batgrbproduct Analysis for Trigger=338633
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 v2.42
Process Start Time (local time): Wed Dec 31 08:28:56 EST 2008
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger338633/SDC
======================================================================
Trigger: 00338633 Segment: 000
BAT Trigger Time: 252362176 [s; MET]
Trigger Stop: 252362240 [s; MET]
UTC: 2008-12-30T20:36:12.623340 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 37.3152367645834 Dec: -25.1417564760223 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 16.75
Image Trigger?: YES
Rate S/N Ratio: 0 [ if not an image trigger ]
Image S/N Ratio: 16.75
Flight Position: [ source = BAT ]
RA: 37.3152367645834 Dec: -25.1417564760223 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 37.3301424043743 Dec: -25.1451561354771 [deg; J2000]
{ 02h 29m 19.2s , -25d 08' 42.6" }
+/- 1.43667833522145 [arcmin] (estimated 90% radius based on SNR)
+/- 0.698896756261398 [arcmin] (formal 1-sigma fit error)
SNR: 18.1267119388016
Angular difference between Flight and Ground position is 0.834898 arcmin
Partial Coding Fraction: 1 [ including projection effects ]
Duration
T90: 60.7000000178814 +/- 13.7743084089789
Measured from: -0.904000014066696
to: 59.7960000038147 [s; relative to TRIGTIME]
T50: 21.4800000190735 +/- 4.04095237249567
Measured from: 31.1480000019073
to: 52.6280000209808 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 46.6279999911785
to: 47.6279999911785 [s; relative to TRIGTIME]
Total Fluence
Measured from: -14.4320000112057
to: 62.4280000030994 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.576104 0.610746 0.319140 0.020039
0.042160 0.042362 0.037386 0.032438 [error]
Peak 0.028143 0.029572 0.026538 0.005184
0.004993 0.005194 0.004425 0.003708 [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 1.77e-07 2.45e-07 2.50e-07 4.68e-07 8.21e-07 1.14e-06 erg/cm2
Error 2.13e-08 2.00e-08 3.59e-08 1.34e-07 8.12e-08 1.72e-07 erg/cm2
Peak flux Power-law 2.42e-01 2.40e-01 1.67e-01 1.83e-01 7.21e-01 8.31e-01 ph/cm2/s
Error 6.56e-02 4.09e-02 3.69e-02 8.22e-02 1.19e-01 1.41e-01 ph/cm2/s
Fluence Cutoff-PL 1.67e-07 2.60e-07 2.46e-07 1.96e-07 7.79e-07 8.79e-07 erg/cm2
Error 2.42e-08 2.65e-08 3.97e-08 1.55e-07 9.34e-08 2.73e-07 erg/cm2
Peak flux Cutoff-PL 2.39e-01 2.41e-01 1.68e-01 1.70e-01 7.19e-01 8.13e-01 ph/cm2/s
Error 7.10e-02 4.75e-02 3.91e-02 1.17e-01 1.21e-01 1.71e-01 ph/cm2/s
Fluence Band 1.66e-07 2.58e-07 2.46e-07 1.96e-07 7.78e-07 9.00e-07 erg/cm2
Error 2.40e-08 2.64e-08 3.96e-08 2.28e-07 9.34e-08 2.55e-07 erg/cm2
Peak flux Band 2.37e-01 2.44e-01 1.67e-01 1.69e-01 7.17e-01 8.17e-01 ph/cm2/s
Error 7.12e-02 5.52e-02 3.98e-02 7.18e-02 1.19e-01 1.91e-01 ph/cm2/s
=== Time-averaged spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.967 0.160 - - 1.16e-03 1.19e-04 53.703 57
CPL 1.304 0.683 45.3 41.3 2.72e-03 3.00e-03 51.694 0
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.524 0.290 - - 5.73e-03 9.93e-04 49.124 57
CPL 1.405 1.204 239.4 5000.0 6.62e-03 1.17e-02 49.131 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: 29.952000 sec.
T50 in the 50-300 keV band: 15.040000 sec.
=== Table of the duration information ==
Value tstart tstop
T100 76.860 -14.432 62.428
T90 60.700 -0.904 59.796
T50 21.480 31.148 52.628
Peak 1.000 46.628 47.628
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
37.3301 -25.1452 0.0106 18.5 -14.1 1.5484 18.1 TRIG_00338633
------------------------------------------
Foreground time interval of the image:
-14.432 62.428 (delta_t = 76.860 [sec])
Background time interval of the image:
-260.195 -14.432 (delta_t = 245.763 [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.
