batgrbproduct Analysis for Trigger=331856
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 Oct 17 09:53:37 EDT 2008
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger331856/GCN5_download_cron
======================================================================
Trigger: 00331856 Segment: 000
BAT Trigger Time: 245879237.696 [s; MET]
Trigger Stop: 245879239.744 [s; MET]
UTC: 2008-10-16T19:47:14.515960 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 14.6151239564649 Dec: -43.5430521619781 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 7.48
Image Trigger?: NO
Rate S/N Ratio: 19.6977156035922 [ if not an image trigger ]
Image S/N Ratio: 7.48
Flight Position: [ source = BAT ]
RA: 14.6151239564649 Dec: -43.5430521619781 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 14.5823675398395 Dec: -43.5355403199613 [deg; J2000]
{ 00h 58m 19.8s , -43d 32' 07.9" }
+/- 2.27373171756348 [arcmin] (estimated 90% radius based on SNR)
+/- 1.01089950125502 [arcmin] (formal 1-sigma fit error)
SNR: 9.40786166388258
Angular difference between Flight and Ground position is 1.494304 arcmin
Partial Coding Fraction: 0.984375 [ including projection effects ]
Duration
T90: 2.64400002360344 +/- 0.793745547045134
Measured from: 0.180000066757202
to: 2.82400009036064 [s; relative to TRIGTIME]
T50: 0.936000019311905 +/- 0.329611881397209
Measured from: 0.772000074386597
to: 1.7080000936985 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 0.503999978303909
to: 1.50399997830391 [s; relative to TRIGTIME]
Total Fluence
Measured from: -0.0200000107288361
to: 2.95600000023842 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.020883 0.044054 0.048688 0.028531
0.007801 0.008063 0.007267 0.006375 [error]
Peak 0.010278 0.016430 0.028294 0.016338
0.004554 0.004748 0.004411 0.003867 [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 6.69e-09 1.74e-08 3.68e-08 2.00e-07 9.92e-08 2.64e-07 erg/cm2
Error 2.51e-09 3.89e-09 6.81e-09 9.08e-08 1.82e-08 9.33e-08 erg/cm2
Peak flux Power-law 8.09e-02 1.37e-01 1.76e-01 4.54e-01 5.18e-01 8.47e-01 ph/cm2/s
Error 4.12e-02 4.20e-02 3.36e-02 2.09e-01 1.06e-01 2.03e-01 ph/cm2/s
Fluence Cutoff-PL 6.60e-09 1.75e-08 3.69e-08 1.99e-07 9.93e-08 1.95e-07 erg/cm2
Error 2.72e-09 3.90e-09 6.82e-09 9.02e-08 1.82e-08 0.00e+00 erg/cm2
Peak flux Cutoff-PL 8.07e-02 1.37e-01 1.76e-01 4.51e-01 5.18e-01 8.44e-01 ph/cm2/s
Error 4.12e-02 4.20e-02 3.36e-02 2.08e-01 1.06e-01 2.02e-01 ph/cm2/s
Fluence Band 6.05e-09 1.78e-08 3.73e-08 1.82e-07 9.81e-08 2.41e-07 erg/cm2
Error 3.96e-09 4.66e-09 7.37e-09 9.90e-08 1.78e-08 1.25e-07 erg/cm2
Peak flux Band 8.12e-02 1.37e-01 1.76e-01 4.51e-01 5.18e-01 8.02e-01 ph/cm2/s
Error 4.26e-02 4.21e-02 3.37e-02 2.08e-01 8.08e-02 2.94e-01 ph/cm2/s
=== Time-averaged spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 0.921 0.320 - - 2.99e-03 5.31e-04 42.000 57
CPL 0.915 0.323 9999.2 5000.0 3.01e-03 5.32e-04 42.000 56
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 0.639 0.391 - - 4.46e-03 1.00e-03 46.493 57
CPL 0.630 0.395 9995.4 4887.7 4.49e-03 1.00e-03 46.494 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: 1.344000 sec.
T50 in the 50-300 keV band: 0.704000 sec.
