{
  "bibcode": "2011GCN.12359....1B",
  "body": "W. H. Baumgartner (GSFC/UMBC), D. N. Burrows (PSU),\nJ. R. Cummings (NASA/UMBC), N. Gehrels (NASA/GSFC), C. Gronwall (PSU),\nS. T. Holland (CRESST/USRA/GSFC), J. A. Kennea (PSU),\nV. Mangano (INAF-IASFPA), C. B. Markwardt (NASA/GSFC),\nF. E. Marshall (NASA/GSFC), J. L. Racusin (NASA/GSFC),\nB. Sbarufatti (INAF-OAB/IASFPA), E. Sonbas (GSFC/USRA/Adiyaman Univ.)\nand T. N. Ukwatta (MSU) report on behalf of the Swift Team:\n\nAt 21:16:11 UT, the Swift Burst Alert Telescope (BAT) triggered and\nlocated PSR J1647-4552 (trigger=503525).  Swift slewed immediately to the \nposition.  Approximately ten minutes later (21:25:44 UT), BAT triggered\nagain on same position (trigger=503526). The first BAT on-board calculated\nlocation is RA, Dec 251.752, -45.843 which is \n   RA(J2000) = 16h 47m 00s\n   Dec(J2000) = -45d 50' 33\"\nwith an uncertainty of 3 arcmin (radius, 90% containment, including \nsystematic uncertainty).  The BAT light curve of the first trigger\n(503525) showed a single-peaked structure with a duration of \nabout 0.25 sec.  The peak count rate was ~2500 counts/sec (15-350 keV),\nat ~0 sec after the trigger.  The second burst had a similar burst \nintensity and time profile. \n\nThe XRT began observing the field at 21:17:07.5 UT, 56.0 seconds after\nthe BAT trigger. Using promptly downlinked data we find an X-ray source\nlocated at RA, Dec 251.79387, -45.87095 which is equivalent to:\n   RA(J2000)  = 16h 47m 10.53s\n   Dec(J2000) = -45d 52' 15.4\"\nwith an uncertainty of 3.9 arcseconds (radius, 90% containment). This\nlocation is 145 arcseconds from the BAT onboard position, within the\nBAT error circle. This position may be improved as more data are\nreceived; the latest position is available at\nhttp://www.swift.ac.uk/sper. This position is 3.5 arcseconds from that\nof a known X-ray source: CXOU J164710.2-455216/PSR J1647-4552, a known \nmagnetar (e.g. Woods et al., 2011, ApJ, 726, 37). \n\nA power-law fit to a spectrum formed from promptly downlinked event\ndata gives a column density in excess of the Galactic value (1.88 x\n10^22 cm^-2, Kalberla et al. 2005), with an excess column of 2.5\n(+2.00/-1.60) x 10^22 cm^-2 (90% confidence). \n\nUVOT took a finding chart exposure of 150 seconds with the White filter\nstarting 60 seconds after the BAT trigger. No credible afterglow candidate has\nbeen found in the initial data products. The 2.7'x2.7' sub-image covers none of\nthe XRT error circle. The 8'x8' region for the list of sources generated\non-board covers 100% of the XRT error circle. No correction has been made for\nthe large, but uncertain extinction expected. \n\nIt appears that this PSR is entering an SGR-like phase of activity.",
  "circularId": 12359,
  "createdOn": 1316468340000,
  "email": "burrows@astro.psu.edu",
  "subject": "Swift detection of short bursts from PSR J1647-4552",
  "submitter": "David Burrows at PSU/Swift  <burrows@astro.psu.edu>"
}