The central engines of radio-quiet quasars

摘要: Two rival hypotheses have been proposed for the origin of compact radio flux observed in radio-quiet quasars (RQQs). It has suggested that emission these objects, typically some two or three orders magnitude less powerful than radio-loud (RLQs), represents either from a circumnuclear starburst is produced by jets with bulk kinetic powers 10^3 times lower those RLQs similar luminosity ratios other wavebands. We describe results high resolution (parsec-scale) radio-imaging observations sample 12 RQQs using Very Long Baseline Array (VLBA). find strong evidence jet-producing central engines 8 members our sample.