{
  "bibcode": "2007GCN..6287....1R",
  "body": "P. Romano (Univ. Bicocca & INAF-OAB), A. Moretti (INAF-OAB),\nC. Guidorzi (Univ. Bicocca & INAF-OAB) report on behalf of the Swift Team:\n\nWe have analysed the first 4 orbits of XRT data from GRB 070412\n(trigger=275119; Romano et al., GCN Circ. 6273), which include\n40s in WT and 2.4ks in PC mode.\nThe refined XRT position is RA,Dec=181.5426 +40.1438:\nRA(J2000)  =12h 06m 10.2s\nDec(J2000) =+40d 08' 37.8\"\nwith an uncertainty of 4 arcsec (90% containment, see GCN Circ. 6282).\n\nThe 0.3-10 keV X-ray light curve can be fit with a simple power-law\nwith a decay slope of 0.98+/-0.05, although the initial descent could\nbe due to a flare or the tail of the prompt emission (slope of ~-3.5).\n\nThe X-ray spectrum from the XRT/WT data (40s starting from T+67.8) can be fit by an\nabsorbed power-law with a photon index\nof 2.2+/-0.5 and column density of (1.8-0.9+1.1)E21 cm**-2, higher than the Galactic\ncolumn density in the direction of the source\n(1.95E20 cm**-2). The unabsorbed (absorbed) 0.3-10 keV flux for this  spectrum is\n3.3E-10 (2.2E-10) erg/cm**2/s.\nThe XRT/PC data (2.4ks starting from T+3386) can be fit by an absorbed  power-law with a\nphoton index of 2.3-0.5+0.6 and column density of  (2.5-1.2+1.4)E21 cm**-2, consistently\nwith the WT data.\nThe unabsorbed (absorbed) 0.3-10 keV flux for this\nspectrum is 6.1E-12 (3.3E-12) erg/cm**2/s.\n\nAssuming the X-ray emission continues to decline at the same rate, we predict a 0.3-10\nkeV XRT count rate of 5.6E-3 count/s at T+24hr, which corresponds to an observed 0.3-10\nkeV flux of 2.8E-13 erg/cm**2/s.\n\nThis circular is an official product of the Swift XRT Team.",
  "circularId": 6287,
  "createdOn": 1176382216000,
  "email": "patrizia.romano@brera.inaf.it",
  "subject": "GRB 070412: Swift-XRT refined analysis",
  "submitter": "Pat Romano at OAB-Swift  <patrizia.romano@brera.inaf.it>",
  "eventId": "GRB 070412"
}