Title: XRISM/Xtend Transient Search (XTS) detected an X-ray brightening from XRISM J0602-4006
ATel #17794; A. Miyamoto (UOsaka), K. Fukushima (TUS), Y. Kanemaru, A. Miyamoto, Y. Omiya, Y. Uchida, T. Yoneyama (JAXA), M. Audard (U. de Geneve), E. Behar (Technion), T. Hakamata (UOsaka), S. Inoue (Kyoto U.), Y. Ishihara (Chuo U.), C. Kang (Ehime U.), T. Kiyomoto (Saitama U.), T. Kohmura (TUS), H. Kuramoto (UOsaka), Y. Maeda (JAXA), H. Matsumoto (UOsaka), M. Mizumoto (UTEF), Y. Motogami (Saitama U.), T. Narita (RIKEN), M. Nobukawa (NUE), H. Noda (Tohoku U.), S. Ogawa (TUS), Y. Sakamoto (Tohoku U.), M. Shidatsu (Ehime U.), H. Takahashi (Hiroshima U.), T. Takagi (Ehime U.), S. Takatsuka (UOsaka), F. Takisawa (Ehime U.), Y. Terada (Saitama U., JAXA), Y. Terashima (Ehime U.), Y. Tsuboi (Chuo U.), H. Uchida (Kyoto U.), A. Yoshimoto (NWU), M. Yoshimoto (Ehime U.)
on 11 May 2026; 14:03 UT
Credential Certification: Kotaro Fukushima (kxfukushima@gmail.com)
XRISM/Xtend Transient Search (XTS) identified an additional X-ray transient from the source XRISM J0602-4006, potentially corresponding to 2CXO J060212.4-400619 (ATel #17785), on 2026-05-10 TT. A plausible counterpart is the star UCAC2 14546266 with a distance of ∼ 1.3 kpc.
The brightening lasted from 2026-05-10 at ∼ 08:19 TT to 2026-05-10 at ∼ 15:16. The peak flux is calculated as 1 × 10-12 erg s-1 cm-2 (0.4 – 10.0 keV). A systematic error of roughly 20% should be taken into account. The corresponding luminosity is 2 × 1032 erg s-1 by assuming the distance to XRISM J0602-4006 of 1.3 kpc. The peak luminosity is approximately twice that of the previous brightening reported in ATel #17785.
We derived the above systematic error for the flux by comparing our derived values for the sources detected with XTS in several observations with those for the corresponding X-ray counterparts. We estimated the systematic error for the source position from the separations between the detected sources and their corresponding counterparts in the same field of view.
