Landing page for project GP060

Janssen+(2021) have recently published images of the jets in Centaurus A observed with the EHT, which exhibit a limb-brightened jet morphology. However, previous cm-VLBI observations have indicated that this jet is ridge-brightened on parsec scales. One possible explanation is that the jet is intrinsically limb-brightened, but has not been observed so far due to the low angular resolution of previous observations. In light of this result, the question arises: Are all AGN jets intrinsically limb-brightened on parsec scales? Interestingly, the jets reported to be limb-brightened are associated with nearby AGNs and/or have large black holes. Here we propose new global VLBI observations of NGC315, NGC1052, and NGC4261 at 22 GHz. They are known to have ridge-brightened jets on parsec scales and have large jet viewing angles. Our proposed observations, utilizing the spirit of the global VLBI alliance, can transversely resolve the jets for the first time. If we observe limb-brightening in these large viewing angle jets, it implies that limb-brightening of parsec-scale AGN jets may not be caused by Doppler boosting, rather it may be caused by particle acceleration at the boundary between jets and the surrounding medium.

This data is part of the archive of VLBI data maintained by JIVE on behalf of the EVN, a network of radio telescopes located primarily in Europe and Asia, with additional antennas in South Africa. The EVN archive itself has the DOI https://doi.org/10.17616/R3Z197