batgrbproduct Analysis for Trigger=158262
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 Jan 10 19:38:49 EST 2008
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger158262/SDC
======================================================================
Trigger: 00158262 Segment: 000
BAT Trigger Time: 150117408 [s; MET]
Trigger Stop: 150117472 [s; MET]
UTC: 2005-10-04T11:16:48.235920 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 239.578782669113 Dec: -10.8689914897555 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 23
Image Trigger?: YES
Rate S/N Ratio: 0 [ if not an image trigger ]
Image S/N Ratio: 23
Flight Position: [ source = BAT ]
RA: 239.578782669113 Dec: -10.8689914897555 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 239.563550814244 Dec: -10.8455316078005 [deg; J2000]
{ 15h 58m 15.3s , -10d 50' 43.9" }
+/- 1.24714018772872 [arcmin] (estimated 90% radius based on SNR)
+/- 1.19959612999442 [arcmin] (formal 1-sigma fit error)
SNR: 22.1868966222096
RA = 15h 58m 15.3s (239.563551 deg.)
Dec = -10d 50' 44" (-10.845532 deg.)
Angular difference between Flight and Ground position is 1.669406 arcmin
Partial Coding Fraction: 1.015625 [ including projection effects ]
Duration
T90: 63.1680000126362 +/- 6.75022962516227
Measured from: -1.78000000119209
to: 61.3880000114441 [s; relative to TRIGTIME]
T50: 27.8400000035763 +/- 2.53840029173681
Measured from: 15
to: 42.8400000035763 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 42.2560000121593
to: 43.2560000121593 [s; relative to TRIGTIME]
Total Fluence
Measured from: -9.97999998927116
to: 69.5760000050068 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 2.685994 0.254613 0.050494 0.018796
0.050471 0.042850 0.035570 0.030047 [error]
Peak 0.049594 0.016367 0.007263 0.010644
0.005664 0.004759 0.003878 0.003302 [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 8.02e-07 1.18e-07 7.92e-09 5.65e-10 9.28e-07 9.28e-07 erg/cm2
Error 8.51e-08 2.08e-08 3.46e-09 4.29e-10 8.66e-08 8.65e-08 erg/cm2
Peak flux Power-law 5.17e-01 1.41e-01 2.06e-02 3.40e-03 6.81e-01 6.82e-01 ph/cm2/s
Error 1.12e-01 5.66e-02 2.03e-02 7.08e-03 1.28e-01 1.29e-01 ph/cm2/s
Fluence Cutoff-PL 8.01e-07 1.18e-07 7.90e-09 5.60e-10 9.28e-07 9.28e-07 erg/cm2
Error 8.50e-08 2.08e-08 3.46e-09 4.26e-10 8.65e-08 8.65e-08 erg/cm2
Peak flux Cutoff-PL 5.17e-01 1.41e-01 2.05e-02 3.37e-03 6.80e-01 6.81e-01 ph/cm2/s
Error 1.12e-01 5.66e-02 2.03e-02 7.02e-03 1.28e-01 1.29e-01 ph/cm2/s
Fluence Band 1.83e-07 1.81e-07 3.44e-08 8.91e-10 9.08e-07 6.26e-07 erg/cm2
Error 8.57e-08 0.00e+00 0.00e+00 0.00e+00 0.00e+00 0.00e+00 erg/cm2
Peak flux Band 5.03e-01 2.72e-01 5.81e-01 9.84e-02 1.82e+01 6.86e-01 ph/cm2/s
Error 2.75e+03 2.12e-01 3.15e+01 0.00e+00 0.00e+00 0.00e+00 ph/cm2/s
=== Time-averaged spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 5.899 0.386 - - 1.04e-04 3.68e-05 65.194 57
CPL 1.650 0.000 1.7 6.0 3.25e-01 4.55e+02 61.300 0
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 3.754 0.876 - - 1.36e-03 1.27e-03 57.021 57
CPL 1.913 1.100 1.0 0.0 4.38e-02 7.70e-02 60.832 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: 0.000000 sec.
T50 in the 50-300 keV band: 0.000000 sec.
=== Table of the duration information ==
Value tstart tstop
T100 79.556 -9.980 69.576
T90 63.168 -1.780 61.388
T50 27.840 15.000 42.840
Peak 1.000 42.256 43.256
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
239.5636 -10.8455 0.0085 6.5 -52.9 3.2187 22.2 TRIG_00158262
------------------------------------------
Foreground time interval of the image:
-9.980 69.576 (delta_t = 79.556 [sec])
Background time interval of the image:
-179.000 -9.980 (delta_t = 169.020 [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 -9.980 sec. to 69.576 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 5.89923 ( -0.383830 0.388019 )
Norm@50keV : 1.039152E-04 ( -3.172333E-05 4.184875E-05) )
------------------------------------------------------------
Chi-Squared = 65.19408 using 59 PHA bins.
