1cm and 7mm VLBI images of sixteen AGN

The observations were performed with the High Sensitivity Array (HSA), including the Eelsberg telescope and the phased Very Large Array (VLA). The addition of elements with a large collecting area has allowed us to characterize the sub-parsec properties of these faint jets and to estimate their core brightness temperature and orientation. The number of sources imaged on scales <~10^3^RS has more than doubled thanks to the present study.

All targets were detected at both frequencies, with several of them presenting two-sided jet structures. Several LEG jets show hints of limb brightening. The core brightness temperatures are generally below the equipartition value, indicating that equipartition has not yet been reached and/or that the emission is de-boosted.

Among the LEGs in the sample, we identified 3C 31, 3C 66B, and 3C 465 as the most promising, as they combine a relatively high flux density (>50mJy) with a superb spatial resolution (<500RS) at 7mm. The powerful HEG 3C 452 is interesting as well, due to its highly symmetric, two-sided jet base. Most sources are expected to become prime targets for future experiments with the next generation Event Horizon Telescope (ngEHT) and next generation Very Large Array (ngVLA).