batgrbproduct Analysis for Trigger=307931
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): Sun Mar 30 20:53:27 EDT 2008
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger307931/SDC
======================================================================
Trigger: 00307931 Segment: 000
BAT Trigger Time: 228384187.264 [s; MET]
Trigger Stop: 228384188.288 [s; MET]
UTC: 2008-03-28T08:03:04.588480 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 80.4787347010336 Dec: 47.5240403992213 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 15.28
Image Trigger?: NO
Rate S/N Ratio: 44.2492937796752 [ if not an image trigger ]
Image S/N Ratio: 15.28
Flight Position: [ source = BAT ]
RA: 80.4787347010336 Dec: 47.5240403992213 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 80.4898416631501 Dec: 47.5225864239297 [deg; J2000]
{ 05h 21m 57.6s , +47d 31' 21.3" }
+/- 0.653210124553351 [arcmin] (estimated 90% radius based on SNR)
+/- 0.25934675044872 [arcmin] (formal 1-sigma fit error)
SNR: 55.8892796473882
RA = 5h 21m 57.6s (80.489842 deg.)
Dec = 47d 31' 21" (47.522586 deg.)
Angular difference between Flight and Ground position is 0.458403 arcmin
Partial Coding Fraction: 0.3710938 [ including projection effects ]
Duration
T90: 90.2080000042915 +/- 1.42857690277162
Measured from: 0.0760000050067902
to: 90.2840000092983 [s; relative to TRIGTIME]
T50: 65.7800000011921 +/- 1.19746396987325
Measured from: 9.96799999475479
to: 75.7479999959469 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 9.28000000119209
to: 10.2800000011921 [s; relative to TRIGTIME]
Total Fluence
Measured from: -2.24399998784065
to: 111.439999997616 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 3.771485 4.941622 4.248380 1.284061
0.077938 0.081285 0.075357 0.065972 [error]
Peak 0.100444 0.206321 0.280844 0.120488
0.010949 0.012786 0.014112 0.011762 [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 1.30e-06 2.35e-06 3.27e-06 9.52e-06 9.40e-06 1.64e-05 erg/cm2
Error 6.46e-08 6.67e-08 8.04e-08 5.70e-07 2.05e-07 5.88e-07 erg/cm2
Peak flux Power-law 1.10e+00 1.59e+00 1.72e+00 3.45e+00 5.48e+00 7.86e+00 ph/cm2/s
Error 1.51e-01 1.33e-01 1.04e-01 4.59e-01 3.46e-01 5.04e-01 ph/cm2/s
Fluence Cutoff-PL 1.26e-06 2.35e-06 3.30e-06 8.70e-06 9.37e-06 1.56e-05 erg/cm2
Error 7.78e-08 6.63e-08 9.99e-08 1.42e-06 2.21e-07 1.43e-06 erg/cm2
Peak flux Cutoff-PL 1.05e+00 1.60e+00 1.76e+00 2.96e+00 5.45e+00 7.49e+00 ph/cm2/s
Error 1.97e-01 1.37e-01 1.38e-01 9.08e-01 2.59e-01 1.01e+00 ph/cm2/s
Fluence Band 1.25e-06 2.34e-06 3.29e-06 8.76e-06 9.36e-06 1.50e-05 erg/cm2
Error 8.88e-08 6.75e-08 9.97e-08 1.06e-06 2.20e-07 0.00e+00 erg/cm2
Peak flux Band 1.03e+00 1.61e+00 1.76e+00 3.17e+00 5.43e+00 7.57e+00 ph/cm2/s
Error 2.43e-01 1.41e-01 1.42e-01 5.84e-01 2.75e-01 6.76e-01 ph/cm2/s
=== Time-averaged spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.521 0.043 - - 8.74e-03 1.93e-04 44.323 57
CPL 1.437 0.148 402.9 5000.0 9.48e-03 1.29e-03 43.866 56
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 0.892 0.107 - - 4.77e-02 3.00e-03 63.455 57
CPL 0.732 0.365 495.3 5000.0 5.56e-02 2.04e-02 62.982 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: 87.168000 sec.
T50 in the 50-300 keV band: 25.216000 sec.
