XRISM/Xtend Transient Search (XTS) detected an X-ray flare from XRISM J0534-6600 in BSDL 2344 region of LMC

Abstract

XRISM/Xtend Transient Search (XTS) detected an X-ray flare from BSDL 2344 region in Large Magellanic Cloud (LMC) on 2025-05-30 TT. The source position is determined to be (R.A., Dec.) = (83.570, -66.008), with a systematic error of ∼ 40 arcsec. Plausible counterparts are X-ray sources 4XMM J053423.3-660024 or 1eRASS J053423.5-660030. All statistical uncertainties in this report are provided as a 90% confidence level unless stated otherwise. XRISM/XTS detected the flare at the peak time on 2025-05-30 at ∼ 15:56 TT, and the flare decayed in ∼ 4,000 sec. The peak flux is calculated as 3 × 10⁻¹³ erg s⁻¹ cm⁻² (0.4 – 10.0 keV). A systematic error of roughly 20% should be added to the statistical error. The corresponding luminosity is 3 × 10³⁴ erg s⁻¹ by assuming the distance at 50 kpc in LMC. 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 with the corresponding counterparts in the same field of view.