{
  "bibcode": "2009GCN..9674....1V",
  "body": "L. Vetere (PSU) reports on behalf of the Swift-XRT team:\n\nWe have analysed ~2 ks of XRT data for GRB 090715B (Vetere et al. GCN\nCirc. 9668), from 52 s to 10.2 ks after the BAT trigger. The data\ncomprise 471 s in Windowed Timing (WT) mode with the remainder in Photon\nCounting (PC) mode. The refined XRT position for this burst is\nRa, Dec 251.340   44.838 which is:\n\n    RA(J2000) = 16h 45m 21.7s\n    Dec(J2000) = +44d 50' 18.1\"\n\nThe light curve shows multiple peaks in WT and a power-law decay in PC  \nwith a\ndecay index of alpha=1.1(+/-0.2).\n\nA spectrum formed from the WT mode data can be fitted with an absorbed\npower-law with a photon spectral index of 1.84 (+/-0.02). The\nbest-fitting absorption column is 1.09 (+/-0.02) x 10^21 cm^-2, in\nexcess of the Galactic value of 1.3 x 10^20 cm^-2 (Kalberla et al.\n2005). The PC mode spectrum has a photon index of 2.3 (+/-0.3) and a\nbest-fitting absorption column of 1.4 (+/-0.1) x 10^21 cm^-2. The\ncounts to observed (unabsorbed) 0.3-10 keV flux conversion factor\ndeduced from this spectrum is 3.8 x 10^-11 (5.8 x 10^-11) erg cm^-2\ncount^-1.\n\nIf the light curve continues to decay with a power-law decay index of\n1.1, the count rate at T+24 hours will be 0.02 count s^-1,\ncorresponding to an observed (unabsorbed) 0.3-10 keV flux of 7.6 x\n10^-13 (1.2 x 10^-12) erg cm^-2 s^-1.\n\nThis circular is an official product of the Swift-XRT team.",
  "circularId": 9674,
  "createdOn": 1247723140000,
  "email": "vetere@astro.psu.edu",
  "subject": "GRB 090715B: Swift XRT Refined Analysis",
  "submitter": "Loredana Vetere at PSU  <vetere@astro.psu.edu>",
  "eventId": "GRB 090715B"
}