A parsec-scale wobbling jet in the high-synchrotron peaked blazar PG 1553+113
A parsec-scale wobbling jet in the high-synchrotron peaked blazar PG 1553+113
Context. The detection of quasi-periodic variability in active galactic nuclei in general, and in blazars in particular, is key to our understanding of the origin and nature of these objects as well as their cosmological evolution. PG 1553+113 is the first blazar showing an approximately two-year quasi-periodic pattern in its …