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We have observed the composite active galactic nucleus (AGN)-starburst galaxyNGC 6764 with the Very Long Baseline Array at 1.6 and 4.9 GHz. Theseobservations have detected a "core-jet" structure and a possible weakcounterjet component at 1.6 GHz. The upper limits to the core and jet (1.6-4.9GHz) spectral index are 0.6 and 0.3, respectively. Taken together with the highbrightness temperature of ~10^7 K for the core region, the radio emissionappears to be coming from a synchrotron jet. At a position angle of 25 degrees,the parsec-scale jet seems to be pointing closely toward the western edge ofthe southern kpc-scale bubble in NGC 6764. A real connection between theparsec- and sub-kpc-scale emission would not only suggest the presence of acurved jet, but also a close link between the AGN jet and the radio bubbles inNGC 6764. We demonstrate that a precessing jet model can explain the radiomorphology from parsec- to sub-kpc scales, and the model best-fit parameters ofjet speed and orientation are fully consistent with the observedjet-to-counterjet surface brightness ratio. The jet however appears to bedisrupted on scales of hundreds of parsecs, possibly due to interaction withand entrainment of the interstellar medium gas, which subsequently leads to theformation of bubbles. The jet energetics in NGC 6764 suggest that it would take12-21 Myr to inflate the (southern) bubble. This timescale corresponds roughlyto the starburst episode that took place in NGC 6764 about 15-50 Myr ago, andcould be indicative of a close connection between jet formation and thestarburst activity in this galaxy.

Parsec-scale Imaging of the Radio-bubble Seyfert galaxy NGC 6764