Imaging strong blazars with space VLBI

摘要

The RadioAstron mission has obtained a series of detailed multi-frequency images of the brightest blazars of the radio sky concentrated in three key science programs. We present here results of the program on powerful jets in blazars. In the first two years of the mission, observations of compact relativistic jets in 0836+710, 3C345, 3C273, and 4C+69.21 were made at λλ 18, 6, and 1.3 cm. The resulting images have revealed compact emitting regions with brightness temperature in excess of 10~(13) K and a complex jet structure that can be explained by plasma instability developing in a relativistic outflow.We present here some highlights of these space-VLBI observations, designed to resolve the innermost regions in these powerful targets and address some of the still unanswered questions on their physical nature.