Multi-epoch VLBA observations of 3C 66A

¹ Shanghai Astronomical Observatory, Chinese Academy of Sciences, Shanghai 200030, PR China e-mail: zshen@shao.ac.cn
² Graduate School of Chinese Academy of Sciences, Beijing 100039, PR China
³ Joint Institute for Galaxy and Cosmology, SHAO and USTC, PR China
⁴ Faculty of Engineering, Gifu University, Gifu 501-1193, Japan
⁵ National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan
⁶ The Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, Sagamihara, Kanagawa 229-8510, Japan
⁷ Physics Department, Graduate School of Science, Ehime University, 2-5 Bunkyou, Matuyama, 790-8577, Japan

Received: 24 January 2007
Accepted: 16 March 2007

Abstract

We present the results of six-epoch Very Long Baseline Array (VLBA) observations of 3C 66A. The high-resolution Very Long Baseline Interferometer (VLBI) maps obtained at multi-frequency (2.3, 8.4, and 22.2 GHz) simultaneously enabled us to identify the brightest compact component with the core. We find that the spectrum of the core can be reasonably fitted by the synchrotron self-absorption model. Our VLBA maps show that the jet of 3C 66A has two bendings at about 1.2 and 4 mas from the core. We also give possible identifications of our jet components with the components in previous VLBA observations by analysing their proper motions. We find consistent differences of the position from the core in one component between different frequencies at six epochs.