Skip to main content
Testing. You are viewing the public testing version of GCN. For the production version, go to
New Announcement Feature, Code of Conduct, Circular Revisions. See news and announcements

GCN Circular 32767

GRB 221009A: LEIA X-ray Afterglow Detection
2022-10-16T02:21:05Z (2 years ago)
LEIA Team at NAOC/CAS <>
Y. Liu, C. Zhang, Z.X. Ling, H.Q. Cheng, C.Z. Cui, D.W. Fan, H.B. Hu,

M.H. Huang, C.C. Jin, D.Y. Li, H.Y. Liu, H. Sun, H.W. Pan, W.X. Wang,

Y.F. Xu, M. Zhang, W.D. Zhang, D.H. Zhao, and W. Yuan (NAOC, CAS),

report on behalf of the LEIA and Einstein Probe team:


LEIA (Lobster Eye Imager for Astronomy) has performed one

follow-up observation of GRB 221009A detected by Swift/BAT

(Dichiara et al., GCN 32632, Kennea et al., GCN 32635), Fermi-GBM

(Lesage et al., GCN 32642, Veres et al., GCN 32636), Fermi-LAT

(Bissaldi et al. GCN 32637, Pillera et al., GCN 32658), AGILE-MCAL

(Ursi et al., GCN 32650), AGILE-GRID (Piano et al. GCN 32657),

INTEGRAL SPI/ACS (Gotz et al., GCN 32660), Konus-Wind

(Frederiks et al., GCN 32668), HEBS (Liu et al., GCN 32751), at a 

redshift of z = 0.151 (de Ugarte Postigo et al., GCN 32648; 

Castro-Tirado et al., GCN 32686).


The pointed observation was conducted from 2022-10-12T05:31:48

to 2022-10-12T05:51:39 with a net exposure of 1012 s. The X-ray

afterglow of GRB 221009A is detected at a significance of 4.9 sigma.

Assuming an absorbed power-law model with a photon index of 2.0,

a Galactic absorption of 5.4 x 10^21 cm^-2 (Willingale et al. 2013;

GCN #32651), and an intrinsic absorption of 1.1 x 10^22 cm^-2 at a

redshift of 0.151 (GCN #32648), the unabsorbed flux in the 0.5 - 4.0 keV

band is (1.8+/-0.4) x 10^-10 ergs/cm^2/s.


LEIA (Zhang et al, ApJL submitted) is a soft X-ray monitor (0.5 - 4.0 keV)

with a FoV of 340 square degrees aboard the SATech-01 satellite of the CAS,

launched on July 27, 2022. The above result is preliminary and the final

result will be published elsewhere.
Looking for U.S. government information and services? Visit