Total intensity variability light curves offer a unique insight into the ongoing debate about the launching mechanism of jets. For this work, we utilised the availability of radio and gamma-ray light curves over a few decades of the radio source 3C 84 (NGC 1275). We calculated the multi-band time-lags between the flares identified in the light curves via discrete cross- correlation and Gaussian process regression. We find that the jet particle and magnetic field energy densities are in equipartition (kr=1.08+/-0.18). The jet apex is located z_91.5GHz_=22-645Rs (2-20x10^-3^pc) upstream of the 3mm radio core; at that position, the magnetic field amplitude is B91.5GHz core =3-10G. Our results are in good agreement with earlier studies that utilised very-long-baseline interferometry. Furthermore, we investigated the temporal relation between the ejection of radio and gamma-ray flares. Our results are in favour of the gamma-ray emission being associated with the radio emission. We are able to tentatively connect the ejection of features identified at 43 and 86GHz to prominent gamma-ray flares. Finally, we computed the multiplicity parameter {lambda} and the Michel magnetisation {sigma}M, and find that they are consistent with a jet launched by the Blandford & Znajek (2007MNRAS.377L..49K) mechanism.
Cone search capability for table J/A+A/669/A32/alma (ALMA 91.5 GHz)