SRG/ART-XC detection of the new X-ray transient SRGA J132851.0-632350 or renewed activity from IGR J13290-6323
ATel #17033; I. Mereminskiy, A. Semena, S. Molkov, A. Lutovinov, A. Tkachenko, A. Shtykovsky (IKI RAS, Moscow)
on 12 Feb 2025; 09:32 UT
Credential Certification: Andrey Semena (san@iki.rssi.ru)
Subjects: X-ray, Transient
During the on-going all-sky survey, on Feb.11, 2025, the Mikhail Pavlinsky ART-XC telescope onboard the SRG observatory detected a bright X-ray transient at the position of RA, Dec = 202.2127, -63.3974 (J2000, positional uncertainty is 15", 90%). Observed X-ray flux was 2.6(±0.6)x10-11 erg cm-2 s-1 in the 4-12 keV band.
The position of the transient is 1.5' of the position of the historical X-ray transient IGR J13290-6323, which was detected by INTEGRAL during a short period of activity (3 days) in 2003 (Krivonos+07) and also detected in time-averaged INTEGRAL maps of the Galactic plane (Krivonos+22), indicating presence of a continuous low-level activity. This offset is compatible with the typical INTEGRAL localization accuracy of ≈2' (68%). We therefore suggest that the observed transient could be a new outburst from IGR J13290-6323, although this connection needs to be proven in future. No sources were detected at this position during previous ART-XC all-sky surveys, nor in eROSITA survey.
We initiated rapid follow-up observations with Swift/XRT in order to obtain better localization and the source was observed on Feb 12 (MJD 60718.15). There is a single bright source in the field, located at RA, Dec = 202.20525, -63.39366 (enhanced position, 3.4", 90%), at 18" offset with respect to the ART-XC position. We performed initial spectral analysis, applying a simple absorbed power-law model. The source is heavily absorbed (NH≈(5±3)x1023 cm-2), while the spectral slope is poorly constrained 2.1(-1.7,+2.0). The measured flux is about 1.3x10-11 erg cm-2 s-1 in the 0.5-10 keV band, similar to what is observed in a harder band by ART-XC.
There is a bright NIR/IR (Ks≈11.9 mag) source 2MASS J13284925-6323390 inside the XRT localization region, which shows significant reddening (J-Ks≈2) and variability (LPV classification from VIVACE, Molnar+22) as it would be expected for absorbed X-ray source. Additional observations are needed to verify this association.
The Mikhail Pavlinsky ART-XC telescope is the X-ray telescope on board the SRG observatory which was launched from the Baikonur cosmodrome on 13 July 2019 by the Proton rocket.
We thank the Swift team for their rapid response.
