The sub-arcsecond ILT view of the Boötes Deep Field: A link between low-frequency kiloparsec radio morphology and AGN driven ionised outflows

Active Galactic Nuclei (AGN) outflows can regulate host galaxy evolution via AGN feedback. Ionised gas outflows have been linked to enhanced radio emission. In the first paper of this series, AGN detected with the International LOFAR Telescope (ILT) at 6″ were more likely to host an [O iii] λ5007 Å outflow than AGN not detected, although only high-powered jets were ruled out as the origin of radio emission. New wide-field, sub-arcsecond resolution imaging at 144 MHz with the ILT now enables a resolved morphological study of this sample. We present the first wide-field, sub-arcsecond images of the Boötes Deep Field at 144 MHz, detecting 4074 sources in the ∼0.3″ image with a central sensitivity of 33.8 μJy beam⁻¹. For 47 AGN matched in AGN luminosity, we probe radio emission on kiloparsec-scales to investigate correlations with [O iii] outflows. This sample spans z < 0.83, 1040 < L_[OIII] < 1043 erg s⁻¹, and 10²¹ < L144MHz < 10^24.5 W Hz⁻¹. We find that if we detect an AGN on both large-scales (6″) and small-scales (0.3″), 90±7percnt have an [O iii] outflow, compared to 63±9percnt of sources detected on large-scales, but undetected on small-scales. Furthermore, 17±6percnt of sources without an [O iii] outflow are detected on kiloparsec-scales, compared to 51±12percnt of sources with an [O iii] outflow. This implies a connection between [O iii] outflows and kiloparsec-scale radio emission, which is likely AGN-driven. In contrast, AGN without an [O iii] outflow are dominated by diffuse radio emission, likely to be associated with star formation.