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MAXI/GSC detects renewed activity from SLX 1746-331

ATel #3098; H. Ozawa, F. Suwa, H. Negoro (Nihon U.), M. Serino (RIKEN), S. Ueno, H. Tomida, M. Kohama, M. Ishikawa (JAXA), T. Mihara, M. Sugizaki, Y. E. Nakagawa, T. Yamamoto, T. Saotome, M. Matsuoka (RIKEN), N. Kawai, M. Morii, K. Sugimori, R. Usui (Tokyo Tech), A. Yoshida, K. Yamaoka, S. Nakahira (AGU), H. Tsunemi, M. Kimura, H. Kitayama (Osaka U.), M. Nakajima, (Nihon U.), Y. Ueda, N. Isobe, S. Eguchi, K. Hiroi, M. Shidatsu (Kyoto U.), A. Daikyuji (Miyazaki U.), Y. Tsuboi, Uzawa, T. Matsumura, K. Yamazaki (Chuo U.) report on behalf of the MAXI team
on 6 Jan 2011; 16:54 UT
Credential Certification: Hitoshi Negoro (negoro@phys.cst.nihon-u.ac.jp)

Subjects: X-ray, Transient

he MAXI/GSC detected renewed activity from the black-hole candidate SLX 1746-331. The source has been detectable since 2010-Dec-27 UT (MJD=55557). X-ray intensity gradually increased, and once reached a peak around 2010-Dec-30 (MJD=55560). On Jan. 5, the source flux increased again. Note that the until 2010-Dec-30 source had been detected by a not-well calibrated detector with the high voltage of 1550 V, and that the source was at an undetectable area of the detectors on 2010-Dec-31. These observational conditions prevent us from determining more accurate dates of the beginning and peak dates of this outburst. The one-day averaged flux on 2010-Dec-30 was 83 +/- 31 mCrab in the 2-4 keV band and 92 +/- 29 mCrab in the 4-10 keV band. The preliminary spectral analysis shows that the spectrum on 2011 Jan 2-3 is dominated by a disk blackbody spectrum with 1.0+/-0.3 keV, consistent with previous observations (e.g., Kennea et al. ATel #1237), also suggesting that the source was in the soft state. SLX 1746-331 shows recurrent outbursts at intervals of a few years. The last outburst was in 2007 (Markwardt & Swank ATel #1235). The latest MAXI/GSC light curve and image are available at the following URL: http://maxi.riken.jp/top/index.php?cid=1&jname=j1749-332 Note that the source is so close (~ 1.3 deg) to another transient black-hole candidate H 1743-322, currently being in the off state, that the estimated flux of the one source not be free from the other in future.