{
  "bibcode": "2005GCN..4169....1R",
  "body": "J. Racusin, J. Kennea, D. Fox, D. Burrows, N. Cucchiara (PSU), P. Schady \n(MSSL), A. Wells (U. Leicester), N. Gehrels, T. Sakamoto (GSFC), C. \nKouveliotou (MSFC), S. Patel (MSFC) on behalf of the Swift XRT team:\n\nWe have analyzed the observations of the X-ray afterglow (Racusin et al., \nGCN 4141, Butler et al, GCN4165) of GRB 051022 (Olive et al., GCN 4131) \nbeginning approximately 3.5 hours after its discovery by HETE on October \n22 and continuing for 4.8 days.  We find the early decay slope of 1.33 +/- \n0.07 (Butler et al, GCN 4165) extends to 2.9 +/- 0.2 days after the burst, \nafter which it steepens to a late time decay slope of 3.6 +/- 0.4. \nFurther observations are planned.\n\nGiven the redshift of 0.8 (Gal-Yam et al., GCN 4156) and the different \nmeasured fluences and Epeak by Konus-Wind (Golenetskii et al., GCN 4150) \nand HETE (Doty et al, GCN 4145), assuming n=0.1 cm^-3 and our jet break \ntime, we calculate the following Eiso, Egamma, and jet opening angles:\n\nHETE:\nalpha=-1.2, beta=-10.0, Epeak=306 keV, 2-400 keV fluence=1.6e-4 erg cm-2\nEiso = 3.8e53 erg\nJet opening angle = 4.3 degrees\nEgamma = 1.1e51 erg\n\nKonus-Wind:\nalpha=-1.2, beta=-10.0, Epeak=510 keV, 20 keV-2 MeV fluence=2.6e-4 erg cm-2\nEiso = 3.1e53 erg\nJet opening angle = 4.4 degrees\nEgamma = 9.1e50 erg",
  "circularId": 4169,
  "createdOn": 1130433041000,
  "email": "racusin@astro.psu.edu",
  "subject": "GRB051022: Swift XRT measurement of jet break",
  "submitter": "Judith Racusin at PSU  <racusin@astro.psu.edu>",
  "eventId": "GRB 051022"
}