batgrbproduct Analysis for Trigger=151131
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): Tue Jan 8 16:50:41 EST 2008
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger151131/SDC
======================================================================
Trigger: 00151131 Segment: 000
BAT Trigger Time: 146161434.816 [s; MET]
Trigger Stop: 146161461.696 [s; MET]
UTC: 2005-08-19T16:23:55.132880 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 358.735497383504 Dec: 24.8535340564834 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 8.79
Image Trigger?: NO
Rate S/N Ratio: 9.9498743710662 [ if not an image trigger ]
Image S/N Ratio: 8.79
Flight Position: [ source = BAT ]
RA: 358.735497383504 Dec: 24.8535340564834 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 358.755893897853 Dec: 24.873397079742 [deg; J2000]
{ 23h 55m 01.4s , +24d 52' 24.2" }
+/- 2.04602395275097 [arcmin] (estimated 90% radius based on SNR)
+/- 0.892088445137981 [arcmin] (formal 1-sigma fit error)
SNR: 10.938561618401
RA = 23h 55m 1.4s (358.755894 deg.)
Dec = 24d 52' 24" (24.873397 deg.)
Angular difference between Flight and Ground position is 1.628878 arcmin
Partial Coding Fraction: 0.765625 [ including projection effects ]
Duration
T90: 48 +/- 22.6274169979695
Measured from: -11.8160000145435
to: 36.1839999854565 [s; relative to TRIGTIME]
T50: 16 +/- 16
Measured from: 4.18399998545647
to: 20.1839999854565 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 11.6839999854565
to: 12.6839999854565 [s; relative to TRIGTIME]
Total Fluence
Measured from: -11.8160000145435
to: 36.1839999854565 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.394056 0.319552 0.049791 0.021677
0.034801 0.035091 0.030000 0.025264 [error]
Peak 0.166671 0.141425 0.020550 0.025493
0.020050 0.020425 0.017308 0.014639 [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 1.31e-07 1.17e-07 7.28e-08 6.87e-08 3.50e-07 3.89e-07 erg/cm2
Error 1.95e-08 1.81e-08 2.31e-08 4.01e-08 5.55e-08 7.73e-08 erg/cm2
Peak flux Power-law 1.18e-01 5.86e-02 1.80e-02 7.01e-03 1.98e-01 2.01e-01 ph/cm2/s
Error 2.27e-02 1.16e-02 7.50e-03 5.27e-03 3.18e-02 3.27e-02 ph/cm2/s
Fluence Cutoff-PL 1.25e-07 1.34e-07 4.97e-08 4.69e-09 3.13e-07 3.14e-07 erg/cm2
Error 2.13e-08 2.41e-08 2.99e-08 2.22e-08 5.38e-08 5.86e-08 erg/cm2
Peak flux Cutoff-PL 1.13e-01 6.54e-02 1.43e-02 1.14e-03 1.94e-01 1.94e-01 ph/cm2/s
Error 2.46e-02 1.57e-02 9.47e-03 5.69e-03 3.19e-02 3.22e-02 ph/cm2/s
Fluence Band 1.24e-07 1.36e-07 4.57e-08 3.27e-09 3.08e-07 3.04e-07 erg/cm2
Error 1.53e-08 1.30e-08 1.09e-08 2.63e-09 5.30e-08 4.84e-08 erg/cm2
Peak flux Band 1.13e-01 6.53e-02 1.44e-02 1.18e-03 1.94e-01 1.94e-01 ph/cm2/s
Error 1.84e-02 1.35e-02 7.68e-03 5.60e-03 2.37e-02 3.20e-02 ph/cm2/s
=== Time-averaged spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 2.689 0.296 - - 6.87e-04 1.61e-04 50.083 57
CPL 1.089 1.430 19.0 13.9 7.73e-03 8.22e-02 46.126 56
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 2.706 0.401 - - 8.84e-04 2.83e-04 45.596 57
CPL 1.968 0.000 1.4 13.9 2.73e-03 1.44e-01 44.442 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 48.000 -11.816 36.184
T90 48.000 -11.816 36.184
T50 16.000 4.184 20.184
Peak 1.000 11.684 12.684
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
358.7559 +24.8734 0.0176 20.7 -114.0 0.7473 10.9 TRIG_00151131
------------------------------------------
Foreground time interval of the image:
-11.816 36.184 (delta_t = 48.000 [sec])
Background time interval of the image:
-299.816 -11.816 (delta_t = 288.000 [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 -11.816 sec. to 36.184 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.68950 ( -0.277994 0.313399 )
Norm@50keV : 6.871948E-04 ( -1.597287E-04 1.624109E-04) )
------------------------------------------------------------
Chi-Squared = 50.08321 using 59 PHA bins.
