{
  "bibcode": "2018GCN.23032....1D",
  "body": "P. D'Avanzo (INAF-OAB), V. D'Elia (ASDC), B. Sbarufatti (INAF-OAB/PSU),\nD.N. Burrows (PSU), A. Tohuvavohu (PSU), S.L. Gibson (U. Leicester), Z.\nLiu (NAOC / U. Leicester), J.P. Osborne (U. Leicester), A. D'Ai\n(INAF-IASFPA) and P.A. Evans (U. Leicester) report on behalf of the\nSwift-XRT team:\n\nSwift-XRT has performed follow-up observations of the MAXI-detected\nburst GRB 180722A (Shimomukai et al. GCN Circ. 23005) in a series of\nobservations tiled on the sky. The total exposure time is 1.2 ks,\ndistributed over 7 tiles; the maximum exposure at a single sky location\nwas 391 s. The data were collected between T0+45.7 ks and T0+47.1 ks,\nand are entirely in Photon Counting (PC) mode. \n\nNo X-ray sources have been detected. The 3-sigma upper limit in the\nfield (not including the regions where the tiles overlap) ranges from\n~0.04 to ~0.12 ct s^-1, corresponding to a 0.3-10 keV observed flux of\n1.8e-12 to 4.9e-12 erg cm^-2 s^-1 (assuming a typical GRB spectrum).\n\nThe results of the XRT-team automatic analysis of the tiled XRT\nobservations, including a position-specific upper limit calculator, are\navailable at http://www.swift.ac.uk/xrt_products/TILED_GRB00071.\n\nThis circular is an official product of the Swift-XRT team.",
  "circularId": 23032,
  "createdOn": 1532442825000,
  "email": "bxs60@psu.edu",
  "subject": "GRB 180722A: Swift-XRT observations",
  "submitter": "Boris Sbarufatti at PSU  <bxs60@psu.edu>",
  "eventId": "GRB 180722A"
}