batgrbproduct Analysis for Trigger=278854
Analysis Summary
Notes:
- 1) No attempt has been made to eliminate the non-significant decimal places.
- 2) This batgrbproduct analysis is done of the amount of data for this trigger downloaded to date.
- 3) This page will be updated for up to 8 downlinks after the trigger.
======================================================================
BAT GRB EVENT DATA PROCESSING REPORT
Process Script Ver: batgrbproduct v2.41
Process Start Time (local time): Thu Dec 13 20:50:44 EST 2007
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger278854/GCN5_download_cron
======================================================================
Trigger: 00278854 Segment: 000
BAT Trigger Time: 200290699.776 [s; MET]
Trigger Stop: 200290700.8 [s; MET]
UTC: 2007-05-08T04:18:17.835440 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 312.782826014256 Dec: -78.3681172291522 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 19.9
Image Trigger?: NO
Rate S/N Ratio: 51.0392006206994 [ if not an image trigger ]
Image S/N Ratio: 19.9
Flight Position: [ source = BAT ]
RA: 312.782826014256 Dec: -78.3681172291522 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 312.812556260862 Dec: -78.3824937227455 [deg; J2000]
{ 20h 51m 15.0s , -78d 22' 57.0" }
+/- 0.443146370945953 [arcmin] (estimated 90% radius based on SNR)
+/- 0.133011580077086 [arcmin] (formal 1-sigma fit error)
SNR: 97.2861362453434
RA = 20h 51m 15.0s (312.812556 deg.)
Dec = -78d 22' 57" (-78.382494 deg.)
Angular difference between Flight and Ground position is 0.934482 arcmin
Partial Coding Fraction: 0.625 [ including projection effects ]
Duration
T90: 20.863999992609 +/- 0.735923905696808
Measured from: -0.359999984502792
to: 20.5040000081062 [s; relative to TRIGTIME]
T50: 7.59999999403954 +/- 0.147186979664657
Measured from: 5.96400001645088
to: 13.5640000104904 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 10.8440000116825
to: 11.8440000116825 [s; relative to TRIGTIME]
Total Fluence
Measured from: -13.755999982357
to: 33.1120000183582 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 7.066438 10.442918 8.993306 2.248471
0.059705 0.064413 0.060488 0.041987 [error]
Peak 0.560191 1.057723 1.091251 0.290749
0.013366 0.017201 0.018123 0.011362 [error]
[ fluence units of on-axis counts / fully illuminated detector ]
======================================================================
=== Fluence/Peak Flux Summary ===
Model Band1 Band2 Band3 Band4 Band5 Total
15-25 25-50 50-100 100-350 15-150 15-350 keV
Fluence Power-law 2.26e-06 4.54e-06 7.09e-06 2.44e-05 1.98e-05 3.72e-05 erg/cm2
Error 7.66e-08 8.98e-08 9.59e-08 8.25e-07 2.58e-07 0.00e+00 erg/cm2
Peak flux Power-law 5.93e+00 7.62e+00 7.15e+00 1.18e+01 2.47e+01 3.25e+01 ph/cm2/s
Error 2.89e-01 2.23e-01 1.59e-01 5.90e-01 5.76e-01 7.06e-01 ph/cm2/s
Fluence Cutoff-PL 2.09e-06 4.52e-06 7.27e-06 1.98e-05 1.96e-05 2.54e-05 erg/cm2
Error 1.15e-07 9.18e-08 1.32e-07 2.16e-06 2.73e-07 0.00e+00 erg/cm2
Peak flux Cutoff-PL 5.09e+00 7.63e+00 7.58e+00 8.35e+00 2.41e+01 2.86e+01 ph/cm2/s
Error 4.03e-01 2.33e-01 2.25e-01 1.08e+00 6.13e-01 1.30e+00 ph/cm2/s
Fluence Band 2.07e-06 4.51e-06 7.26e-06 1.98e-05 1.96e-05 2.64e-05 erg/cm2
Error 1.14e-07 9.17e-08 1.31e-07 2.17e-06 2.73e-07 0.00e+00 erg/cm2
Peak flux Band 5.09e+00 7.63e+00 7.58e+00 8.35e+00 2.41e+01 2.86e+01 ph/cm2/s
