batgrbproduct Analysis for Trigger=283791
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): Fri Dec 14 03:30:26 EST 2007
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger283791/GCN5_download_cron
======================================================================
Trigger: 00283791 Segment: 000
BAT Trigger Time: 205272360 [s; MET]
Trigger Stop: 205272424 [s; MET]
UTC: 2007-07-04T20:05:57.934440 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 354.72344217874 Dec: 66.2478751765386 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 16.12
Image Trigger?: YES
Rate S/N Ratio: 0 [ if not an image trigger ]
Image S/N Ratio: 16.12
Flight Position: [ source = BAT ]
RA: 354.72344217874 Dec: 66.2478751765386 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 354.705440299763 Dec: 66.2573633778711 [deg; J2000]
{ 23h 38m 49.3s , +66d 15' 26.5" }
+/- 1.61764025135931 [arcmin] (estimated 90% radius based on SNR)
+/- 0.834303596855121 [arcmin] (formal 1-sigma fit error)
SNR: 15.3008515516708
RA = 23h 38m 49.3s (354.705440 deg.)
Dec = 66d 15' 27" (66.257363 deg.)
Angular difference between Flight and Ground position is 0.716442 arcmin
Partial Coding Fraction: 0.4257812 [ including projection effects ]
Duration
T90: 384.204000025988 +/- 24.5347665138576
Measured from: -53.7520000040531
to: 330.452000021935 [s; relative to TRIGTIME]
T50: 66.6599999964237 +/- 14.9316678251548
Measured from: -39.1119999885559
to: 27.5480000078678 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: -53.0999999940395
to: -52.0999999940395 [s; relative to TRIGTIME]
Total Fluence
Measured from: -57.3160000145435
to: 400.775999993086 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 2.979430 3.649257 2.484701 0.582572
0.121099 0.122232 0.106994 0.091096 [error]
Peak 0.043800 0.088660 0.095527 0.026401
0.005222 0.005920 0.005703 0.004219 [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 1.08e-06 1.67e-06 1.93e-06 4.31e-06 5.95e-06 8.99e-06 erg/cm2
Error 8.40e-08 7.48e-08 1.07e-07 5.32e-07 2.56e-07 6.00e-07 erg/cm2
Peak flux Power-law 5.28e-01 6.65e-01 6.10e-01 9.77e-01 2.14e+00 2.78e+00 ph/cm2/s
Error 7.35e-02 5.73e-02 4.29e-02 1.44e-01 1.53e-01 1.89e-01 ph/cm2/s
Fluence Cutoff-PL 1.04e-06 1.69e-06 1.96e-06 3.38e-06 5.88e-06 8.03e-06 erg/cm2
Error 1.07e-07 8.43e-08 1.17e-07 1.23e-06 2.08e-07 1.27e-06 erg/cm2
Peak flux Cutoff-PL 4.34e-01 6.90e-01 6.72e-01 5.50e-01 2.09e+00 2.35e+00 ph/cm2/s
Error 9.42e-02 6.40e-02 6.17e-02 2.26e-01 1.57e-01 2.73e-01 ph/cm2/s
Fluence Band 1.07e-06 1.66e-06 1.92e-06 4.21e-06 5.92e-06 8.96e-06 erg/cm2
Error 6.57e-08 7.94e-08 6.98e-08 5.02e-07 2.49e-07 4.77e-07 erg/cm2
Peak flux Band 4.04e-01 7.07e-01 6.61e-01 7.41e-01 2.07e+00 2.52e+00 ph/cm2/s
Error 1.11e-01 7.25e-02 6.07e-02 2.68e-01 1.60e-01 2.91e-01 ph/cm2/s
=== Time-averaged spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.786 0.080 - - 1.41e-03 5.95e-05 53.393 57
CPL 1.522 0.293 94.8 0.0 1.88e-03 5.44e-04 52.692 56
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.124 0.113 - - 1.84e-02 1.25e-03 51.737 57
CPL 0.403 0.558 130.8 104.3 3.80e-02 2.26e-02 45.942 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: 64.192000 sec.
T50 in the 50-300 keV band: 25.856000 sec.
