MAXI/GSC detection of renewed X-ray activity of the neutron star X-ray binary XTE J1709-267
ATel #9108; S. Nakahira (JAXA), T. Mihara M. Matsuoka (RIKEN), H. Negoro (Nihon U.), S. Ueno, H. Tomida, M. Ishikawa, Y. E. Nakagawa, Y. Sugawara (JAXA), M. Sugizaki, M. Serino, W. Iwakiri, M. Shidatsu, J. Sugimoto, T. Takagi,(RIKEN), N. Kawai, N. Isobe, S. Sugita, T. Yoshii, Y. Tachibana, Y. Ono, T. Fujiwara (Tokyo Tech), A. Yoshida, T. Sakamoto, Y. Kawakubo, Y. Kitaoka (AGU), H. Tsunemi, R. Shomura (Osaka U.), M. Nakajima, K. Tanaka, T. Masumitsu, T. Kawase (Nihon U.), Y. Ueda, T. Kawamuro, T. Hori, A. Tanimoto (Kyoto U.), Y. Tsuboi, Y. Nakamura, R. Sasaki (Chuo U.), M. Yamauchi, K. Furuya (Miyazaki U.), K. Yamaoka (Nagoya U.) report on behalf of the MAXI team
on 2 Jun 2016; 09:03 UT
Credential Certification: Satoshi NAKAHIRA (nakahira@crab.riken.jp)
Subjects: X-ray, Binary, Neutron Star
We report on a detection of X-ray outburst from XTE J1709-267
triggered by the MAXI/GSC nova alert system at 12:25 on 2016 May 31.
The MAXI/GSC 2-6 keV X-ray flux on May 31 is 210 mCrab, which is brighter
than the peak flux of the previous outburst in July 2012 (160 mCrab in 2-6 keV; Atel #5319, Asai, K. et al, PASJ 67, 92, 2015).
Since no valid data was obtained with MAXI/GSC from May 23 to May 30
(due to invisible area for near the ISS rotation pole and obscuration
of ISS structures) we could not find out the exact onset time of
this outburst. Swift/BAT transient monitor data, however, suggest
an enhancement of hard X-ray after May 27.
The MAXI/GSC energy spectrum integrated from May 31.5 to June 1.5 can be
modeled with an absorbed black body with kTbb=1.23 keV (χ2ν = 1.20 for 72 dof ).
Adding a Comptonized hard-tail by using nthcomp model improves the goodness of the fit
above 10 keV (χ2ν = 0.90 for 71 dof ) and yields kTbb=0.76±0.15
with a fixed kTe of 5 keV.
MAXI/GSC light curve is available at
http://maxi.riken.jp/top/index.php?cid=1&jname=J1709-266
