batgrbproduct Analysis for Trigger=331721
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 Oct 15 17:38:00 EDT 2008
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger331721/GCN5_download_cron
======================================================================
Trigger: 00331721 Segment: 000
BAT Trigger Time: 245758464 [s; MET]
Trigger Stop: 245758784 [s; MET]
UTC: 2008-10-15T10:14:20.823560 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 79.0501924680654 Dec: 17.297148501389 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: NO [ by BAT flight software ]
Image S/N Ratio: 7.82
Image Trigger?: YES
Rate S/N Ratio: 0 [ if not an image trigger ]
Image S/N Ratio: 7.82
Flight Position: [ source = BAT ]
RA: 79.0501924680654 Dec: 17.297148501389 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: Dec: [deg; J2000]
{ 00h 00m 00.0s , +00d 00' 00.0" }
+/- inf [arcmin] (estimated 90% radius based on SNR)
+/- 0 [arcmin] (formal 1-sigma fit error)
SNR:
Angular difference between Flight and Ground position is 4773.065512 arcmin
Partial Coding Fraction: 0.03369141 [ including projection effects ]
Duration
T90: 802.60799998045 +/- 68.1172241256339
Measured from: 27.3520000874996
to: 829.960000067949 [s; relative to TRIGTIME]
T50: 437.455999970436 +/- 69.1161665635242
Measured from: 206.232000082731
to: 643.688000053167 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 315.467999994755
to: 316.467999994755 [s; relative to TRIGTIME]
Total Fluence
Measured from: -11.4160000085831
to: 888.055999994278 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 13.433864 10.925353 5.888112 1.967207
0.553851 0.559324 0.496126 0.447828 [error]
Peak 0.092787 0.082157 0.042963 0.052691
0.026550 0.026824 0.026771 0.026321 [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 5.49e-06 5.90e-06 4.50e-06 5.60e-06 1.80e-05 2.15e-05 erg/cm2
Error 5.22e-07 3.49e-07 5.23e-07 1.32e-06 1.15e-06 1.86e-06 erg/cm2
Peak flux Power-law 8.06e-01 4.11e-01 1.29e-01 5.19e-02 1.38e+00 1.40e+00 ph/cm2/s
Error 5.47e-01 3.29e-01 1.59e-01 1.57e-01 7.52e-01 7.65e-01 ph/cm2/s
Fluence Cutoff-PL 5.49e-06 5.90e-06 4.50e-06 5.56e-06 1.80e-05 2.15e-05 erg/cm2
Error 5.22e-07 3.50e-07 5.24e-07 1.31e-06 1.15e-06 1.85e-06 erg/cm2
Peak flux Cutoff-PL 9.83e-01 4.15e-01 8.27e-03 7.94e-07 1.41e+00 1.41e+00 ph/cm2/s
Error 5.82e-01 2.46e-01 1.24e-01 4.28e-02 7.13e-01 7.13e-01 ph/cm2/s
Fluence Band 5.36e-06 5.88e-06 4.49e-06 5.61e-06 1.80e-05 2.06e-05 erg/cm2
Error 4.63e-07 3.46e-07 4.48e-07 6.94e-07 1.07e-06 0.00e+00 erg/cm2
Peak flux Band 8.51e-01 4.96e-01 5.21e-02 5.62e-03 1.41e+00 1.43e+00 ph/cm2/s
Error 5.72e-01 3.80e-01 8.87e-02 8.65e-02 7.01e-01 7.31e-01 ph/cm2/s
=== Time-averaged spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 2.391 0.136 - - 2.06e-03 1.66e-04 53.418 57
CPL 1.991 0.000 1.0 8.7 3.27e-03 4.48e-04 56.228 56
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 2.669 1.384 - - 6.29e-03 6.16e-03 71.936 57
CPL -2.452 0.000 20.9 7.2 6.49e+01 5.15e+02 70.363 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: 0.064000 sec.
T50 in the 50-300 keV band: 0.064000 sec.
