{
  "bibcode": "2006GCN..4498....1P",
  "body": "M. Perri (ASDC), A. Moretti (OAB), D. N. Burrows (PSU), R. Fink (GSFC),\nM. Ajello (MPE) report on behalf of the Swift XRT team:\n\nWe have analyzed the first 6 orbits of XRT data from GRB 060111B (trigger\n176918, GCN 4487). A ~13 ks Photon Counting mode image provides a refined\nXRT position:\n\nRA(J2000) =  19h 05m 42.23s,\nDec(J2000) = +70d 22m 35.8s\n\nwith an uncertainty of 3.6 arcsec (90% containment). This position is 1.1\narcsec away from the on-board XRT position (GCN 4487) and includes the\nlatest\nXRT boresight correction.  This position is 45 arcsec from the refined BAT\nposition (Tueller et al., GCN 4492) and 3.0 arcsec from the optical\nafterglow\nreported by Yanagisawa et al. (GCN 4496).\n\nThe X-ray light curve can be fit with a broken power-law with an initial\ndecay slope of -4.0+/-0.4, a break at T+139+/-7 s, and a post-break slope\nof -1.1+/-0.1.\n\nA power-law fit to the X-ray spectrum from T+88s to T+425s gave a photon\nindex of 2.1+/-0.3 and a column density of (2.0+/-0.9)e21 cm**-2. We note\nthe Galactic hydrogen column density in the direction of the burst is\n7.1e20cm**-2.\n\nIf the burst continues decaying at the current rate we estimate an XRT\ncount rate of 0.004 counts/s at T+24hr, which corresponds to an\nobserved 0.3-10.keV flux of 2e-13 ergs cm**-2 s**-1.",
  "circularId": 4498,
  "createdOn": 1137091041000,
  "email": "perri@asdc.asi.it",
  "subject": "GRB 060111B: Swift XRT refined analysis",
  "submitter": "Matteo Perri at ISAC/ASDC  <perri@asdc.asi.it>",
  "eventId": "GRB 060111B"
}