Speaker
Description
The acceleration of relativistic jets launched by active galactic nuclei (AGN) is expected to be driven by magnetic fields. However, the exact acceleration mechanism is still uncertain, with several magnetic jet acceleration models having been proposed. In order to potentially constrain such models, measuring the magnetic field strength near the base of AGN jets is essential. With multifrequency very long baseline interferometry (VLBI) observations, the strength of the magnetic field at a distance of 1 parsec from the jet central engine can be estimated, by measuring shifts in the observation frequency dependent position of the optically thick VLBI core. We measure core-shifts and estimate magnetic field strengths for 25 AGN jets, which have been observed using the Very Long Baseline Array as part of the two-year MOJAVE multifrequency survey at 15, 24 and 43 GHz.