Error 4.03e-01 2.33e-01 2.25e-01 1.08e+00 6.13e-01 1.65e+00 ph/cm2/s
=== Time-averaged spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.356 0.027 - - 4.33e-02 6.26e-04 38.387 57
CPL 1.138 0.117 260.4 134.3 5.22e-02 5.21e-03 27.734 56
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.091 0.040 - - 2.13e-01 4.69e-03 74.350 57
CPL 0.636 0.178 189.7 56.4 3.24e-01 5.22e-02 53.546 56
Model : spectral model: simple power-law (PL) and cutoff power-law (CPL)
Ph_index : photon index: E^-{Ph_index} (minus sign is not included in the index)
Ph_90err : 90% error of the photon index
Epeak : Epeak in keV
Epeak_90err: 90% error of Epeak
Norm : normalization at 50 keV in PL model and at 1 keV in CPL model
Nomr_90err : 90% error of the normalization
chi2 : Chi-Squared
dof : degree of freedom
=== T90/T50 calculation in the 50-300 keV band (BATSE band) using 64 ms lc ===
T90 in the 50-300 keV band: 17.088000 sec.
T50 in the 50-300 keV band: 6.784000 sec.
=== Table of the duration information ==
Value tstart tstop
T100 46.868 -13.756 33.112
T90 20.864 -0.360 20.504
T50 7.600 5.964 13.564
Peak 1.000 10.844 11.844
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
312.8126 -78.3825 0.0019 28.3 -126.9 19.1870 97.3 TRIG_00278854
------------------------------------------
Foreground time interval of the image:
-13.756 12.325 (delta_t = 26.081 [sec])
Background time interval of the image:
-239.776 -54.360 (delta_t = 185.416 [sec])
-53.776 -13.756 (delta_t = 40.020 [sec])
Lightcurves
Notes:
- 1) All plots contain as much data as has been downloaded to date.
- 2) Multiple plots of different time binning/intervals are shown to cover all scenarios of short/long GRBs, rate/image triggers, and real/false positives.
- 3) For all the mask-weighted lightcurves, the y-axis units are counts/sec/det where a det is 0.4 x 0.4 = 0.16 sq cm.
- 4) The verticle lines correspond to following: green dotted lines are T50 interval, black dotted lines are T90 interval, blue solid line(s) is a spacecraft slew start time, and orange solid line(s) is a spacecraft slew end time.
- 5) Time of each bin is in the middle of the bin.
1 s binning
From T0-310 s to T0+310 s
From T100_start - 20 s to T100_end + 30 s
Full time interval
64 ms binning
Full time interval
From T100_start to T100_end
From T0-5 sec to T0+5 sec
16 ms binning
From T100_start-5 s to T100_start+5 s
8 ms binning
From T100_start-3 s to T100_start+3 s
2 ms binning
From T100_start-1 s to T100_start+1 s
SN=5 or 10 sec. binning (whichever binning is satisfied first)
SN=5 or 10 sec. binning (T < 200 sec)
Spectra
Notes:
- 1) The fitting includes the systematic errors.
- 2) For long bursts, a spectral fit of the pre-slew DRM will introduce some errors in both a spectral shape and a normalization if the PHA file contains a lot of the slew/post-slew time interval.
- 3) For fits to more complicated models (e.g. a power-law over a cutoff power-law), the BAT team has decided to require a chi-square improvement of more than 6 for each extra dof.
Time averaged spectrum fit using the pre-slew DRM
Power-law model
Time interval is from -13.756 sec. to 33.112 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.35586 ( -2.672839E-02 2.663827E-02) )
Norm@50keV : 4.325451E-02 ( -6.269515E-04 6.255135E-04) )
------------------------------------------------------------
Chi-Squared = 38.38741 using 59 PHA bins.
