{
  "bibcode": "2012GCN.13405....1S",
  "body": "T. Sakamoto (GSFC/UMBC), S. D. Barthelmy (GSFC), Gehrels (GSFC),\nE. Sonbaas (GSFC)   (for the Swift-BAT team);\nO. Littlejohns (U. Leicester)  (for the Swift-XRT team);\nS. R. Oates (MSSL-UCL) (of the Swift-UVOT team):\n \nUsing the data set from T-60 to T+243 sec from recent telemetry downlinks,\nwe report further analysis of BAT GRB 120630A (trigger #525451).\nThere was no initial set of GCN Notices nor a rapid-response circular\nbecause of the power outage at GSFC when this burst occurred.\nSwift slewed immediately to the burst location.\n\nThe BAT ground-calculated position is RA, Dec = 352.300, 42.495 deg, which is \n   RA(J2000)  =  23h 29m 12.0s \n   Dec(J2000) = +42d 29' 41.5\" \nwith an uncertainty of 2.7 arcmin, (radius, sys+stat, 90% containment).\nThe partial coding was 65%.\n \nThe mask-weighted light curve shows a single spike starting at ~T-0.05 sec\nand ending at ~T+0.65 sec.  T90 (15-350 keV) is 0.6 +- 0.2 sec\n(estimated error including systematics).\n \nThe time-averaged spectrum from T-0.1 to T+0.6 sec is best fit by a simple\npower-law model.  The power law index of the time-averaged spectrum is\n1.04 +- 0.43.  The fluence in the 15-150 keV band is 6.1 +- 1.4 x 10^-8 erg/cm2.\nThe 1-sec peak photon flux measured from T-0.25 sec in the 15-150 keV band\nis 0.7 +- 0.2 ph/cm2/sec.  All the quoted errors are at the 90% confidence level. \n\nGiven the short duration and the hard spectrum of this burst,\nit is very likely a short GRB.\n \nThe results of the batgrbproduct analysis are available at\nhttp://gcn.gsfc.nasa.gov/notices_s/525451/BA/ .\n\n\nWe have analysed 1.4 ks of XRT data for GRB 120630A from 97 s to 1.5 ks\nafter the BAT trigger.  The data are entirely in Photon Counting (PC) mode.\nThe refined XRT position is RA, Dec = 352.29481, 42.55483 which is equivalent to:\n   RA (J2000): 23 29 10.75\n   Dec(J2000): +42 33 17.4\nwith an uncertainty of 3.9 arcsec (radius, 90% confidence).\n\nThe light curve can be modelled with a power-law decay with a decay index\nof alpha=1.7 (+/-0.5).\n\nA spectrum formed from the PC mode data can be fitted with an absorbed power-law\nwith a photon spectral index of 1.7 (+/-0.4).  The best-fitting absorption column\nis consistent with the Galactic value of 8.8 x 10^20 cm^-2 (Kalberla et al. 2005).\nThe counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced\nfrom this spectrum is 4.2 x 10^-11 (4.9 x 10^-11) erg cm^-2 count^-1.\n\nA summary of the PC-mode spectrum is thus:\n   Total column:        0 (+2.2, -0) x 10^21 cm^-2\n   Galactic foreground: 8.8 x 10^20 cm^-2\n   Excess significance: <1.6 sigma\n   Photon index:        1.7 (+/-0.4)\n\nThe results of the XRT-team automatic analysis are available at\nhttp://www.swift.ac.uk/xrt_products/00525451 .\n\n\nThe Swift/UVOT began settled observations of the field of GRB 120630A\n150 s after the BAT trigger (trigger #525451).  No optical afterglow\nconsistent with the refined XRT position nor with the candidate optical\nafterglow (Xu et al., GCN Circ. 13403) is detected in the initial UVOT\nexposures.  Preliminary 3-sigma upper limits using the UVOT photometric\nsystem (Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first\nfinding chart (FC) exposure and subsequent exposures are:\n\nFilter         T_start(s)   T_stop(s)      Exp(s)         Mag\nv                  457          1409         117         >19.0\nb                  406          1508         156         >20.0\nu_FC               150          400          246         >20.2\nu                  150          1032         393         >20.3\nuvw1               506          1458         117         >19.3\nuvm2               481          1434          97         >19.0\nuvw2               432          1530         131         >19.5\n\nThe magnitudes in the table are not corrected for the Galactic extinction\ndue to the reddening of E(B-V) = 0.106 in the direction of the burst\n(Schlegel et al. 1998).",
  "circularId": 13405,
  "createdOn": 1341315149000,
  "email": "scott@lheamail.gsfc.nasa.gov",
  "subject": "GRB 120630A: Swift-BAT/-XRT/-UVOT refined analysis",
  "submitter": "Scott Barthelmy at NASA/GSFC  <scott@lheamail.gsfc.nasa.gov>",
  "eventId": "GRB 120630A"
}