The APT was used together with the Very Long Baseline Array (VLBA) and the European VLBI Network (EVN) to monitor the X-ray binary system Sco X-1 over a 56 hour period from June 11-13, 1999.
NRAO has a press release describing the results, and with a link to a "movie" showing the evolution of the source over the 56 hours. The Australia Telescope Compact Array, and Ceduna, Hartebeesthoek, Kashima, Mopra, Parkes, and Shanghai telescopes of the Asia-Pacific Telescope participated in these observations, which were made at a frequency of 5 GHz.
The results are described in two scientific papers, Scorpius X-1: Energy Transfer from the Core to the Radio Lobes by E.B. Fomalont, B.J. Geldzahler, and C.F. Bradshaw, in the Astrophysical Journal, 553, L27 (2001), and Scorpius X-1: The Evolution and Nature of the Twin Compact Radio Lobes by E.B. Fomalont, B.J. Geldzahler, and C.F. Bradshaw, in the Astrophysical Journal, 558, 283 (2001).
Many APT telescopes have been participating in VSOP (VLBI Space Observatory Programme) observations since the launch of the HALCA satellite in 1997. APT telescopes have been an important contributor to VSOP Survey Program observations in particular.
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Last Modified: 30 July 2002