=== Table of the duration information ==
Value tstart tstop
T100 899.472 -11.416 888.056
T90 802.608 27.352 829.960
T50 437.456 206.232 643.688
Peak 1.000 315.468 316.468
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
------------------------------------------
--> command terminated with status 0
Foreground time interval of the image:
-11.416 335.001 (delta_t = 346.417 [sec])
Background time interval of the image:
-239.000 -11.416 (delta_t = 227.584 [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 -11.416 sec. to 888.056 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.39051 ( -0.132827 0.139655 )
Norm@50keV : 2.056642E-03 ( -1.683109E-04 1.645228E-04) )
------------------------------------------------------------
Chi-Squared = 53.41804 using 59 PHA bins.
Reduced chi-squared = 0.9371586 for 57 degrees of freedom
Null hypothesis probability = 0.610
Photon flux (15-150 keV) in 899.5 sec: 0.378427 ( -0.023963 0.02411 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.80095e-05 ( -1.151e-06 1.1546e-06 ) ergs/cm2
Cutoff power-law model
Time interval is from -11.416 sec. to 888.056 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.99149 ( )
Epeak [keV] : 1.04066 ( -0.258620 17.1727 )
Norm@50keV : 3.272096E-03 ( -4.169585E-04 4.798712E-04) )
------------------------------------------------------------
Chi-Squared = 56.22751 using 59 PHA bins.
Reduced chi-squared = 1.004063 for 56 degrees of freedom
Null hypothesis probability = 0.466
Photon flux (15-150 keV) in 899.5 sec: 0.378205 ( -0.023948 0.024097 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.80066e-05 ( -1.14857e-06 1.15721e-06 ) ergs/cm2
Band function
Time interval is from -11.416 sec. to 888.056 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.60767 ( -4.27449 10.7255 )
beta : -2.37294 ( -0.139672 0.132839 )
Epeak [keV] : 10.6018 ( -10.5018 9989.40 )
Norm@50keV : 8.787609E-03 ( -2.287489E-02 2.236232E-02) )
------------------------------------------------------------
Chi-Squared = 53.98954 using 59 PHA bins.
Reduced chi-squared = 0.9816279 for 55 degrees of freedom
Null hypothesis probability = 0.513
Photon flux (15-150 keV) in 899.5 sec: 0.378156 ( -0.022271 0.023012 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.79804e-05 ( -1.05871e-06 1.07994e-06 ) ergs/cm2
Peak spectrum fit using the pre-slew DRM
Power-law model
Time interval is from 315.464 sec. to 316.472 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.66923 ( -1.19897 1.56915 )
Norm@50keV : 6.289879E-03 ( -6.289879E-03 6.037009E-03) )
------------------------------------------------------------
Chi-Squared = 71.93559 using 59 PHA bins.
Reduced chi-squared = 1.262028 for 57 degrees of freedom
Null hypothesis probability = 8.791E-02
Photon flux (15-150 keV) in 1.008 sec: 1.37560 ( -0.752217 0.75263 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.67691e-08 ( -3.89759e-08 4.79141e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 315.464 sec. to 316.472 sec.
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -2.45161 ( )
Epeak [keV] : 20.8673 ( -5.80672 8.56354 )
Norm@50keV : 64.9055 ( -147.360 882.648 )
------------------------------------------------------------
Chi-Squared = 70.36284 using 59 PHA bins.
but latest trial 14.6539 gives Chi-Squared = 0.473152
Reduced chi-squared = 1.256479 for 56 degrees of freedom
Null hypothesis probability = 9.380E-02
Photon flux (15-150 keV) in 1.008 sec: 1.40694 ( -0.709914 0.71656 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.23679e-08 ( -2.6628e-08 2.68774e-08 ) ergs/cm2
Band function
Time interval is from 315.464 sec. to 316.472 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.48598 ( -8.51402 6.48598 )
beta : -2.96803 ( -7.03197 6.32815 )
Epeak [keV] : 12.0870 ( -11.9870 9987.91 )
Norm@50keV : 4.514547E-02 ( -2236.02 4431.08 )
------------------------------------------------------------
Chi-Squared = 71.57084 using 59 PHA bins.
Reduced chi-squared = 1.301288 for 55 degrees of freedom
Null hypothesis probability = 6.596E-02
Photon flux (15-150 keV) in 1.008 sec: 1.41470 ( -0.701511 0.70109 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.42763e-08 ( -3.85907e-08 4.50342e-08 ) ergs/cm2
Plot creation:
Wed Oct 15 18:01:07 EDT 2008