{
  "bibcode": "2008GCN..8286....1M",
  "body": "V. Mangano, B. Sbarufatti, V. La Parola (INAF-IASFPa), on behalf of the Swift-XRT team\n\nThe XRT started observing the field of the BAT  trigger 325707 \n(Immler et al.,  GCN Circ. 8285) on 2008-09-23, at 21:50:46UT, \n80.1s after the BAT trigger. \n\n   No X-ray source was found in or near the BAT error circle in a 3.3 ks\nexposure (17 ksec elapsed time) Swift/XRT Photon Counting mode image \ndown to a 3 sigma limiting 0.3-10keV count\nrate of 3.67e-3 count/s. Assuming a power-law spectrum of photon index 2\nabsorbed by the Galactic column density of 2.16e21 cm-2 at the position \nof the BAT trigger, this corresponds to an observed 0.3-10 keV flux limit of\n1.50e-13 erg cm-2 s-1.\n\nThis circular is an official product of the Swift-XRT team.",
  "circularId": 8286,
  "createdOn": 1222248440000,
  "email": "laparola@ifc.inaf.it",
  "subject": "Swift trigger 325707: Swift-XRT upper limit",
  "submitter": "Valentina La Parola at INAF-IASPA  <laparola@ifc.inaf.it>"
}