Multifrequency VLBI Observations of the Broad Absorption Line Quasar J1020+4320: Recently Restarted Jet Activity?

摘要: This paper reports very-long-baseline interferometry observations of the radio-loud broad absorption line (BAL) quasar J1020+4320 at 1.7, 2.3, 6.7, and 8.4 GHz using Japanese VLBI network (JVN) European (EVN). The radio morphology is compact with a size ~10 pc. convex spectrum stable over last decade; an observed peak frequency 3.2 equivalent to 9.5 in rest frame, suggesting age order ~100 years as source, according correlation between linear steep (CSS) giga-hertz peaked (GPS) sources. A low-frequency excess suggests relic past jet activity. may be one quasars recurrent short-lived activity during BAL-outflowing phase.