Dual-Frequency VSOP Observations of AO 0235+164
Abstract
AO 0235+164 is a very compact, flat spectrum radio source identified as a BL Lac object at a redshift of z=0.94. It is one of the most violently variable extragalactic objects at both optical and radio wavelengths. The radio structure of the source revealed by various ground-based VLBI observations is dominated by a nearly unresolved compact component at almost all available frequencies. Dual-frequency space VLBI observations of AO 0235+164 were made with the VSOP mission in January-February 1999. The array of the Japanese HALCA satellite and co-observing ground radio telescopes in Australia, Japan, China and South Africa allowed us to study AO 0235+164 with an unprecedented angular resolution at frequencies of 1.6 and 5 GHz. We report on the sub-milliarcsecond structural properties of the source. The 5-GHz observations led to an estimate of T_B > 5.8 x 10^{13} K for the rest-frame brightness temperature of the core, which is the highest value measured with VSOP to date.
Cite
@article{arxiv.astro-ph/0007347,
title = {Dual-Frequency VSOP Observations of AO 0235+164},
author = {S. Frey and L. I. Gurvits and D. R. Altschuler and M. M. Davis and P. Perillat and C. J. Salter and H. D. Aller and M. F. Aller and H. Hirabayashi},
journal= {arXiv preprint arXiv:astro-ph/0007347},
year = {2015}
}
Comments
8 pages, 8 figures, to appear in Publ. Astron. Soc. Japan