Reduced chi-squared = 0.8786528 for 57 degrees of freedom
Null hypothesis probability = 0.730
Photon flux (15-150 keV) in 48.00 sec: 0.152394 ( -0.019003 0.019008 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.49775e-07 ( -5.42419e-08 5.68315e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -11.816 sec. to 36.184 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.08850 ( -1.95566 0.904276 )
Epeak [keV] : 18.9594 ( -18.9494 8.90897 )
Norm@50keV : 7.734234E-03 ( -7.734234E-03 0.156615 )
------------------------------------------------------------
Chi-Squared = 46.12643 using 59 PHA bins.
Reduced chi-squared = 0.8236862 for 56 degrees of freedom
Null hypothesis probability = 0.824
Photon flux (15-150 keV) in 48.00 sec: 0.147402 ( -0.019091 0.019177 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.13314e-07 ( -4.94107e-08 5.81568e-08 ) ergs/cm2
Band function
Time interval is from -11.816 sec. to 36.184 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.37126 ( -4.24243 0.670419 )
beta : -9.36296 ( -0.637036 19.3630 )
Epeak [keV] : 17.2545 ( -21.3817 5.38385 )
Norm@50keV : 4.650172E-03 ( -1.446706E-03 0.230035 )
------------------------------------------------------------
Chi-Squared = 46.41854 using 59 PHA bins.
Reduced chi-squared = 0.8439735 for 55 degrees of freedom
Null hypothesis probability = 0.788
Photon flux (15-150 keV) in 48.00 sec: 0.147397 ( -0.018148 0.019083 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.08085e-07 ( -4.53662e-08 6.06931e-08 ) ergs/cm2
Peak spectrum fit using the pre-slew DRM
Power-law model
Time interval is from 4.184 sec. to 20.184 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.70592 ( -0.366541 0.436391 )
Norm@50keV : 8.843998E-04 ( -2.803098E-04 2.853117E-04) )
------------------------------------------------------------
Chi-Squared = 45.59565 using 59 PHA bins.
Reduced chi-squared = 0.7999236 for 57 degrees of freedom
Null hypothesis probability = 0.861
Photon flux (15-150 keV) in 16.00 sec: 0.198167 ( -0.031813 0.031838 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.50888e-07 ( -3.10778e-08 3.31381e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 4.184 sec. to 20.184 sec.
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.96828 ( )
Epeak [keV] : 1.42897 ( -13.4169 14.4768 )
Norm@50keV : 2.734342E-03 ( -5.555027E-03 0.283357 )
------------------------------------------------------------
Chi-Squared = 44.44158 using 59 PHA bins.
but latest trial 0.300284 gives Chi-Squared = 0.312305
Reduced chi-squared = 0.7935997 for 56 degrees of freedom
Null hypothesis probability = 0.867
Photon flux (15-150 keV) in 16.00 sec: 0.193700 ( -0.031799 0.03209 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.38344e-07 ( -2.86858e-08 3.66896e-08 ) ergs/cm2
Band function
Time interval is from 4.184 sec. to 20.184 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.38965 ( -8.61035 2.36011 )
beta : -9.23739 ( -0.762607 19.2374 )
Epeak [keV] : 17.2310 ( -17.1310 11.6206 )
Norm@50keV : 5.826260E-03 ( -5.826259E-03 732909. )
------------------------------------------------------------
Chi-Squared = 44.50096 using 59 PHA bins.
Reduced chi-squared = 0.8091084 for 55 degrees of freedom
Null hypothesis probability = 0.843
Photon flux (15-150 keV) in 16.00 sec: 0.193809 ( -0.031286 0.016121 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.50788e-07 ( -2.5908e-08 2.41619e-08 ) ergs/cm2
Plot creation:
Tue Jan 8 17:09:36 EST 2008