X-ray transient LXT 240402A: LEIA detection
Abstract
We report on a fast X-ray transient LXT 240402A detected by LEIA (Lobster Eye Imager for Astronomy) in 0.5-4 keV. The position of the source is R.A. = 245.438 deg, DEC = 25.800 deg with an uncertainty of 1.5 arcmin (radius, 90%C.L. statistical and systematic). The source was detected by LEIA at 2024-04-02T08:47:41 (UTC). The averaged 0.5-4 keV spectrum can be fitted with an absorbed power law (with the column density fixed to the galactic value of 3.4e20 cm^-2) with a photon index of 0.8 (-0.2/+0.2), giving an unabsorbed flux of ~2.6 (-0.4/+0.5) e-9 erg/s/cm2 in the 0.5-4 keV band. There are two peaks observed in the light curve. The transient event lasted for approximately 200 seconds with a peak flux of ~3e-8 erg/s/cm2 in 0.5-4 keV band. Within the error circle of LXT 240402A, there is a radio galaxy (NVSS J162146+254915) at a redshift of ~0.05 with a ROSAT flux of 2.3e-12 erg/s/cm2, which is fainter than the peak flux detected by LEIA by more than three orders of magnitude. Assuming that LXT 240402A is associated with NVSS J162146+254915, the average luminosity of the X-ray transient is esitimated to be 1.5e46 erg/s. More follow-up observations are encouraged to help explore the nature of this transient. LEIA (Zhang et al. 2022, ApJL, 941, 2; Ling et al. 2023, RAA, 23, 095007) is a soft X-ray Lobster-eye imager (0.5 - 4.0keV) with a FoV of 340 square degrees aboard the experimental satellite SATech-01 of the CAS, launched on July 27, 2022. The above result is preliminary and the final result will be published elsewhere.
- Publication:
-
GRB Coordinates Network
- Pub Date:
- April 2024
- Bibcode:
- 2024GCN.36016....1X