batgrbproduct Analysis for Trigger=231974
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): Wed Jan 2 07:30:49 EST 2008
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger231974/SDC
======================================================================
Trigger: 00231974 Segment: 000
BAT Trigger Time: 181443811.072 [s; MET]
Trigger Stop: 181443819.264 [s; MET]
UTC: 2006-10-02T01:03:29.592060 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 220.345605609545 Dec: 48.7365696281697 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 8.16
Image Trigger?: NO
Rate S/N Ratio: 9.05538513813742 [ if not an image trigger ]
Image S/N Ratio: 8.16
Flight Position: [ source = BAT ]
RA: 220.345605609545 Dec: 48.7365696281697 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 220.3591796088 Dec: 48.7308103849378 [deg; J2000]
{ 14h 41m 26.2s , +48d 43' 50.9" }
+/- 1.75918220872549 [arcmin] (estimated 90% radius based on SNR)
+/- 0.897651414624023 [arcmin] (formal 1-sigma fit error)
SNR: 13.5729530060744
RA = 14h 41m 26.2s (220.359180 deg.)
Dec = 48d 43' 51" (48.730810 deg.)
Angular difference between Flight and Ground position is 0.638719 arcmin
Partial Coding Fraction: 0.390625 [ including projection effects ]
Duration
T90: 17.5920000076294 +/- 1.72699162056985
Measured from: -1.56799998879433
to: 16.0240000188351 [s; relative to TRIGTIME]
T50: 7.86400002241135 +/- 2.94145609289421
Measured from: 4.53999999165535
to: 12.4040000140667 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: -1.38400000333786
to: -0.38400000333786 [s; relative to TRIGTIME]
Total Fluence
Measured from: -2.34799998998642
to: 16.8680000007153 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.344144 0.377241 0.284758 0.045398
0.043274 0.039495 0.034214 0.028601 [error]
Peak 0.028462 0.040777 0.018572 0.003142
0.009834 0.008894 0.007802 0.006512 [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 1.20e-07 1.88e-07 2.21e-07 5.06e-07 6.77e-07 1.03e-06 erg/cm2
Error 2.36e-08 2.20e-08 3.43e-08 1.71e-07 8.09e-08 1.96e-07 erg/cm2
Peak flux Power-law 3.01e-01 2.73e-01 1.72e-01 1.65e-01 8.15e-01 9.10e-01 ph/cm2/s
Error 1.58e-01 8.84e-02 6.52e-02 1.34e-01 2.56e-01 2.69e-01 ph/cm2/s
Fluence Cutoff-PL 1.20e-07 1.88e-07 2.22e-07 5.03e-07 6.77e-07 9.72e-07 erg/cm2
Error 2.36e-08 2.20e-08 3.44e-08 1.70e-07 8.10e-08 2.62e-07 erg/cm2
Peak flux Cutoff-PL 2.95e-01 2.77e-01 1.73e-01 1.49e-01 8.12e-01 8.82e-01 ph/cm2/s
Error 1.70e-01 9.98e-02 7.00e-02 1.65e-01 2.57e-01 3.04e-01 ph/cm2/s
Fluence Band 1.17e-07 1.87e-07 2.22e-07 5.13e-07 6.78e-07 1.05e-06 erg/cm2
Error 1.28e-08 2.32e-08 2.30e-08 1.71e-07 7.94e-08 1.40e-07 erg/cm2
Peak flux Band 2.78e-01 2.94e-01 1.67e-01 1.37e-01 8.06e-01 8.77e-01 ph/cm2/s
Error 1.27e-01 1.12e-01 6.17e-02 2.55e-01 2.70e-01 0.00e+00 ph/cm2/s
=== Time-averaged spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.761 0.210 - - 3.82e-03 4.43e-04 64.464 57
CPL 1.738 0.000 715.2 5000.0 3.91e-03 3.47e-03 64.514 56
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.671 0.559 - - 6.19e-03 1.89e-03 67.443 57
CPL 1.433 1.661 114.4 0.0 8.24e-03 8.25e-02 67.473 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: 41.472000 sec.
T50 in the 50-300 keV band: 16.832000 sec.
