{
"subject": "GRB 101112A - XRT source detection/analysis",
"bibcode": "2010GCN.11399....1E",
"createdOn": 1289640513000,
"circularId": 11399,
"submitter": "Phil Evans at U of Leicester ",
"email": "pae9@star.le.ac.uk",
"body": "P.A. Evans (U. Leicester) and H. A. Krimm (CRESST/GSFC/USRA),\nreport on behalf of the Swift-XRT team:\n\nWe have analysed 5.6 ks of XRT data for GRB 101112A (Gotz et al. GCN Circ.\n11396), from 6215 s to 18.4 ks after the INTEGRAL trigger. The data are entirely \nin Photon Counting (PC) mode. We find an uncatalogued, fading point source at \nRA, Dec=292.2295, 39.3531 which is equivalent to:\n\nRA(J2000.0): 19h 28m 55.08s\nDec (J2000.0): +39d 21' 11.0\"\n\nwith an estimated uncertainty of 4 arcsec (radius, 90% confidence). This \nposition is 38 arcsec from the INTEGRAL position, and 2.4 arcsec from the \noptical afterglow of Guidorzi et al (GCN Circ 11397), in agreement with both of \nthese positions.\n\nThe X-ray light curve can be modelled with a power-law decay with a decay index\nof alpha=0.9 (+/-0.6). A spectrum formed from the PC mode data can be fitted\nwith an absorbed power-law with a photon spectral index of 2.2 (+/-0.4). The\nbest-fitting absorption column is 2.0 (+1.2, -0.7) x 10^21 cm^-2, consistent\nwith the Galactic value of 1.2 x 10^21 cm^-2 (Kalberla et al. 2005). The counts\nto observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this\nspectrum is 3.7 x 10^-11 (5.9 x 10^-11) erg cm^-2 count^-1.\n\nIf the light curve continues to decay with a power-law decay index of 0.9, the\ncount rate at T+24 hours will be 3.7 x 10^-3 count s^-1, corresponding to an\nobserved (unabsorbed) 0.3-10 keV flux of 1.4 x 10^-13 (2.2 x 10^-13) erg cm^-2 s^-1.\n\nThe results of the XRT-team automatic analysis are available at\nhttp://www.swift.ac.uk/xrt_products/00020149.\n\nThis circular is an official product of the Swift-XRT team."
}