Reduced chi-squared = 1.143756 for 57 degrees of freedom
Null hypothesis probability = 0.213
Photon flux (15-150 keV) in 79.56 sec: 0.386554 ( -0.038871 0.038986 ) ph/cm2/s
Energy fluence (15-150 keV) : 9.28449e-07 ( -8.64817e-08 8.67204e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -9.980 sec. to 69.576 sec.
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.64999 ( )
Epeak [keV] : 1.72641 ( -3.02664 9.06995 )
Norm@50keV : 0.325338 ( -0.586014 910.024 )
------------------------------------------------------------
Chi-Squared = 61.30011 using 59 PHA bins.
but latest trial 12.7491 gives Chi-Squared = 27.3574
Reduced chi-squared = 1.094645 for 56 degrees of freedom
Null hypothesis probability = 0.292
Photon flux (15-150 keV) in 79.56 sec: 0.384007 ( -0.041892 0.041529 ) ph/cm2/s
Energy fluence (15-150 keV) : 9.27749e-07 ( -8.62828e-08 8.67443e-08 ) ergs/cm2
Band function
Time interval is from -9.980 sec. to 69.576 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -9.12882 ( -0.871176 1.76757 )
beta : -5.89925 ( -0.387820 0.383861 )
Epeak [keV] : 259.649 ( -259.549 9740.35 )
Norm@50keV : 1.412293E-02 ( -4.305053E-03 5.688475E-03) )
------------------------------------------------------------
Chi-Squared = 65.19409 using 59 PHA bins.
Reduced chi-squared = 1.185347 for 55 degrees of freedom
Null hypothesis probability = 0.163
Photon flux (15-150 keV) in 79.56 sec: 0.385736 ( -0.036646 0.040733 ) ph/cm2/s
Energy fluence (15-150 keV) : 9.08209e-07 ( -9.50742e-08 7.62503e-08 ) ergs/cm2
Peak spectrum fit using the pre-slew DRM
Power-law model
Time interval is from 42.256 sec. to 43.256 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 3.75358 ( -0.750512 1.00101 )
Norm@50keV : 1.360791E-03 ( -1.360791E-03 1.173012E-03) )
------------------------------------------------------------
Chi-Squared = 57.02143 using 59 PHA bins.
Reduced chi-squared = 1.000376 for 57 degrees of freedom
Null hypothesis probability = 0.474
Photon flux (15-150 keV) in 1.000 sec: 0.680817 ( -0.128281 0.128113 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.51786e-08 ( -6.0134e-09 6.7876e-09 ) ergs/cm2
Cutoff power-law model
Time interval is from 42.256 sec. to 43.256 sec.
Parameters : value lower 90% higher 90%
Photon index: 1.91277 ( -0.815719 1.38363 )
Epeak [keV] : 1.00459 ( )
Norm@50keV : 4.375831E-02 ( -3.318523E-02 0.120757 )
------------------------------------------------------------
Chi-Squared = 60.83205 using 59 PHA bins.
but latest trial 1.10058 gives Chi-Squared = 0.992229
but latest trial 1.580807E-02 gives Chi-Squared = 1.62577
Reduced chi-squared = 1.086287 for 56 degrees of freedom
Null hypothesis probability = 0.306
Photon flux (15-150 keV) in 1.000 sec: 0.680369 ( -0.128236 0.128055 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.51672e-08 ( -6.0104e-09 6.7895e-09 ) ergs/cm2
Band function
Time interval is from 42.256 sec. to 43.256 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.51077 ( -4.51097 2.92119 )
beta : -3.04333 ( -0.984203 0.766735 )
Epeak [keV] : 6.07432 ( -5.97432 9993.93 )
Norm@50keV : 4.871924E-02 ( -0.113367 0.161257 )
------------------------------------------------------------
Chi-Squared = 59.88144 using 59 PHA bins.
Reduced chi-squared = 1.088753 for 55 degrees of freedom
Null hypothesis probability = 0.303
Photon flux (15-150 keV) in 1.000 sec: 18.2141 ( -18.2141 44.8658 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.49536e-08 ( -5.3181e-09 4.6401e-09 ) ergs/cm2
Plot creation:
Thu Jan 10 19:49:58 EST 2008