=== Table of the duration information ==
Value tstart tstop
T100 19.216 -2.348 16.868
T90 17.592 -1.568 16.024
T50 7.864 4.540 12.404
Peak 1.000 -1.384 -0.384
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
220.3592 +48.7308 0.0143 46.1 -13.2 1.0813 13.6 TRIG_00231974
------------------------------------------
Foreground time interval of the image:
-2.348 16.868 (delta_t = 19.216 [sec])
Background time interval of the image:
-164.667 -2.348 (delta_t = 162.319 [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 -2.348 sec. to 16.868 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.76136 ( -0.208121 0.212537 )
Norm@50keV : 3.819568E-03 ( -4.460108E-04 4.403342E-04) )
------------------------------------------------------------
Chi-Squared = 64.46429 using 59 PHA bins.
Reduced chi-squared = 1.130952 for 57 degrees of freedom
Null hypothesis probability = 0.232
Photon flux (15-150 keV) in 19.22 sec: 0.518650 ( -0.061763 0.062073 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.76782e-07 ( -8.0428e-08 8.14236e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -2.348 sec. to 16.868 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.73791 ( )
Epeak [keV] : 715.213 ( -80.4121 9919.58 )
Norm@50keV : 3.908661E-03 ( -2.318577E-03 4.613023E-03) )
------------------------------------------------------------
Chi-Squared = 64.51385 using 59 PHA bins.
Reduced chi-squared = 1.152033 for 56 degrees of freedom
Null hypothesis probability = 0.203
Photon flux (15-150 keV) in 19.22 sec: 0.518431 ( -0.061737 0.062049 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.77071e-07 ( -8.07509e-08 8.12256e-08 ) ergs/cm2
Band function
Time interval is from -2.348 sec. to 16.868 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.34472 ( -8.65528 2.70899 )
beta : -1.76878 ( -8.23122 0.214236 )
Epeak [keV] : 34.3661 ( -34.2661 9965.63 )
Norm@50keV : 8.231916E-03 ( -33.6355 1783.77 )
------------------------------------------------------------
Chi-Squared = 64.42957 using 59 PHA bins.
Reduced chi-squared = 1.171447 for 55 degrees of freedom
Null hypothesis probability = 0.180
Photon flux (15-150 keV) in 19.22 sec: 0.513966 ( ) ph/cm2/s
Energy fluence (15-150 keV) : 6.78203e-07 ( -7.92537e-08 7.94593e-08 ) ergs/cm2
Peak spectrum fit using the pre-slew DRM
Power-law model
Time interval is from -1.384 sec. to -0.384 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.67136 ( -0.553970 0.563415 )
Norm@50keV : 6.193891E-03 ( -1.909407E-03 1.867611E-03) )
------------------------------------------------------------
Chi-Squared = 67.44314 using 59 PHA bins.
Reduced chi-squared = 1.183213 for 57 degrees of freedom
Null hypothesis probability = 0.162
Photon flux (15-150 keV) in 1.000 sec: 0.814564 ( -0.254299 0.257656 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.74719e-08 ( -1.8067e-08 1.84492e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -1.384 sec. to -0.384 sec.
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.43277 ( -2.39055 0.931365 )
Epeak [keV] : 114.399 ( )
Norm@50keV : 8.244747E-03 ( -2.145327E-03 0.162787 )
------------------------------------------------------------
Chi-Squared = 67.47332 using 59 PHA bins.
but latest trial 2.36408 gives Chi-Squared = 0.405159
Reduced chi-squared = 1.204881 for 56 degrees of freedom
Null hypothesis probability = 0.140
Photon flux (15-150 keV) in 1.000 sec: 0.811833 ( -0.254771 0.259847 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.70353e-08 ( -1.01117e-08 1.86148e-08 ) ergs/cm2
Band function
Time interval is from -1.384 sec. to -0.384 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.594853 ( -9.40515 5.59485 )
beta : -1.79017 ( -8.20983 0.638658 )
Epeak [keV] : 42.1512 ( -42.0512 522.224 )
Norm@50keV : 3.186214E-02 ( -127.049 175.088 )
------------------------------------------------------------
Chi-Squared = 67.13963 using 59 PHA bins.
Reduced chi-squared = 1.220721 for 55 degrees of freedom
Null hypothesis probability = 0.126
Photon flux (15-150 keV) in 1.000 sec: 0.806199 ( -0.264034 0.246821 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.61399e-08 ( -1.6529e-08 1.71425e-08 ) ergs/cm2
Plot creation:
Wed Jan 2 07:50:39 EST 2008