- 4) For short bursts (T90<1sec), the specrtum is also fit with Blackbody, OTTB, and Double Blackbody.
Time averaged spectrum fit using the pre-slew DRM
Power-law model
Time interval is from -14.432 sec. to 62.428 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.96678 ( -0.156674 0.163831 )
Norm@50keV : 1.160517E-03 ( -1.202013E-04 1.179294E-04) )
------------------------------------------------------------
Chi-Squared = 53.70275 using 59 PHA bins.
Reduced chi-squared = 0.9421536 for 57 degrees of freedom
Null hypothesis probability = 0.600
Photon flux (15-150 keV) in 76.86 sec: 0.171472 ( -0.014012 0.014018 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.21334e-07 ( -8.05001e-08 8.19712e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -14.432 sec. to 62.428 sec.
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.30395 ( -0.607519 0.759153 )
Epeak [keV] : 45.2796 ( -45.2696 37.4032 )
Norm@50keV : 2.717226E-03 ( -2.717226E-03 3.281301E-03) )
------------------------------------------------------------
Chi-Squared = 51.69442 using 59 PHA bins.
but latest trial 82.6828 gives Chi-Squared = 8.24366
Reduced chi-squared = 0.9231146 for 56 degrees of freedom
Null hypothesis probability = 0.638
Photon flux (15-150 keV) in 76.86 sec: 0.167165 ( -0.014842 0.014831 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.78576e-07 ( -9.19576e-08 9.48299e-08 ) ergs/cm2
Band function
Time interval is from -14.432 sec. to 62.428 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.46190 ( -8.53810 0.747655 )
beta : -8.39886 ( -1.60114 6.50054 )
Epeak [keV] : 45.8972 ( -25.6765 9954.10 )
Norm@50keV : 2.230438E-03 ( -2.230438E-03 3.645698E-03) )
------------------------------------------------------------
Chi-Squared = 51.58183 using 59 PHA bins.
Reduced chi-squared = 0.9378515 for 55 degrees of freedom
Null hypothesis probability = 0.606
Photon flux (15-150 keV) in 76.86 sec: 0.167168 ( -0.014846 0.014831 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.77585e-07 ( -9.1923e-08 9.49759e-08 ) ergs/cm2
Peak spectrum fit using the pre-slew DRM
Power-law model
Time interval is from 46.628 sec. to 47.628 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.52434 ( -0.286688 0.293473 )
Norm@50keV : 5.733253E-03 ( -1.002069E-03 9.829821E-04) )
------------------------------------------------------------
Chi-Squared = 49.12355 using 59 PHA bins.
Reduced chi-squared = 0.8618166 for 57 degrees of freedom
Null hypothesis probability = 0.762
Photon flux (15-150 keV) in 1.000 sec: 0.720521 ( -0.118892 0.119004 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.41821e-08 ( -1.02785e-08 1.04621e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 46.628 sec. to 47.628 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.40511 ( -1.21056 1.19655 )
Epeak [keV] : 239.384 ( -239.374 9760.62 )
Norm@50keV : 6.623784E-03 ( -1.886115E-03 2.144207E-02) )
------------------------------------------------------------
Chi-Squared = 49.13119 using 59 PHA bins.
Reduced chi-squared = 0.8773426 for 56 degrees of freedom
Null hypothesis probability = 0.730
Photon flux (15-150 keV) in 1.000 sec: 0.718961 ( -0.121477 0.120047 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.37696e-08 ( -1.12603e-08 1.08841e-08 ) ergs/cm2
Band function
Time interval is from 46.628 sec. to 47.628 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.07892 ( -8.92108 5.33934 )
beta : -1.55331 ( -8.44669 0.311864 )
Epeak [keV] : 59.1490 ( -59.0490 9940.85 )
Norm@50keV : 1.172930E-02 ( -553.614 123.584 )
------------------------------------------------------------
Chi-Squared = 49.05210 using 59 PHA bins.
Reduced chi-squared = 0.8918564 for 55 degrees of freedom
Null hypothesis probability = 0.700
Photon flux (15-150 keV) in 1.000 sec: 0.717462 ( -0.117994 0.120108 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.39258e-08 ( -1.14571e-08 1.06607e-08 ) ergs/cm2
Plot creation:
Wed Dec 31 09:11:48 EST 2008