batgrbproduct Analysis for Trigger=318832
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): Sat Aug 2 18:48:22 EDT 2008
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger318832/SDC
======================================================================
Trigger: 00318832 Segment: 000
BAT Trigger Time: 239382744.064 [s; MET]
Trigger Stop: 239382748.16 [s; MET]
UTC: 2008-08-02T15:12:21.075860 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 270.748505066349 Dec: -32.3332776459289 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 7.06
Image Trigger?: NO
Rate S/N Ratio: 8.30662386291807 [ if not an image trigger ]
Image S/N Ratio: 7.06
Flight Position: [ source = BAT ]
RA: 270.748505066349 Dec: -32.3332776459289 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 270.7293429085 Dec: -32.3293221008975 [deg; J2000]
{ 18h 02m 55.0s , -32d 19' 45.6" }
+/- 1.56838190389984 [arcmin] (estimated 90% radius based on SNR)
+/- 0.738960862706656 [arcmin] (formal 1-sigma fit error)
SNR: 15.9919524709473
Angular difference between Flight and Ground position is 1.000057 arcmin
Partial Coding Fraction: 1.015625 [ including projection effects ]
Duration
T90: 176 +/- 50.5964425626941
Measured from: -31.0640000104904
to: 144.93599998951 [s; relative to TRIGTIME]
T50: 80 +/- 16
Measured from: -15.0640000104904
to: 64.9359999895096 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: -7.56400001049042
to: -6.56400001049042 [s; relative to TRIGTIME]
Total Fluence
Measured from: -31.0640000104904
to: 176.93599998951 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.824563 0.943601 0.490307 0.222442
0.087180 0.079828 0.071537 0.069973 [error]
Peak 0.170060 0.186832 0.134453 0.037831
0.024584 0.022389 0.020185 0.019590 [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 2.22e-07 3.50e-07 4.15e-07 9.54e-07 1.26e-06 1.95e-06 erg/cm2
Error 3.51e-08 3.60e-08 6.72e-08 3.17e-07 1.56e-07 3.82e-07 erg/cm2
Peak flux Power-law 8.62e-02 8.38e-02 5.69e-02 6.06e-02 2.51e-01 2.88e-01 ph/cm2/s
Error 1.95e-02 1.14e-02 1.05e-02 2.33e-02 3.31e-02 3.87e-02 ph/cm2/s
Fluence Cutoff-PL 2.05e-07 3.81e-07 4.02e-07 2.72e-07 1.15e-06 1.26e-06 erg/cm2
Error 4.03e-08 4.95e-08 7.90e-08 5.06e-07 1.86e-07 5.05e-07 erg/cm2
Peak flux Cutoff-PL 8.59e-02 8.39e-02 5.69e-02 6.02e-02 2.51e-01 2.82e-01 ph/cm2/s
Error 1.95e-02 1.14e-02 1.05e-02 2.31e-02 3.31e-02 4.84e-02 ph/cm2/s
Fluence Band 2.02e-07 3.84e-07 3.90e-07 5.84e-07 1.18e-06 1.57e-06 erg/cm2
Error 4.12e-08 5.11e-08 7.89e-08 4.95e-07 1.71e-07 4.28e-07 erg/cm2
Peak flux Band 8.62e-02 8.39e-02 5.69e-02 6.01e-02 2.51e-01 2.87e-01 ph/cm2/s
Error 1.97e-02 1.24e-02 1.05e-02 2.31e-02 3.31e-02 3.86e-02 ph/cm2/s
=== Time-averaged spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.756 0.190 - - 6.59e-04 7.79e-05 50.019 57
CPL 0.968 0.917 56.1 4978.6 1.83e-03 3.39e-03 47.401 56
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.559 0.248 - - 1.98e-03 2.77e-04 59.027 57
CPL 1.332 0.627 139.7 0.0 2.57e-03 2.16e-03 59.277 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: 20.352000 sec.
T50 in the 50-300 keV band: 8.576000 sec.
