{
  "bibcode": "2020GCN.27384....1S",
  "body": "M. Stamatikos (OSU), S. D. Barthelmy (GSFC), J. R. Cummings (CPI),\nP. A. Evans (U Leicester), H. A. Krimm (NSF),S. Laha (GSFC/UMBC),\nA. Y. Lien (GSFC/UMBC), C. B. Markwardt (GSFC), D. M. Palmer (LANL),\nT. Sakamoto (AGU), T. N. Ukwatta (LANL)\n(i.e. the Swift-BAT team):\n  \nUsing the data set from T-61 to T+242 sec from the recent telemetry downlink,\nwe report further analysis of the BAT detection of a burst from a newly\ndiscovered SGR Swift J1818.0-1607 (trigger #960986)\n(Evans, et al., GCN Circ. 27373).  The BAT ground-calculated position is\nRA, Dec = 274.515, -16.125 deg which is\n    RA(J2000)  =  18h 18m 03.7s\n    Dec(J2000) = -16d 07' 31.8\"\nwith an uncertainty of 2.7 arcmin, (radius, sys+stat, 90% containment).\nThe partial coding was 99%.\n  \nThe mask-weighted light curve in 2 ms time bins shows a burst that starts\nat T-0.005 sec, peaks at T+0.002 sec and ends at T+0.015 sec.  There is a hint\nof a second pulse around T+0.01 s.  T90 (15-350 keV) is ~0.01 sec.\n  \nThe time-averaged spectrum from T+0.00 to T+0.01 sec fit by a simple\npower-law model shows the power law index of 3.17 +- 0.63\n(chi squared 51.9 for 57 d.o.f.).  The fluence in the 15-150 keV band is\n2.9 +- 1.1 x 10^-9 erg/cm2.  The 1-sec peak photon flux measured from\nT+0.00 sec in the 15-150 keV band is 8.7 +- 3.1 ph/cm2/sec.\n\nA single blackbody fit to the time-averaged spectrum shows the blackbody\ntemperature of 5.5 +- 0.9 keV (chi squared 43.2 for 57 d.o.f.).  A thermal\nbremsstrahlung model fit shows the temperature of 15.8 +- 6.5 keV\n(chi squared 48.7 for 57 d.o.f.).  All the quoted errors are at the 90%\nconfidence level.\n  \nThe results of the batgrbproduct analysis are available at\nhttp://gcn.gsfc.nasa.gov/notices_s/960986/BA/",
  "circularId": 27384,
  "createdOn": 1584164449000,
  "email": "tsakamoto@phys.aoyama.ac.jp",
  "subject": "SGR Swift J1818.0-1607: Swift-BAT refined analysis",
  "submitter": "Takanori Sakamoto at AGU  <tsakamoto@phys.aoyama.ac.jp>"
}