{
  "bibcode": "2003GCN..2478....1C",
  "body": "GRB031203: ROSAT upper limits suggest XMM-S1 source as the transient\n\nS. Campana, G. Tagliaferri, G. Chincarini, S. Covino, \nD. Fugazza (INAF-OAB), L. Stella (INAF-OAR)\n\nWe analysed ROSAT PSPC archival data of Zeta Puppis \n(rp200663n00, on-time 55 ks).\nThe two XMM-Newton sources (Santos-Lleo & Calderon \nGCN #2464) found in the INTEGRAL error box of GRB 031203 \nare within the inner rib of the PSPC.\nROSAT did not detect the two sources.\n\nUsing XIMAGE/sosta (and correcting for the exposure map), \nwe obtained a 3 sigma upper limit of \n 1.3E-03 c/s on S1 and of  \n 1.1E-03 c/s on S2.\nThe column density of this field is 6x1021 cm-2.\nAssuming a power law spectrum with photon index between \n1-2, we can extrapolate (using PIMMS) XMM-Newton rates of \n1.9E-02 - 3.5E-02 c/s for S1 and \n1.5E-02 - 2.9E-02 c/s for S2.\n\nThe XMM-Newton sources have been estimated to have a rate of:\nS1  0.10+/-0.015 c/s (error at 3 sigma)\nS2  0.04+/-0.010 c/s (error at 3 sigma).\n\nIf our assumptions on the spectrum are correct, \nwe note that the XMM-Newton count rate of S1 is \nnot compatible with the ROSAT PSPC upper limit,\nsuggesting that S1 is an X-ray variable source.",
  "circularId": 2478,
  "createdOn": 1070722115000,
  "email": "taglia@merate.mi.astro.it",
  "subject": "GRB031203: ROSAT upper limits suggest XMM-S1 source as the transient",
  "submitter": "Gianpiero Tagliaferri at OAB-INAF  <taglia@merate.mi.astro.it>",
  "eventId": "GRB 031203"
}