{
  "bibcode": "2008GCN..7882....1G",
  "body": "C. Guidorzi (INAF-OAB) and C. B. Markwardt (CRESST/GSFC/UMD) report\non behalf of the Swift-XRT team:\n\nThe Swift XRT began observing the INTEGRAL GRB 080613A\n(Gotz et al., GCN Circ 7871) on June 13, 16:19 UT, 24.2 ks after\nthe INTEGRAL trigger. The data consist of 3.6 ks observed in Photon \nCounting\nmode.\n\nWe detect a single X-ray source within the INTEGRAL error circle at the \nposition\nRA, Dec = 213.27213, +5.17256 which is equivalent to:\n\nRA (J2000):  14 13 05.31\nDec (J2000): +05 10 21.2\n\nwith an uncertainty of 5.2 arcsec (radius, 90% confidence).\nThis position lies 4.9\" from the optical afterglow found with the \nFaulkes Telescope North\n(Guidorzi et al., GCN Circ. 7872) and later confirmed by GROND (Clemens \net al. GCN Circ. 7880)\nand Swift-UVOT (Hoversten and Holland, GCN Circ. 7881), and is\ntherefore consistent with being the X-ray afterglow of GRB 080613A.\n\nPresently there is marginal evidence for fading: a power-law fit of the \nlight curve\ngives a decay index of 1.2 � 1.5, so still compatible with a constant \nrate of\nof (2.8 � 0.3)e-2 counts/s.\n\nForced by the small number of counts, we extracted the 0.3-10 keV spectrum\nfrom a 10-pixel radius circular region and adopted the Cash statistics.\nThe spectrum can be fit with a power law with an absorbing column\ndensity fixed to the Galactic value (2.0e20 cm-2) and a photon index of\n1.3 � 0.3. The observed (unabsorbed) 0.3-10 keV flux\nis 1.50 (1.53)e-12 erg cm-2 s-1.\n\nThis circular is an official product of the Swift-XRT team.",
  "circularId": 7882,
  "createdOn": 1213434927000,
  "email": "cristiano.guidorzi@brera.inaf.it",
  "subject": "GRB 080613A: Swift-XRT detection of the afterglow",
  "submitter": "Cristiano Guidorzi at INAF-OAB  <cristiano.guidorzi@brera.inaf.it>",
  "eventId": "GRB 080613A"
}