=== Table of the duration information ==
Value tstart tstop
T100 458.092 -57.316 400.776
T90 384.204 -53.752 330.452
T50 66.660 -39.112 27.548
Peak 1.000 -53.100 -52.100
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
354.7054 +66.2574 0.0126 42.5 174.4 2.1422 15.3 TRIG_00283791
------------------------------------------
Foreground time interval of the image:
-2.699 70.101 (delta_t = 72.800 [sec])
Background time interval of the image:
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 -57.316 sec. to 400.776 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.78609 ( -7.933831E-02 7.994759E-02) )
Norm@50keV : 1.409938E-03 ( -5.962455E-05 5.940767E-05) )
------------------------------------------------------------
Chi-Squared = 53.39332 using 59 PHA bins.
Reduced chi-squared = 0.9367249 for 57 degrees of freedom
Null hypothesis probability = 0.611
Photon flux (15-150 keV) in 458.1 sec: 0.193249 ( -0.008954 0.009 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.94925e-06 ( -2.55482e-07 2.56444e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -57.316 sec. to 400.776 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.52160 ( -0.253029 0.332626 )
Epeak [keV] : 94.8057 ( )
Norm@50keV : 1.878825E-03 ( -2.545593E-04 8.344364E-04) )
------------------------------------------------------------
Chi-Squared = 52.69191 using 59 PHA bins.
Reduced chi-squared = 0.9409270 for 56 degrees of freedom
Null hypothesis probability = 0.601
Photon flux (15-150 keV) in 458.1 sec: 0.190769 ( -0.0098 0.004917 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.88448e-06 ( -1.41278e-07 2.75685e-07 ) ergs/cm2
Band function
Time interval is from -57.316 sec. to 400.776 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.40017 ( -8.59983 4.07369 )
beta : -1.81286 ( -7.72817 0.550744 )
Epeak [keV] : 51.8932 ( -101.835 9898.06 )
Norm@50keV : 2.464929E-03 ( -3.556384E-04 327.238 )
------------------------------------------------------------
Chi-Squared = 53.08123 using 59 PHA bins.
Reduced chi-squared = 0.9651133 for 55 degrees of freedom
Null hypothesis probability = 0.548
Photon flux (15-150 keV) in 458.1 sec: 0.190772 ( -0.009843 0.009878 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.92484e-06 ( -2.53971e-07 2.44396e-07 ) ergs/cm2
Peak spectrum fit using the pre-slew DRM
Power-law model
Time interval is from -53.100 sec. to -52.100 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.12440 ( -0.113931 0.111966 )
Norm@50keV : 1.836851E-02 ( -1.253977E-03 1.249703E-03) )
------------------------------------------------------------
Chi-Squared = 51.73697 using 59 PHA bins.
Reduced chi-squared = 0.9076661 for 57 degrees of freedom
Null hypothesis probability = 0.672
Photon flux (15-150 keV) in 1.000 sec: 2.13592 ( -0.15318 0.15366 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.90595e-07 ( -1.319e-08 1.3201e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -53.100 sec. to -52.100 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.402834 ( -0.596898 0.519377 )
Epeak [keV] : 130.809 ( -34.4817 174.066 )
Norm@50keV : 3.799242E-02 ( -1.526300E-02 2.998012E-02) )
------------------------------------------------------------
Chi-Squared = 45.94166 using 59 PHA bins.
Reduced chi-squared = 0.8203868 for 56 degrees of freedom
Null hypothesis probability = 0.829
Photon flux (15-150 keV) in 1.000 sec: 2.08939 ( -0.15629 0.15681 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.88036e-07 ( -1.3865e-08 1.3652e-08 ) ergs/cm2
Band function
Time interval is from -53.100 sec. to -52.100 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : 0.182878 ( -0.941548 1.75830 )
beta : -1.51231 ( -8.48769 0.280950 )
Epeak [keV] : 84.7022 ( -29.5842 115.816 )
Norm@50keV : 7.825876E-02 ( -7.825876E-02 0.630717 )
------------------------------------------------------------
Chi-Squared = 44.47772 using 59 PHA bins.
Reduced chi-squared = 0.8086858 for 55 degrees of freedom
Null hypothesis probability = 0.844
Photon flux (15-150 keV) in 1.000 sec: 2.06565 ( -0.16457 0.1548 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.87888e-07 ( -1.3816e-08 1.3677e-08 ) ergs/cm2
Plot creation:
Fri Dec 14 03:52:32 EST 2007