MAXI/GSC detection of a superburst from the neutron star SAX J1828.5-1037
ATel #3760; . Asada, H. Negoro (Nihon U.), M. Sugizaki, M. Matsuoka, T. Mihara, M. Serino, S. Nakahira, T. Yamamoto, T. Sootome (RIKEN), S. Ueno, H. Tomida, M. Kohama, M. Ishikawa (JAXA), N. Kawai, M. Morii, K. Sugimori, R. Usui, T. Toizumi, Y. Aoki, S. Song (Tokyo Tech), A. Yoshida, K. Yamaoka (AGU), H. Tsunemi, M. Kimura, H. Kitayama (Osaka U.), M. Nakajima, F. Suwa, H. Sakakibara (Nihon U.), Y. Ueda, K. Hiroi, M. Shidatsu (Kyoto U.), Y. Tsuboi, T. Matsumura, K. Yamazaki (Chuo U.) M. Yamauchi, Y. Nishimura, T. Hanayama (Miyazaki U.) report on behalf of the MAXI team
on 13 Nov 2011; 11:29 UT
Credential Certification: Hitoshi Negoro (negoro@phys.cst.nihon-u.ac.jp)
Subjects: X-ray, Binary, Neutron Star, Transient
Referred to by ATel #: 4622
MAXI/GSC detected a transient bright source from the position at
(R.A., Dec.) = (277.237, -10.753) = (18 28 57, -10 45 11)(J2000)
with a systematic uncertainty of 0.2 deg.
The source has been detected since the scan transit at
2011-11-12T08:41 (UT), at which the source flux is about 0.26+-0.03 Crab
in the 4-10 keV band.
It is possible that the activity started between this and the previous scan
transit at 2011-11-12T07:09.
The source flux decreases almost exponentially with a time constant of
about 0.1 day, implying that this activity originates from a superburst.
The position is consistent with the bursting neutron star SAX J1828.5-1037
(Cornelisse et al. 2002, A&A, 392, 885). SAX J1828.5-1037
exhibited an outburst in October, 2008 (Degenaar & Wijnands ATel #1831),
and the peak flux observed with Swift/XRT was 2.29e-10 erg/s/cm2
(Campana 2009, ApJ 699, 1144).
This detection is likely to be the first detection of the superburst
from this source. The possibility of another source can not be excluded,
however. Follow-up observations are strongly encouraged.
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