The X-Ray and Optical Activity of the Low Mass X-Ray Binary Scorpius X-1

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Session 11 -- Novae
Display presentation, Monday, 9, 1995, 9:20am - 6:30pm

[11.05] The X-Ray and Optical Activity of the Low Mass X-Ray Binary Scorpius X-1

C.L. Williams, B.J. McNamara, T.E. Harrison (NMSU), B.A. Harmon (MSFC)

We present X-ray and optical observations of the low mass X-ray binary (LMXB) Scorpius X-1 (V818 Sco). The X-ray data are obtained using the BATSE Spectroscopy Detectors on the Compton Gamma Ray Observatory. With its all-sky coverage, the BATSE instrument has allowed for nearly continuous monitoring of Sco X-1 since the launch of CGRO in April 1991. We present the X-ray data for 823 days, through the end of July 1994. The resulting light curve, made up of approximately 13,000 flux measurements, constitutes the longest X-ray light curve of Sco X-1, or any LMXB, ever obtained. Such a data base allows the investigation of the X-ray flux of Sco X-1 on never before monitored time-scales. We have developed a method of calibrating the BATSE detectors to a single detector response using the X-ray data. From the combined self-consistent histogram, we can estimate the amount of time Sco X-1 spends in its active flaring state versus the time spent in the quiescent state. We also present over 2000 optical observations of Sco X-1 covering the same time period. These data allow correlative studies to be undertaken. During May and June of 1994, high-speed optical photometry of Sco X-1 was obtained at Cerro Tololo Inter-American Observatory. This database contains several X-ray/optical correlated flaring episodes as well as anti-correlated activity, which will allow constraints to be placed on the binary system geometry and emission mechanisms.

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