Abstract
We present three epochs of VSOP observations of the BL Lac object2007+777 at 5 GHz. Compared with the ground-based VLBA data, the space baselines with HALCA clearly reveal a more detailed and finer source structure. Mainly based on the quite uniform and circular UV-coverages of the VLBA, and using a new cross-self calibration method, we have found evidence for weak structural changes on a timescale of two weeks in the core region of this intraday variable source. The physical causes for these variations are discussed.
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Jin, C., Krichbaum, T., Witzel, A. et al. VSOP observations of the BL Lac object 2007+777. Astrophysics and Space Science 278, 97–100 (2001). https://doi.org/10.1023/A:1013199621452
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DOI: https://doi.org/10.1023/A:1013199621452