Swift/XRT discovery of multiple dust-scattering X-ray rings around GRB 221009A
ATel #15661; Andrea Tiengo(IUSS Pavia), Fabio Pintore (INAF IASF Palermo), Sandro Mereghetti, Ruben Salvaterra (INAF IASF Milano) on behalf of a larger collaboration
on 11 Oct 2022; 10:38 UT
Credential Certification: Andrea Tiengo (andrea.tiengo@iusspavia.it)
Subjects: X-ray, Gamma-Ray Burst
Swift/XRT observed GRB221009A (GCN #32632, #32635, GCN #32636, #32637) in PC mode three times (Obs.ID: 01126853004, 01126853005, 01126853006) between 2022-10-10 14:08:49 UT and 2022-10-11 01:22:52 UT, for a net exposure time of 7464.5 s.
The stacked Swift/XRT image in the 0.3-10 keV energy band shows the presence of a complex system of at least 9 bright expanding rings with radii from about 2.5 to 7.5 arcmin. We adopted the method described in Tiengo & Mereghetti (2006, A&A 449, 203) to derive the following distances of the dust clouds: 179.3 +/- 0.7 pc, 290 +/- 5 pc, 406.2 +/- 0.9 pc, 467.6 +/- 1.5 pc, 554 +/- 2 pc, 714 +/- 1 pc, 1094 +/- 24 pc, 2092 +/- 22 pc and 3635 +/- 36 pc.