Radio and X-ray states in the X-ray binary Scorpius X-1

Radio observations of Sco X-1 were made on March 10-11, 1989 with the VLA, the WSRT, and the Australian Telescope as part of a multiwavelength campaign with the Ginga X-ray satellite, the IUE satellite, and other ground-based instruments. Two source states were detected in the radio and X-ray data, with Sco X-1 being radio-quiet when it was in the X-ray flaring branch and radio-loud when it was in the X-ray normal branch, the same type of radio-X-ray correlation seen in the Z-sources GX 17 + 2 and Cyg X-2. Both radio-quiet and radio-loud states showed radio spectrum changes indicating a multicomponent radio source, where the high-frequency component is variable on time scales of 2-3 hr. 14 refs.