First Results from the All-sky Monitor on the Rossi X-ray Timing Explorer

The all-sky monitor on the Rossi X-Ray Timing Explorer has been monitoring the sky in the 1.5–12 keV band since late February. The instrument consists of three coded-aperture cameras that can be rotated to view different regions by a motorized drive assembly. Intensities of 1100 known sources are obtained via least-squares fits of shadow patterns to the data and compiled to form X-ray light curves. Six orbital periodicities and four long-term periodicities, all previously known, have been detected in these light curves. Searches for additional sources have also been conducted. X-ray light curves for the Crab Nebula, Cyg X-1, 4U 1705244, GRO J1655240, and SMC X-1 are reported. They illustrate the quality of the results and the range of observed phenomena. Subject headings: instrumentation: detectors —X-rays: general —X-rays: stars