GCN Circular 6065
Subject
GRB 070129: dust-scattered X-ray halo detected by Swift/XRT
Date
2007-01-31T14:31:35Z (17 years ago)
From
Sandro Mereghetti at IASF/CNR <sandro@iasf-milano.inaf.it>
G. Vianello (INAF, IASF-Milano & Univ. dell'Insubria), A. Tiengo, S.
Mereghetti (INAF, IASF-Milano) report:
We discovered a faint dust scattering halo in the Swift XRT Photon
Counting mode data of GRB 070129. The halo consists of a partial ring of
radius ~2 arcmin located to the North-West of the GRB afterglow position.
Analysis of the dynamical image (see Tiengo & Mereghetti 2006 A&A 449,
203) covering the period from T0+4700s to T0+7300s (where T0 is the BAT
trigger time, as reported in GCN 6053) indicates that the halo is
expanding and leads to an estimate of ~300 pc for the distance of the dust
layer responsible for the scattering.
Dust maps (Schlegel, Finkbeiner, & Davis 1998, ApJ, 500, 525) show a
diffuse structure in the direction indicated by the partial ring, and a
total Galactic extinction of A_v~0.4.