MAXI/GSC detection of renewed activity from GX 339-4
ATel #17484; H. Negoro, M. Nakajima, K. Takagi, H. Takahashi, H. Nishio (Nihon U.), T. Mihara, T. Tamagawa, N. Kawai, M. Matsuoka (RIKEN), T. Sakamoto, M. Serino, S. Sugita, Y. Kawakubo, H. Hiramatsu, Y. Kondo, A. Yoshida (AGU), Y. Tsuboi, H. Sugai, N. Nagashima, Y. Ishihara (Chuo U.), M. Shidatsu, C. Kang, T. Nakamoto, M. Uenishi, T. Usuki, S. Yatsuzuka (Ehime U.), I. Takahashi, Y. Yatsu (Science Tokyo), S. Nakahira, S. Ueno, H. Tomida, M. Ishikawa, S. Ogawa, M. Kurihara (JAXA), Y. Ueda, K. Fujiwara (Kyoto U.), M. Yamauchi, M. Nishio, C. Hiraizumi (Miyazaki U.), K. Yamaoka (Nagoya U.), M. Sugizaki (Kanazawa U.), W. Iwakiri (Chiba U.), T. Kawamuro (Osaka U.), and S. Yamada (Tohoku U).
on 8 Nov 2025; 08:47 UT
Credential Certification: Hitoshi Negoro (negoro@phys.cst.nihon-u.ac.jp)
Subjects: X-ray, Black Hole
Referred to by ATel #: 17653
The black-hole X-ray binary GX 339-4 exhibited a new outburst from August 9 2025 (Saikia et al. ATel #17327). MAXI GSC light curves obtained with the image-fit method show that the 2-20 keV X-ray flux increased relatively rapidly after the EP FXT detection on August 12 (Zhao et al. ATel #17330), and peaked at approximately 28 mCrab on August 21 (MJD 60908). The X-ray flux decreased gradually, and the GSC had not detected the source in one day since September 2 (MJD 60920).
The 2-10 keV X-ray flux gradually increased again from around October 17 (MJD 60965), reaching approximately 20 mCrab on November 4-5. This renewed activity might be a continuation of the low-level activity observed from August.
MAXI GSC data for GX 339-4
