The Quasar Feedback Survey: Revealing the importance of sensitive radio imaging for AGN identification deeper into the radio-quiet regime

We present new sub-arcsecond (∼0.3–1 arcsec; ∼1–3 kpc) Very Large Array imaging at 1.4 and 6 GHz of 29 opticallyselected [O iii] luminous (L[OIII] > 1042.1 erg s−1) z < 0.2 quasars drawn from the expanded Quasar Feedback Survey(QFeedS; with L1.4 GHz = 1022.6–1026.3 WHz−1). These 29 new objects occupy the low end of the radio-power distribution(L1.4 GHz=1022.63–1023.45 WHz−1) in the QFeedS sample and are nominally ‘radio quiet’. Despite this, we find widespreadevidence of active galactic nucleus (AGN)-driven synchrotron activity. Nearly ∼ 31 per cent exhibit resolved radio structures on ∼0.1–20 kpc scales consistent with compact jets or wind-driven outflows, and ∼ 90 per cent display steep spectra(α  −1) indicative of optically thin synchrotron emission. Combining morphology, spectral index, and brightness temperature diagnostics, at least ∼ 38 per cent of the sample show clear AGN signatures that cannot be explained by starformation alone. These constitute the first results from the expanded QFeedS (now 71 quasars spanning ≈ 4 dex in radiopower) and demonstrate that compact low-power jets and AGN shocks are common deep inside the radio-quiet regime.A thorough understanding of feedback processes from quasars, deep into the ‘radio-quiet’ regime, will be obtained byconnecting these high-resolution radio observations with multiwavelength observations.