The First MAXI/GSC Catalog in the High Galactic-Latitude Sky
astro-ph.HE
/ Authors
Kazuo Hiroi, Yoshihiro Ueda, Naoki Isobe, Masaaki Hayashida, Satoshi Eguchi, Mutsumi Sugizaki, Nobuyuki Kawai, Hiroshi Tsunemi, Masaru Matsuoka, Tatehiro Mihara
and 25 more authors
Kazutaka Yamaoka, Masaki Ishikawa, Masashi Kimura, Hiroki Kitayama, Mitsuhiro Kohama, Takanori Matsumura, Mikio Morii, Yujin E. Nakagawa, Satoshi Nakahira, Motoki Nakajima, Hitoshi Negoro, Motoko Serino, Megumi Shidatsu, Tetsuya Sootome, Kousuke Sugimori, Fumitoshi Suwa, Takahiro Toizumi, Hiroshi Tomida, Yohko Tsuboi, Shiro Ueno, Ryuichi Usui, Takayuki Yamamoto, Kyohei Yamazaki
/ Abstract
We present the first unbiased source catalog of the Monitor of All-sky X-ray Image (MAXI) mission at high Galactic latitudes ($|b| > 10^{\circ}$), produced from the first 7-month data (2009 September 1 to 2010 March 31) of the Gas Slit Camera in the 4--10 keV band. We develop an analysis procedure to detect faint sources from the MAXI data, utilizing a maximum likelihood image fitting method, where the image response, background, and detailed observational conditions are taken into account. The catalog consists of 143 X-ray sources above 7 sigma significance level with a limiting sensitivity of $\sim1.5\times10^{-11}$ ergs cm$^{-2}$ s$^{-1}$ (1.2 mCrab) in the 4--10 keV band. Among them, we identify 38 Galactic/LMC/SMC objects, 48 galaxy clusters, 39 Seyfert galaxies, 12 blazars, and 1 galaxy. Other 4 sources are confused with multiple objects, and one remains unidentified. The log $N$ - log $S$ relation of extragalactic objects is in a good agreement with the HEAO-1 A-2 result, although the list of the brightest AGNs in the entire sky has significantly changed since that in 30 years ago.