=== Table of the duration information ==
Value tstart tstop
T100 2.976 -0.020 2.956
T90 2.644 0.180 2.824
T50 0.936 0.772 1.708
Peak 1.000 0.504 1.504
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
14.5824 -43.5355 0.0205 17.3 13.0 0.1486 9.4 TRIG_00331856
------------------------------------------
Foreground time interval of the image:
-0.020 2.956 (delta_t = 2.976 [sec])
Background time interval of the image:
-239.696 -0.020 (delta_t = 239.676 [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 -0.020 sec. to 2.956 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.920882 ( -0.332600 0.308279 )
Norm@50keV : 2.994476E-03 ( -5.349515E-04 5.260655E-04) )
------------------------------------------------------------
Chi-Squared = 41.99952 using 59 PHA bins.
Reduced chi-squared = 0.7368336 for 57 degrees of freedom
Null hypothesis probability = 0.932
Photon flux (15-150 keV) in 2.976 sec: 0.343791 ( -0.061114 0.061566 ) ph/cm2/s
Energy fluence (15-150 keV) : 9.91922e-08 ( -1.81232e-08 1.832e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.020 sec. to 2.956 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.914635 ( -0.335304 0.310410 )
Epeak [keV] : 9999.21 ( -9999.20 0.787109 )
Norm@50keV : 3.013866E-03 ( -5.365531E-04 5.281542E-04) )
------------------------------------------------------------
Chi-Squared = 42.00020 using 59 PHA bins.
Reduced chi-squared = 0.7500035 for 56 degrees of freedom
Null hypothesis probability = 0.917
Photon flux (15-150 keV) in 2.976 sec: 0.343692 ( -0.061097 0.061429 ) ph/cm2/s
Energy fluence (15-150 keV) : 9.92561e-08 ( -1.81685e-08 1.82923e-08 ) ergs/cm2
Band function
Time interval is from -0.020 sec. to 2.956 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.819511 ( -9.18049 5.81951 )
beta : -0.920882 ( -0.308256 0.332601 )
Epeak [keV] : 34.7138 ( -34.6138 9965.29 )
Norm@50keV : 4.410485E-03 ( -1.927503E-03 1346.08 )
------------------------------------------------------------
Chi-Squared = 41.99952 using 59 PHA bins.
Reduced chi-squared = 0.7636275 for 55 degrees of freedom
Null hypothesis probability = 0.901
Photon flux (15-150 keV) in 2.976 sec: 0.340170 ( -0.06552 0.061649 ) ph/cm2/s
Energy fluence (15-150 keV) : 9.80785e-08 ( -1.7748e-08 1.78997e-08 ) ergs/cm2
Peak spectrum fit using the pre-slew DRM
Power-law model
Time interval is from 0.504 sec. to 1.504 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.638624 ( -0.414709 0.367812 )
Norm@50keV : 4.456746E-03 ( -1.029480E-03 9.734989E-04) )
------------------------------------------------------------
Chi-Squared = 46.49325 using 59 PHA bins.
Reduced chi-squared = 0.8156711 for 57 degrees of freedom
Null hypothesis probability = 0.839
Photon flux (15-150 keV) in 1.000 sec: 0.518073 ( -0.10551 0.106653 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.59567e-08 ( -1.11801e-08 1.12529e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.504 sec. to 1.504 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.629598 ( -0.418742 0.370920 )
Epeak [keV] : 9995.41 ( -9770.85 4.58691 )
Norm@50keV : 4.487553E-03 ( -1.028168E-03 9.817118E-04) )
------------------------------------------------------------
Chi-Squared = 46.49386 using 59 PHA bins.
Reduced chi-squared = 0.8302475 for 56 degrees of freedom
Null hypothesis probability = 0.813
Photon flux (15-150 keV) in 1.000 sec: 0.517912 ( -0.105467 0.106607 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.60086e-08 ( -1.12148e-08 1.1218e-08 ) ergs/cm2
Band function
Time interval is from 0.504 sec. to 1.504 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.927876 ( -9.07212 5.92788 )
beta : -0.638628 ( -0.367789 0.414713 )
Epeak [keV] : 13.1243 ( -13.0243 9986.88 )
Norm@50keV : 6.656977E-03 ( -3.190425E-03 83252.7 )
------------------------------------------------------------
Chi-Squared = 46.49325 using 59 PHA bins.
Reduced chi-squared = 0.8453318 for 55 degrees of freedom
Null hypothesis probability = 0.786
Photon flux (15-150 keV) in 1.000 sec: 0.517911 ( -0.054938 0.106621 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.59324e-08 ( -1.15203e-08 1.12583e-08 ) ergs/cm2
Plot creation:
Fri Oct 17 10:19:16 EDT 2008