batgrbproduct Analysis for Trigger=323870
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 Sep 5 16:17:17 EDT 2008
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger323870/GCN5_download_cron
======================================================================
Trigger: 00323870 Segment: 000
BAT Trigger Time: 242308738.048 [s; MET]
Trigger Stop: 242308738.304 [s; MET]
UTC: 2008-09-05T11:58:54.973940 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 287.661676067797 Dec: -18.8772722987606 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 6.87
Image Trigger?: NO
Rate S/N Ratio: 29.0344622819159 [ if not an image trigger ]
Image S/N Ratio: 6.87
Flight Position: [ source = BAT ]
RA: 287.661676067797 Dec: -18.8772722987606 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 287.662789189239 Dec: -18.86584095122 [deg; J2000]
{ 19h 10m 39.1s , -18d 51' 57.0" }
+/- 2.1048487440089 [arcmin] (estimated 90% radius based on SNR)
+/- 0.761061806358671 [arcmin] (formal 1-sigma fit error)
SNR: 10.5044724828974
Angular difference between Flight and Ground position is 0.688786 arcmin
Partial Coding Fraction: 0.5625 [ including projection effects ]
Duration
T90: 1.01600003242493 +/- 0.0815843255901954
Measured from: 0.0480000674724579
to: 1.06400009989738 [s; relative to TRIGTIME]
T50: 0.787999987602234 +/- 0.113278437162009
Measured from: 0.16400009393692
to: 0.952000081539154 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 0.0399999916553497
to: 1.03999999165535 [s; relative to TRIGTIME]
Total Fluence
Measured from: 0.0399999916553497
to: 1.12799999117851 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.016658 0.061166 0.067162 0.029628
0.007514 0.007920 0.007893 0.007002 [error]
Peak 0.013422 0.055671 0.060976 0.028287
0.007173 0.007569 0.007591 0.006768 [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 8.54e-09 2.33e-08 5.19e-08 3.06e-07 1.40e-07 3.87e-07 erg/cm2
Error 2.56e-09 4.23e-09 6.95e-09 9.80e-08 1.89e-08 9.98e-08 erg/cm2
Peak flux Power-law 2.26e-01 3.51e-01 4.10e-01 9.22e-01 1.26e+00 1.91e+00 ph/cm2/s
Error 7.62e-02 7.26e-02 5.62e-02 2.91e-01 1.86e-01 2.93e-01 ph/cm2/s
Fluence Cutoff-PL 8.17e-09 2.35e-08 5.27e-08 2.68e-07 1.40e-07 2.95e-07 erg/cm2
Error 2.91e-09 4.21e-09 6.16e-09 1.59e-07 1.92e-08 0.00e+00 erg/cm2
Peak flux Cutoff-PL 2.24e-01 3.53e-01 4.10e-01 9.16e-01 1.26e+00 1.83e+00 ph/cm2/s
Error 7.64e-02 7.37e-02 5.63e-02 2.81e-01 1.86e-01 4.35e-01 ph/cm2/s
Fluence Band 8.19e-09 2.34e-08 5.25e-08 2.72e-07 1.40e-07 2.87e-07 erg/cm2
Error 2.88e-09 4.42e-09 8.23e-09 1.59e-07 1.93e-08 0.00e+00 erg/cm2
Peak flux Band 1.65e-01 3.85e-01 4.19e-01 8.38e-01 1.23e+00 1.81e+00 ph/cm2/s
Error 5.93e-02 7.18e-02 5.93e-02 2.29e-01 1.77e-01 3.07e-01 ph/cm2/s
=== Time-averaged spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 0.845 0.238 - - 1.12e-02 1.58e-03 57.534 57
CPL 0.838 0.239 9999.3 0.0 1.13e-02 1.05e-02 57.529 56
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 0.777 0.256 - - 1.09e-02 1.68e-03 61.054 57
CPL 0.740 0.275 9810.0 0.0 1.09e-02 1.68e-03 61.090 0
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: 1.024000 sec.
T50 in the 50-300 keV band: 0.832000 sec.
