{
  "bibcode": "2007GCN..6112....1S",
  "body": "R.L.C. Starling (U Leicester), T. Sakamoto (NASA/GSFC), K.L. Page, M.R. \nGoad and P.A. Evans (U Leicester) report on behalf of the Swift-XRT team:\n\nWe have analysed the first four orbits (up to 18.8 ks after the BAT \ntrigger) of Swift XRT data for the faint X-ray afterglow of GRB 070219 \n(Sakamoto et al., GCN 6104). Using ~6 ks of Photon Counting (PC) mode data \nwe find the following astrometrically corrected XRT refined position (by \nmatching the UVOT images with the USNO-B1 catalogue):\n\nRA (J2000)  =  17h 20m 45.99s \nDec(J2000)  = +69d 22' 10.6\"\n\nwith an error radius of 3.6 arcseconds (90% confidence). This is 95.2, \n21.8 and 3.0 arcseconds away from the BAT refined, BAT initial and XRT \ninitial positions respectively.\n\nThe lightcurve appears to follow the canonical three-phase decay. It \ndecays with alpha_1~2.2, breaking at T_bk_1~330 s to alpha_2~0.3 and \nbreaking again at T_bk_2~9200 s to a slope of alpha_3~1.5.\n\nThe PC mode spectrum, summed over all the data collected thus far, is not \ntightly constrained, but can be fitted with a single power law of photon \nindex Gamma = 2 and a total absorbing column at z = 0 of nH = 1.3E21 cm-2, \nin excess of the Galactic value of 4.1E20 cm-2. The 0.3-10 keV observed \n(unabsorbed) flux is 9E-13 (1.2E-12) erg/cm2/s. There are too few counts \nfor a time-resolved spectral analysis, hence any spectral evolution \npresent cannot be measured.\n\nIf the decay continues with a slope of alpha = 1.5, the predicted count \nrate at 24 hours post-trigger is 5E-4 cts/s. This corresponds to an \nobserved (unabsorbed) flux of 2E-14 (3E-14) erg/cm2/s.\n\nThis circular is an official product of the Swift-XRT team.",
  "circularId": 6112,
  "createdOn": 1171896663000,
  "email": "rlcs1@star.le.ac.uk",
  "subject": "GRB 070219: XRT Refined Analysis",
  "submitter": "Rhaana Starling at U of Leicester  <rlcs1@star.le.ac.uk>",
  "eventId": "GRB 070219"
}