{
  "bibcode": "2017GCN.22027....1R",
  "body": "O.J. Roberts (USRA), R. Hamburg (UAH), M.S. Briggs (UAH), \nV. Connaughton (USRA), C. Kouveliotou (GWU) and G. Younes (GWU) \nreport on behalf of the Fermi-GBM Team:\n\n\"At 01:01:16.25 UT on 19 October 2017, the Fermi Gamma-Ray \nBurst Monitor triggered (trigger 530067681 / 171019043) \non a bright SGR-like burst. The GBM on-ground location is \nconsistent with the position of the known source \nAXP CXOU J164710.2-455216/PSR J1647-4552, which later \ntriggered Swift-BAT (Beardmore et al., GCN 22024 and \nLien et al., GCN 22025). MAXI also triggered on a \ntransient from a position consistent with the source.\n\nThe GBM light curve shows two bright, short peaks each with\na duration (T90) of about 0.1 s. The time-averaged spectrum\nover both peaks from T0-0.064 to T0+0.384 is best fit by a \npower-law function with an exponential high-energy cutoff.  \nThe power law index is 0.04 +/- 0.13 and the cutoff energy, \nparameterized as Epeak, is 35 +/- 1 keV.\n\nThe event fluence (10-1000 keV) in this time interval is\n(7.4 +/- 0.12)E-07 erg/cm^2. The photon flux measured starting\nfrom T0-0.64 s in the 10-1000 keV band is 37 +/- 1 ph/s/cm^2.\n\nAn offline search of the GBM time-tagged event data optimized\nto find sub-threshold short GRBs uncovered at least one\nadditional burst that could have come from this source.  \nThis is consistent with the ongoing source activity reported\nby Lien et al. (GCN 22025). The offline search results are\ndistributed as GCN notices \n(https://gcn.gsfc.nasa.gov/admin/fermi_gbm_subthreshold_announce.txt)\nwith the notice archive available at \nhttps://gcn.gsfc.nasa.gov/fermi_gbm_subthresh_archive.html.\nThe results of a dedicated search for magnetar bursts will be \npresented in a future circular.\"",
  "circularId": 22027,
  "createdOn": 1508439105000,
  "email": "oliver.roberts@nasa.gov",
  "subject": "Fermi-GBM Detection of possible burst from AXP CXOU J164710.2-455216/PSR J1647-4552",
  "submitter": "Oliver J Roberts at USRA/NASA  <oliver.roberts@nasa.gov>"
}