A precessing and nutating jet in OJ287

: Silke Britzen, C. Fendt, G. Witzel, S.-J. Qian, I. N. Pashchenko, O. Kurtanidze, M. Zajacek, G. Martinez, V. Karas, M. Aller, H. Aller, A. Eckart, K. Nilsson, P. Arévalo, J. Cuadra, M. Subroweit, A. Witzel

Publisher: Cambridge University Press

: 2020

: Proceedings of the International Astronomical Union

: 14

: 250

: 251

DOI: https://doi.org/10.1017/S1743921318008049

We re-analyzed OJ287 in 120 Very Long Baseline Array (VLBA, MOJAVE)
observations (at 15 GHz) covering the time span between Apr. 1995 and
Apr. 2017. We find that the radio jet motion over the sky is consistent
with a precessing and nutating jet source. The variability of the radio
flux-density can be explained by Doppler beaming due to a change in the
viewing angle. We suggest that part of the optical emission is due to
synchrotron emission related to the jet radiation. We find a strikingly
similar scaling for the timescales for precession and nutation as
indicated for SS433 with a factor of roughly 50 times longer in OJ287.