Reduced chi-squared = 0.6734634 for 57 degrees of freedom
Null hypothesis probability = 0.972
Photon flux (15-150 keV) in 46.87 sec: 5.21725 ( -0.09171 0.0922 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.97745e-05 ( -2.57551e-07 2.57832e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -13.756 sec. to 33.112 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.13819 ( -0.121131 0.113186 )
Epeak [keV] : 260.428 ( -69.1248 199.555 )
Norm@50keV : 5.220703E-02 ( -4.773293E-03 5.637411E-03) )
------------------------------------------------------------
Chi-Squared = 27.73422 using 59 PHA bins.
Reduced chi-squared = 0.4952540 for 56 degrees of freedom
Null hypothesis probability = 0.999
Photon flux (15-150 keV) in 46.87 sec: 5.09552 ( -0.10768 0.10939 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.96103e-05 ( -2.73111e-07 2.72877e-07 ) ergs/cm2
Band function
Time interval is from -13.756 sec. to 33.112 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.13572 ( -0.115556 0.118647 )
beta : -9.25624 ( -0.743759 7.80247 )
Epeak [keV] : 258.141 ( -66.8699 201.751 )
Norm@50keV : 5.231531E-02 ( -4.886542E-03 5.523667E-03) )
------------------------------------------------------------
Chi-Squared = 27.73352 using 59 PHA bins.
Reduced chi-squared = 0.5042458 for 55 degrees of freedom
Null hypothesis probability = 0.999
Photon flux (15-150 keV) in 46.87 sec: 5.09568 ( -0.10822 0.10942 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.95948e-05 ( -2.72924e-07 2.72596e-07 ) ergs/cm2
Peak spectrum fit using the pre-slew DRM
Power-law model
Time interval is from 10.844 sec. to 11.844 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.09100 ( -3.959405E-02 3.946722E-02) )
Norm@50keV : 0.212963 ( -4.693642E-03 4.685253E-03) )
------------------------------------------------------------
Chi-Squared = 74.34999 using 59 PHA bins.
Reduced chi-squared = 1.304386 for 57 degrees of freedom
Null hypothesis probability = 6.113E-02
Photon flux (15-150 keV) in 1.000 sec: 24.6811 ( -0.5754 0.5773 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.23302e-06 ( -4.9014e-08 4.9047e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 10.844 sec. to 11.844 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.635909 ( -0.181992 0.174649 )
Epeak [keV] : 189.704 ( -36.3292 76.4199 )
Norm@50keV : 0.323780 ( -4.707474E-02 5.726719E-02) )
------------------------------------------------------------
Chi-Squared = 53.54583 using 59 PHA bins.
Reduced chi-squared = 0.9561754 for 56 degrees of freedom
Null hypothesis probability = 0.568
Photon flux (15-150 keV) in 1.000 sec: 24.0561 ( -0.6111 0.614 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.2117e-06 ( -5.0831e-08 5.0586e-08 ) ergs/cm2
Band function
Time interval is from 10.844 sec. to 11.844 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.635845 ( -0.174695 0.181965 )
beta : -9.30690 ( -0.693101 7.96314 )
Epeak [keV] : 189.670 ( -36.3089 76.4081 )
Norm@50keV : 0.323781 ( -4.708898E-02 5.727583E-02) )
------------------------------------------------------------
Chi-Squared = 53.54624 using 59 PHA bins.
Reduced chi-squared = 0.9735680 for 55 degrees of freedom
Null hypothesis probability = 0.530
Photon flux (15-150 keV) in 1.000 sec: 24.0568 ( -0.6118 0.6136 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.21034e-06 ( -5.078e-08 5.0568e-08 ) ergs/cm2
Plot creation:
Thu Dec 13 21:06:36 EST 2007