=== Table of the duration information ==
Value tstart tstop
T100 1.088 0.040 1.128
T90 1.016 0.048 1.064
T50 0.788 0.164 0.952
Peak 1.000 0.040 1.040
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
287.6628 -18.8658 0.0183 39.6 -6.5 0.1729 10.5 TRIG_00323870
------------------------------------------
Foreground time interval of the image:
0.040 1.128 (delta_t = 1.088 [sec])
Background time interval of the image:
-119.048 -111.378 (delta_t = 7.670 [sec])
-110.048 -109.008 (delta_t = 1.040 [sec])
-108.048 -106.818 (delta_t = 1.230 [sec])
-106.048 -97.508 (delta_t = 8.540 [sec])
-97.048 -91.748 (delta_t = 5.300 [sec])
-91.048 -88.758 (delta_t = 2.290 [sec])
-88.048 -87.898 (delta_t = 0.150 [sec])
-87.048 -77.348 (delta_t = 9.700 [sec])
-77.048 -49.398 (delta_t = 27.650 [sec])
-49.048 -33.968 (delta_t = 15.080 [sec])
-33.048 -32.038 (delta_t = 1.010 [sec])
-31.048 -27.548 (delta_t = 3.500 [sec])
-26.048 -5.688 (delta_t = 20.360 [sec])
-5.048 0.040 (delta_t = 5.088 [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 0.040 sec. to 1.128 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.845408 ( -0.245891 0.229205 )
Norm@50keV : 1.122468E-02 ( -1.600049E-03 1.565990E-03) )
------------------------------------------------------------
Chi-Squared = 57.53363 using 59 PHA bins.
Reduced chi-squared = 1.009362 for 57 degrees of freedom
Null hypothesis probability = 0.455
Photon flux (15-150 keV) in 1.088 sec: 1.28860 ( -0.17892 0.17998 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.40064e-07 ( -1.88289e-08 1.89029e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.040 sec. to 1.128 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.838391 ( -0.247963 0.230919 )
Epeak [keV] : 9999.33 ( )
Norm@50keV : 1.130312E-02 ( -2.425040E-03 1.859771E-02) )
------------------------------------------------------------
Chi-Squared = 57.52946 using 59 PHA bins.
Reduced chi-squared = 1.027312 for 56 degrees of freedom
Null hypothesis probability = 0.418
Photon flux (15-150 keV) in 1.088 sec: 1.28565 ( -0.17563 0.17866 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.39656e-07 ( -1.91249e-08 1.92478e-08 ) ergs/cm2
Band function
Time interval is from 0.040 sec. to 1.128 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.737484 ( -14.9998 2.174377E-04) )
beta : -0.845422 ( -0.409792 0.233627 )
Epeak [keV] : 38.7115 ( )
Norm@50keV : 1.676197E-02 ( )
------------------------------------------------------------
Chi-Squared = 57.53363 using 59 PHA bins.
Reduced chi-squared = 1.046066 for 55 degrees of freedom
Null hypothesis probability = 0.382
Photon flux (15-150 keV) in 1.088 sec: 1.25911 ( -0.17498 0.16879 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.39673e-07 ( -1.94023e-08 1.91564e-08 ) ergs/cm2
Peak spectrum fit using the pre-slew DRM
Power-law model
Time interval is from 0.040 sec. to 1.040 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.777178 ( -0.267207 0.245770 )
Norm@50keV : 1.093286E-02 ( -1.702371E-03 1.652336E-03) )
------------------------------------------------------------
Chi-Squared = 61.05412 using 59 PHA bins.
Reduced chi-squared = 1.071125 for 57 degrees of freedom
Null hypothesis probability = 0.332
Photon flux (15-150 keV) in 1.000 sec: 1.25770 ( -0.18546 0.18675 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.28941e-07 ( -1.8104e-08 1.8247e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.040 sec. to 1.040 sec.
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.740083 ( -0.270358 0.278971 )
Epeak [keV] : 9809.99 ( )
Norm@50keV : 1.092351E-02 ( -1.708058E-03 1.658134E-03) )
------------------------------------------------------------
Chi-Squared = 61.08955 using 59 PHA bins.
but latest trial 0.469627 gives Chi-Squared = 0.246830
Reduced chi-squared = 1.090885 for 56 degrees of freedom
Null hypothesis probability = 0.298
Photon flux (15-150 keV) in 1.000 sec: 1.25742 ( -0.18539 0.18669 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.29111e-07 ( -1.8214e-08 1.8167e-08 ) ergs/cm2
Band function
Time interval is from 0.040 sec. to 1.040 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.748717 ( -9.25128 5.74872 )
beta : -0.777174 ( -0.245625 0.267204 )
Epeak [keV] : 18.2317 ( -18.1317 9981.77 )
Norm@50keV : 1.531593E-02 ( -6.022078E-03 284839. )
------------------------------------------------------------
Chi-Squared = 61.05412 using 59 PHA bins.
Reduced chi-squared = 1.110075 for 55 degrees of freedom
Null hypothesis probability = 0.268
Photon flux (15-150 keV) in 1.000 sec: 1.22674 ( -0.17824 0.17525 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.28952e-07 ( -1.8412e-08 1.822e-08 ) ergs/cm2
Plot creation:
Fri Sep 5 16:36:17 EDT 2008