Interferometric Monitoring of Gamma-ray Bright AGNs I: Results of
  Single-epoch Multifrequency Observations
  We present results of single-epoch very long baseline interferometry (VLBI)
observations of gamma-ray bright active galactic nuclei (AGNs) using the Korean
VLBI Network (KVN) at 22, 43, 86, and 129~GHz bands, which are part of a KVN
key science program, Interferometric Monitoring of Gamma-ray Bright AGNs
(iMOGABA). We selected a total of 34 radio-loud AGNs of which 30 sources are
gamma-ray bright AGNs with flux densities of
$>6\times10^{-10}$~ph~cm$^{-2}$~s$^{-1}$. Single-epoch multi-frequency VLBI
observations of the target sources were conducted during a 24-hr session on
2013 November 19 and 20. All observed sources were detected and imaged at all
frequency bands with or without a frequency phase transfer technique which
enabled the imaging of 12 faint sources at 129~GHz, except for one source. Many
of the target sources are resolved on milliarcsecond scales, yielding a
core-jet structure with the VLBI core dominating the synchrotron emission on
the milliarcsecond scale. CLEAN flux densities of the target sources are
0.43-28~Jy, 0.32-21~Jy, 0.18-11~Jy, and 0.35-8.0~Jy in the 22, 43, 86, and
129~GHz bands, respectively.
