Multifrequency interferometer and radio continuum monitoring observations of CTA 102^*

¹ European Southern Observatory, Casilla 19001, Santiago 19, Chile
² Observatorio Cerro Calan, Universidad de Chile, Santiago, Chile
³ Tuorla Observatory, Väisäläntie 20, 21500 Piikkiö, Finland
⁴ Metsähovi Radio Observatory, Metsähovintie 114, 02540 Kylmälä, Finland
⁵ Department of Physical Sciences, University of Turku, 20100 Turku, Finland
⁶ Center for Imaging Technologies, Halmstad University, 301 18 Halmstad, Sweden

Corresponding author: F. T. Rantakyrö, frantaky@eso.org

Received: 12 March 2002
Accepted: 31 March 2003

Abstract

This paper represents the work of several years of observation of CTA 102 with both single dish telescopes and interferometric arrays, covering wavelengths from 1.2 cm to 1.3 mm. The resolution of the maps covers an order of magnitude from 0.5 mas to 50 μas. The images presented demonstrate the rapid structural changes in this source. These rapid structural changes correlates with the outbursts seen in the total flux, turnover frequency and in the spectral index. We have calculated the Brightness Temperatures of the components (T_B) directly from the determined component sizes and also using the logarithmic variability amplitudes and timescales to calculate the s. Both the methods yielded measurements of source frame T_Bs no higher than ~a K. We find that the observed average proper motion is ~ mas/yr, which corresponds to an apparent transverse velocity of c.