<title>In-orbit performance and calibration of the Rossi X-ray Timing Explorer (RXTE) Proportional Counter Array (PCA)</title>

Abstract

The proportional counter array (PCA) is designed to perform microsecond timing of bright galactic sources and broad band, confusion limited, studies of faint extragalactic sources in the 2 - 60 keV x-ray band. The PCA was launched as part of the Rossi X-ray Timing Explorer (RXTE) satellite into a circular orbit of altitude 580 km and 23 degrees inclination on December 30, 1995. The mission contains three experiments: a set of large area xenon proportional counters sensitive from 2 - 60 keV (proportional counter array: PCA), a set of large area sodium iodide scintillators sensitive from 15 - 200 keV (high energy x-ray timing experiment: HEXTE), and three wide field of view scanning detectors which monitor most of the sky each orbit (all sky monitor: ASM). The goals of the mission are summarized by Swank et al. We present performance and calibration data on the measured and predicted in-orbit background, energy response, relative and absolute timing performance, and the operational possibilities made available with the high performance experiment data system (EDS) designed and built by MIT.