X-ray activity of the transient burster IGR J17498-2921 detected with INTEGRAL
ATel #15996; S. A. Grebenev, S. S. Bryksin, R. A. Sunyaev (Space Research Institute, Moscow)
on 19 Apr 2023; 20:17 UT
Credential Certification: Sergei Grebenev (sergei@hea.iki.rssi.ru)
Subjects: Infra-Red, X-ray, Request for Observations
Referred to by ATel #: 15998
During INTEGRAL observations of the Galactic center field on April 13-15, 2023, the transient X-ray burster IGR J17498-2921 was found in a bright X-ray state for the first time since its discovery in August-September, 2011.
The source has been discovered on August 11, 2011 (ATel \#3551, \#3555), has been recognized as a millisecond pulsar on August 13 (ATel \#3556) and as an X-ray burster on August 14 (ATel \#3560). It has been estimated to be at a distance of 7.6 kpc (ATel \#3568), its orbital period has been measured to be 3.84 h (ATel \#3601). The source has returned to quiescence at the end of September
2011 (ATel \#3661).
According to the current (April 13-15) INTEGRAL observations with the IBIS/ISGRI telescope the 28-84 keV flux from IGR J17498-2921 is again equal to 18.2+/-1.3 mCrab. Note that the source has not been detected during our recent quasi-regular observations of the region lasted since February 10 till April 6, the 3-sigma upper limit for its flux was 2.5 mCrab in the 28-84 keV band.
We encourage further observations of this interesting source at all wavelengths.
