The First MAXI/GSC Catalog in the High-Galactic Latitude Sky

We present the first source catalog of the Monitor of All-sky X-ray Image (MAXI) mission at high Galactic latitudes (vertical bar b vertical bar > 10 degrees), produced from the first 7 months data (2009 September 1 to 2010 March 31) of the Gas Slit Camera (GSC) in the 4-10 keV band. We develop a systematic analysis procedure to detect faint sources from the MAXI data, by utilizing maximum likelihood image fitting method, where the image response, background, and detailed observational condition are taken into account. Our catalog consists of 143 X-ray sources above 7 sigma significance level down to a limiting sensitivity of 1.5x10(-11) ergs cm(-2) s(-1). From cross-correlation with other catalogs, we identify 38 Galactic/LMC/SMC objects, 48 galaxy clusters, and 51 AGNs including 12 blazars. The source counts of extragalactic objects are in good agreement with the HEAO-1 A-2 results. The datails are given in Hiroi et al. (2011, PASJ in press).