MAXI/GSC detection of an X-ray activity from HMXB IGR J19140+0951, or a new X-ray transient MAXI J1915+099
ATel #16665; M. Serino (AGU), M. Nakajima, H. Negoro (Nihon U.), T. Mihara (RIKEN), Y. Kudo, H. Shibui, K. Takagi, H. Takahashi, K. Tatano, H. Nishio (Nihon U.), T. Kawamuro, S. Yamada, S. Wang, T. Tamagawa, N. Kawai, M. Matsuoka (RIKEN), T. Sakamoto, S. Sugita, Y. Kawakubo, H. Hiramatsu, H. Nishikawa, Y. Kondo, A. Yoshida (AGU), Y. Tsuboi, H. Sugai, N. Nagashima (Chuo U.), M. Shidatsu, Y. Niida (Ehime U.), I. Takahashi, M. Niwano, N. Higuchi, Y. Yatsu (Tokyo Tech), S. Nakahira, S. Ueno, H. Tomida, M. Ishikawa, S. Ogawa, M. Kurihara (JAXA), Y. Ueda, Y. Okada (Kyoto U.), M. Yamauchi, Y. Otsuki, T. Hasegawa, M. Nishio (Miyazaki U.), K. Yamaoka (Nagoya U.), M. Sugizaki (NAOC), W. Iwakiri (Chiba U.)
on 21 Jun 2024; 15:56 UT
Distributed as an Instant Email Notice Transients
Credential Certification: Motoko Suzuki (motoko@crab.riken.jp)
Subjects: X-ray, Transient
Referred to by ATel #: 16666
The MAXI/GSC nova alert system triggered an uncatalogued X-ray transient source at 11:41 UT on 2024 June 20.
Assuming that the source flux was constant over the transits between
2024-06-19T15:29 and 2024-06-21T07:52,
we obtain the source position at (R.A., Dec) = (288.856 deg, 9.911 deg) = (19 15 25, +09 54 39) (J2000)
with a statistical 90% C.L. elliptical error region
with long and short radii of 0.24 deg and 0.22 deg, respectively.
The roll angle of long axis from the north direction is 138.0 deg counterclockwise.
There is an additional systematic uncertainty of 0.1 deg (90% containment radius).
The X-ray flux averaged over the scan was 33 +- 5 mCrab (4.0-10.0keV, 1 sigma error).
The error region with systematic uncertainty is close to the high-mass X-ray binary IGR J19140+0951 (Sidoli et al. 2016).
The Swift/BAT light curve of IGR J19140+0951, however, does not shows any significant activity, yet
(https://swift.gsfc.nasa.gov/results/transients/IGRJ19140p0951/).
Thus, we also tentatively name the source MAXI J1915+099 until the identification as IGR J19140+0951.
Followup observations are encouraged.
