Alignment calibration of MAXI/GSC

Monitor of All-sky X-ray Image (MAXI) is the unprecedentedly sensitive all-sky X-ray monitor. MAXI is mounted on the Exposed Facility of Japanese Experiment Module on the International Space Station. MAXI has two types of slit and slat X-ray cameras: Gas Slit Camera (GSC) and Solid-state Slit Camera (SSC) sensitive for 2-30 and 0.5-12 key bands, respectively. We calibrated the alignment of the GSC, then the position accuracy of X-ray point sources was significantly improved from about 1 degrees to 0.2 degrees (90% containment radius). This improvement of the position accuracy is essentially important to achieve various scientific objectives of MAXI. (C) 2010 Elsevier B.V. All rights reserved.