A. Melandri (INAF-OAB), P. D'Avanzo (INAF-OAB), V. D'Elia (ASDC), D.N.
Burrows (PSU), T.G.R. Roegiers (PSU), L.M. McCauley (PSU), S.L. Gibson
(U. Leicester), J.P. Osborne (U. Leicester) and P.A. Evans (U.
Leicester) report on behalf of the Swift-XRT team:
Swift-XRT has performed follow-up observations of the
Swift/BAT-detected burst GRB 151122A (David Palmer et al. GCN Circ.
18637), collecting 3.0 ks of Photon Counting (PC) mode data between
T0+102.9 ks and T0+114.0 ks.
Two uncatalogued X-ray sources have been detected inside or close to
the Swift/BAT error region, however none of them is above the RASS
limit or shows definitive signs of fading. Therefore, at the present
time we cannot identify which, if any, is the afterglow. Details of
these sources are given below:
RA (J2000.0): 299.6973 = 19:58:47.35
Dec (J2000.0): -19.9063 = -19:54:22.8
Error: 4.7 arcsec (radius, 90% conf.)
Count-rate: 0.0100 �� 0.0023 ct s^-1
Flux: (4.24 �� 0.95)e-13 erg cm^-2 s^-1 (observed, 0.3-10 keV)
This source is 5.8" away from PMN J1958-1954, classified in SIMBAD as a
RA (J2000.0): 299.6668 = 19:58:40.03
Dec (J2000.0): -19.9360 = -19:56:09.5
Error: 4.9 arcsec (radius, 90% conf.)
Count-rate: (3.9 �� 1.6)e-3 ct s^-1
Flux: (1.57 �� 0.64)e-13 erg cm^-2 s^-1 (observed, 0.3-10 keV)
This source is 2.1" from HD 189004, a high proper-motion, K star.
Another uncatalogued was also detected, however this was too far from
the GRB position to be the afterglow.
The results of the XRT-team automatic analysis of the XRT observations,
including a position-specific upper limit calculator, are available at
This circular is an official product of the Swift-XRT team.