Two-epoch space VLBI observations of the gamma-ray loud quasar PKS 1741-038

We present the results of high-resolution imaging of the gamma-ray loud qua sar PKS 1741-038 with the HALCA satellite and ground radio telescopes. Obse rvations were made at two epochs at an interval of nine months with the fir st-epoch observation at 1.6 and 5 GHz and with the second-epoch observation at 5 GHz. The source shows a very compact structure, but is clearly resolv ed in the space-ground baseline visibility data. The core component of the source has a brightness temperature, T-b, greater than 10(12) K in the sour ce's rest frame at each frequency. We applied three individual jet models i n order to derive the Doppler factor, delta. The core component has delta s imilar to 14, considering the T-b limit due to the inverse Compton catastro phe, while a 2.5-times larger delta is obtained assuming that the particles and magnetic field are in equipartition. Two-epoch images at 5 GHz show al most no change of the structure. Assuming that the component motion in this interval is less than our resolution, we derived the upper limit of the vi ewing angle as being 4.degrees 8. The smaller viewing angle and higher Dopp ler factor favor the inverse Compton gamma-ray emission model; we conclude that the gamma-ray emission from this source is highly Doppler-boosted.