astrof´ısica, Universitat de V al` encia, E-46100 Burjassot, Spain $^{3}$Dr. Remeis-Sternwarte & ECAP, Sternwartstr. 7, D-96049 Bamberg, Germany $^{4}$CRESST/NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA and $^{5}$USRA, 10211 Wincopin Circle, Suite 500 Columbia, MD 21044, USA MOJAVE is a VLBI program which monitors a statistically complete, radio-selected sample of 135 relativistically beamed, flat-spectrum active galactic nuclei for over more than a decade. In order to understand the high-energy behavior of this radio complete sample, we are performing Swift fill-in observations on the complete MOJAVE-I sample since 2007. The complete study of the spectral energy distribution from radio to X-ray bands on this radio-selected sample will provide us an opportunity to understand the nature of AGN. Here we present the preliminary results of the spectral energy distributions of six gamma-quiet or faint sources from this project: NRAO 140, PKS 0403 − 13, PKS B0422+004, PKS 0823+033, 3C 309.1, and 3C 380. and discuss the preliminary results obtained by the broadband study of the six sources. We show the preliminary results of the following sources: NRAO 140, PKS 0403 − 13, PKS B0422+004, PKS 0823+033, 3C 309.1, and 3C 380. All sources present a compact core-jet structure, and the source properties are shown in Table I. To construct the SED of the 6 sources we collected datasets obtained during Fermi ’s mission, which started on 11 June 2008. The simultaneous data we use in this paper include: the University of Michi- gan Radio Astronomy Observatory (UMRAO), VLBA from the MOJAVE program, Effelsberg 100-m tele- scope, and the IRAM Plateau de Bure Interferometer (all four in radio), Swift UVOT/XRT (optical/UV and X-ray), and Fermi LAT (gamma-ray) datasets. Effelsberg and PdB data are obtained in the frame- work of the F-GAMMA project [7]. The Swift data were analyzed by using NASA’s HEASOFT software in its version 6.6.3. The optical/UV flux densities of Swift UVOT are obtained using aperture photome- try, and the X-ray flux densities of Swift XRT data are estimated by using XSPEC version 12.5.0 to fit the spectra. Fermi LAT data were analyzed by using Fermi Science Tools version v9r10 and instrumental response functions (IRFs) version P6 V3 DIFFUSE . For the broadband SED, we included archival values from NASA extragalactic database (NED). Here we present preliminary broadband SED of the six sources from radio to gamma-ray energies (Figure 1 to 6). The LAT spectral data presented here are obtained from the first 11-month dataset. We do not include the LAT spectrum of 3C 309.1 because it is To understand the high-energy behavior of the MO- JAVE sample, we are performing Swift fill-in observa- tions since 2007 on all the objects in the sample. Our aim is to study the SED of the radio-selected AGN sample from radio to gamma-ray, search for correla- tions, and to picture the physical mechanisms behind. In this paper, we selected six radio-bright AGN which are faint or quiet in the preliminary LAT first-year catalog, and which were not detected by EGRET. Studying those sources could help us to understand the connection between radio and gamma-ray emis- sions, and the reason which makes those bright radio sources to be faint in gamma-rays. Here we present The MOJAVE (monitoring of jets in active galac- tic nuclei with VLBA experiments) program [1] has been monitoring a statistically complete, radio flux limited sample [2] of 135 radio loud active galactic nuclei (AGN) for more than a decade. This monitor- ing program provides the parsec-scale morphology of AGN jets evolving with time. After Fermi ’s launch in June 2008, we have the opportunity to investigate the relation between the parsec-scale radio-jet proper- ties and the gamma-ray emission. First results of the correlation between gamma and radio properties have been presented in [3]-[6]. The gamma-ray emission is thought to be generated close to the super mas- sive black holes hosted in AGN. Moreover, with the simultaneous multiwavelength observations of AGN, we are able to investigate the relation between parsec- scale jets and broadband spectral energy distribution (SED) of AGN. 2. Preliminary results 1. Introduction ∗ The F-GAMMA team (in alphabetical order): E. Angelakis, L. Fuhrmann, T. P. Krichbaum, S. Larsson, N. Marchili, G. Nestoras, H. Ungerechts, J. A. Zensus et al. eConf C091122