=== Table of the duration information ==
Value tstart tstop
T100 208.000 -31.064 176.936
T90 176.000 -31.064 144.936
T50 80.000 -15.064 64.936
Peak 1.000 -7.564 -6.564
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
270.7293 -32.3293 0.0121 4.9 173.5 1.7168 16.0 TRIG_00318832
------------------------------------------
Foreground time interval of the image:
-31.064 45.141 (delta_t = 76.205 [sec])
Background time interval of the image:
-239.064 -237.916 (delta_t = 1.148 [sec])
-236.064 -235.841 (delta_t = 0.223 [sec])
-235.064 -234.617 (delta_t = 0.447 [sec])
-233.064 -227.791 (delta_t = 5.273 [sec])
-227.064 -31.064 (delta_t = 196.000 [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 -31.064 sec. to 176.936 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.75563 ( -0.187376 0.193022 )
Norm@50keV : 6.591029E-04 ( -7.852144E-05 7.725827E-05) )
------------------------------------------------------------
Chi-Squared = 50.01943 using 59 PHA bins.
Reduced chi-squared = 0.8775339 for 57 degrees of freedom
Null hypothesis probability = 0.732
Photon flux (15-150 keV) in 208.0 sec: 8.930766E-02 ( -0.00921489 0.00922057 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.26473e-06 ( -1.5449e-07 1.57787e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -31.064 sec. to 176.936 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.967924 ( -1.01491 0.818532 )
Epeak [keV] : 56.1497 ( -13.4018 9943.85 )
Norm@50keV : 1.828932E-03 ( -1.828932E-03 4.960684E-03) )
------------------------------------------------------------
Chi-Squared = 47.40135 using 59 PHA bins.
Reduced chi-squared = 0.8464527 for 56 degrees of freedom
Null hypothesis probability = 0.787
Photon flux (15-150 keV) in 208.0 sec: 8.585617E-02 ( -0.00984375 0.00987145 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.15256e-06 ( -1.79076e-07 1.93417e-07 ) ergs/cm2
Band function
Time interval is from -31.064 sec. to 176.936 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.06052 ( -0.979330 5.48198 )
beta : -2.44292 ( -7.84451 0.470464 )
Epeak [keV] : 57.1145 ( -24.1209 228.404 )
Norm@50keV : 1.636698E-03 ( -1.69120 26.2247 )
------------------------------------------------------------
Chi-Squared = 47.26213 using 59 PHA bins.
Reduced chi-squared = 0.8593115 for 55 degrees of freedom
Null hypothesis probability = 0.761
Photon flux (15-150 keV) in 208.0 sec: 8.615613E-02 ( -0.00964183 0.00989792 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.18441e-06 ( -1.63889e-07 1.77568e-07 ) ergs/cm2
Peak spectrum fit using the pre-slew DRM
Power-law model
Time interval is from -15.064 sec. to 0.936 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.55867 ( -0.246136 0.250785 )
Norm@50keV : 1.980708E-03 ( -2.796955E-04 2.748871E-04) )
------------------------------------------------------------
Chi-Squared = 59.02724 using 59 PHA bins.
Reduced chi-squared = 1.035566 for 57 degrees of freedom
Null hypothesis probability = 0.401
Photon flux (15-150 keV) in 16.00 sec: 0.251380 ( -0.033118 0.033175 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.97976e-07 ( -4.5776e-08 4.68576e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -15.064 sec. to 0.936 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.33215 ( -0.765490 0.488491 )
Epeak [keV] : 139.666 ( )
Norm@50keV : 2.565428E-03 ( -4.181077E-04 3.898320E-03) )
------------------------------------------------------------
Chi-Squared = 59.27656 using 59 PHA bins.
Reduced chi-squared = 1.058510 for 56 degrees of freedom
Null hypothesis probability = 0.357
Photon flux (15-150 keV) in 16.00 sec: 0.251282 ( -0.033105 0.033163 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.97966e-07 ( -4.5752e-08 4.68864e-08 ) ergs/cm2
Band function
Time interval is from -15.064 sec. to 0.936 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.18688 ( -8.81312 6.05320 )
beta : -1.56145 ( -8.43855 0.247494 )
Epeak [keV] : 47.8567 ( -47.7567 9950.49 )
Norm@50keV : 3.922062E-03 ( -0.237107 1067.74 )
------------------------------------------------------------
Chi-Squared = 58.99458 using 59 PHA bins.
Reduced chi-squared = 1.072629 for 55 degrees of freedom
Null hypothesis probability = 0.332
Photon flux (15-150 keV) in 16.00 sec: 0.251296 ( -0.033121 0.033116 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.96419e-07 ( -4.58816e-08 4.65792e-08 ) ergs/cm2
Plot creation:
Sat Aug 2 19:15:46 EDT 2008