=== Table of the duration information ==
Value tstart tstop
T100 113.684 -2.244 111.440
T90 90.208 0.076 90.284
T50 65.780 9.968 75.748
Peak 1.000 9.280 10.280
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
80.4898 +47.5226 0.0035 45.0 2.0 7.0978 55.9 TRIG_00307931
------------------------------------------
Foreground time interval of the image:
-2.244 23.341 (delta_t = 25.585 [sec])
Background time interval of the image:
-239.264 -2.244 (delta_t = 237.020 [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 -2.244 sec. to 111.440 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.52140 ( -4.345310E-02 4.340732E-02) )
Norm@50keV : 8.744957E-03 ( -1.927102E-04 1.925295E-04) )
------------------------------------------------------------
Chi-Squared = 44.32313 using 59 PHA bins.
Reduced chi-squared = 0.7775987 for 57 degrees of freedom
Null hypothesis probability = 0.890
Photon flux (15-150 keV) in 113.7 sec: 1.09812 ( -0.02962 0.0298 ) ph/cm2/s
Energy fluence (15-150 keV) : 9.40039e-06 ( -2.04569e-07 2.04592e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -2.244 sec. to 111.440 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.43732 ( -0.174643 0.121307 )
Epeak [keV] : 402.873 ( -402.863 9597.13 )
Norm@50keV : 9.479201E-03 ( -8.864999E-04 1.683641E-03) )
------------------------------------------------------------
Chi-Squared = 43.86578 using 59 PHA bins.
Reduced chi-squared = 0.7833174 for 56 degrees of freedom
Null hypothesis probability = 0.880
Photon flux (15-150 keV) in 113.7 sec: 1.09082 ( -0.01746 0.03405 ) ph/cm2/s
Energy fluence (15-150 keV) : 9.36712e-06 ( -2.17087e-07 2.24421e-07 ) ergs/cm2
Band function
Time interval is from -2.244 sec. to 111.440 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.38345 ( -8.61655 0.440833 )
beta : -1.56074 ( -8.43926 7.730460E-02) )
Epeak [keV] : 230.020 ( -229.920 9769.98 )
Norm@50keV : 1.013720E-02 ( -1.278006E-03 227.926 )
------------------------------------------------------------
Chi-Squared = 43.87297 using 59 PHA bins.
Reduced chi-squared = 0.7976903 for 55 degrees of freedom
Null hypothesis probability = 0.859
Photon flux (15-150 keV) in 113.7 sec: 1.08787 ( -0.03879 0.03574 ) ph/cm2/s
Energy fluence (15-150 keV) : 9.36189e-06 ( -2.20987e-07 2.19975e-07 ) ergs/cm2
Peak spectrum fit using the pre-slew DRM
Power-law model
Time interval is from 9.280 sec. to 10.280 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.892267 ( -0.108248 0.105821 )
Norm@50keV : 4.773314E-02 ( -3.016394E-03 2.990305E-03) )
------------------------------------------------------------
Chi-Squared = 63.45524 using 59 PHA bins.
Reduced chi-squared = 1.113250 for 57 degrees of freedom
Null hypothesis probability = 0.259
Photon flux (15-150 keV) in 1.000 sec: 5.47843 ( -0.34525 0.34597 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.37319e-07 ( -3.2988e-08 3.3002e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 9.280 sec. to 10.280 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.731764 ( -0.478967 0.251158 )
Epeak [keV] : 495.290 ( -495.280 9504.71 )
Norm@50keV : 5.564219E-02 ( -1.035692E-02 3.050868E-02) )
------------------------------------------------------------
Chi-Squared = 62.98187 using 59 PHA bins.
Reduced chi-squared = 1.124676 for 56 degrees of freedom
Null hypothesis probability = 0.243
Photon flux (15-150 keV) in 1.000 sec: 5.45313 ( -0.17469 0.34231 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.37089e-07 ( -3.3105e-08 3.3179e-08 ) ergs/cm2
Band function
Time interval is from 9.280 sec. to 10.280 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.793760 ( -9.20624 5.79376 )
beta : -0.892270 ( -0.105797 0.108294 )
Epeak [keV] : 24.9035 ( -1.32910 9.765625E-04) )
Norm@50keV : 7.220993E-02 ( -3.024291E-03 2.997126E-03) )
------------------------------------------------------------
Chi-Squared = 63.45523 using 59 PHA bins.
Reduced chi-squared = 1.153731 for 55 degrees of freedom
Null hypothesis probability = 0.203
Photon flux (15-150 keV) in 1.000 sec: 5.43348 ( -0.36619 0.18363 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.36765e-07 ( -3.3291e-08 3.3238e-08 ) ergs/cm2
Plot creation:
Sun Mar 30 21:54:01 EDT 2008