batgrbproduct Analysis for Trigger=171931
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 9 19:24:37 EST 2008
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger171931/SDC
======================================================================
Trigger: 00171931 Segment: 000
BAT Trigger Time: 155886381.056 [s; MET]
Trigger Stop: 155886382.08 [s; MET]
UTC: 2005-12-10T05:46:21.168500 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 330.196613815793 Dec: -57.6339823400996 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 8.97
Image Trigger?: NO
Rate S/N Ratio: 15.7797338380595 [ if not an image trigger ]
Image S/N Ratio: 8.97
Flight Position: [ source = BAT ]
RA: 330.196613815793 Dec: -57.6339823400996 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 330.188687494646 Dec: -57.6236362719826 [deg; J2000]
{ 22h 00m 45.3s , -57d 37' 25.1" }
+/- 2.02811921426176 [arcmin] (estimated 90% radius based on SNR)
+/- 1.03524793227579 [arcmin] (formal 1-sigma fit error)
SNR: 11.0767769162709
RA = 22h 0m 45.3s (330.188687 deg.)
Dec = -57d 37' 25" (-57.623636 deg.)
Angular difference between Flight and Ground position is 0.670956 arcmin
Partial Coding Fraction: 0.8984375 [ including projection effects ]
Duration
T90: 1.30400002002716 +/- 0.296971367958634
Measured from: -0.208000004291534
to: 1.09600001573563 [s; relative to TRIGTIME]
T50: 0.564000010490417 +/- 0.28677516664519
Measured from: 0.236000001430511
to: 0.800000011920929 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 0.11599999666214
to: 1.11599999666214 [s; relative to TRIGTIME]
Total Fluence
Measured from: -0.263999998569489
to: 1.19600000977516 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.023242 0.040149 0.043120 0.013895
0.005877 0.006264 0.005768 0.004881 [error]
Peak 0.018252 0.029941 0.039079 0.009841
0.004865 0.005297 0.004874 0.004122 [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 6.76e-09 1.63e-08 3.13e-08 1.46e-07 8.47e-08 2.02e-07 erg/cm2
Error 2.20e-09 3.12e-09 5.34e-09 5.94e-08 1.39e-08 6.17e-08 erg/cm2
Peak flux Power-law 1.56e-01 2.21e-01 2.34e-01 4.56e-01 7.53e-01 1.07e+00 ph/cm2/s
Error 5.53e-02 4.75e-02 3.72e-02 1.65e-01 1.23e-01 1.79e-01 ph/cm2/s
Fluence Cutoff-PL 6.58e-09 1.66e-08 3.20e-08 1.18e-07 8.44e-08 1.53e-07 erg/cm2
Error 2.68e-09 3.34e-09 6.47e-09 8.75e-08 1.42e-08 8.89e-08 erg/cm2
Peak flux Cutoff-PL 1.55e-01 2.21e-01 2.34e-01 4.53e-01 7.53e-01 1.06e+00 ph/cm2/s
Error 5.52e-02 4.76e-02 3.72e-02 1.64e-01 1.23e-01 1.78e-01 ph/cm2/s
Fluence Band 6.46e-09 1.65e-08 3.19e-08 1.19e-07 8.44e-08 1.61e-07 erg/cm2
Error 2.65e-09 3.33e-09 6.48e-09 8.75e-08 1.42e-08 8.82e-08 erg/cm2
Peak flux Band 1.43e-01 2.23e-01 2.42e-01 3.61e-01 7.45e-01 9.68e-01 ph/cm2/s
Error 6.98e-02 5.02e-02 4.87e-02 2.41e-01 1.27e-01 2.69e-01 ph/cm2/s
=== Time-averaged spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.064 0.281 - - 5.49e-03 8.48e-04 62.381 57
CPL 0.901 0.859 395.7 5000.0 6.48e-03 8.20e-03 62.300 0
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 0.922 0.288 - - 6.56e-03 1.06e-03 47.178 57
CPL 0.705 0.970 372.0 5000.0 8.05e-03 1.14e-02 47.014 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: 0.832000 sec.
T50 in the 50-300 keV band: 0.512000 sec.
=== Table of the duration information ==
Value tstart tstop
T100 1.460 -0.264 1.196
T90 1.304 -0.208 1.096
T50 0.564 0.236 0.800
Peak 1.000 0.116 1.116
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
330.1887 -57.6236 0.0174 27.2 -162.9 0.1207 11.1 TRIG_00171931
------------------------------------------
Foreground time interval of the image:
-0.264 1.196 (delta_t = 1.460 [sec])
Background time interval of the image:
-299.056 -0.264 (delta_t = 298.792 [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 -0.264 sec. to 1.196 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.06447 ( -0.286988 0.275552 )
Norm@50keV : 5.488840E-03 ( -8.516083E-04 8.450565E-04) )
------------------------------------------------------------
Chi-Squared = 62.38121 using 59 PHA bins.
Reduced chi-squared = 1.094407 for 57 degrees of freedom
Null hypothesis probability = 0.291
Photon flux (15-150 keV) in 1.460 sec: 0.634652 ( -0.101405 0.102038 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.47458e-08 ( -1.3859e-08 1.39744e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.264 sec. to 1.196 sec.
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.901425 ( -1.28784 0.430788 )
Epeak [keV] : 395.653 ( -395.643 9604.35 )
Norm@50keV : 6.478433E-03 ( -1.705742E-03 1.468547E-02) )
------------------------------------------------------------
Chi-Squared = 62.29963 using 59 PHA bins.
but latest trial 4.772228E-03 gives Chi-Squared = 3.41296
Reduced chi-squared = 1.112493 for 56 degrees of freedom
Null hypothesis probability = 0.262
Photon flux (15-150 keV) in 1.460 sec: 0.634483 ( -0.101394 0.102005 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.44181e-08 ( -1.42032e-08 1.41001e-08 ) ergs/cm2
Band function
Time interval is from -0.264 sec. to 1.196 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.879150 ( -9.12085 5.87850 )
beta : -1.06449 ( -8.37834 0.839923 )
Epeak [keV] : 50.1126 ( -325.342 9674.56 )
Norm@50keV : 9.217734E-03 ( -2.085211E-03 365523. )
------------------------------------------------------------
Chi-Squared = 62.38120 using 59 PHA bins.
Reduced chi-squared = 1.134204 for 55 degrees of freedom
Null hypothesis probability = 0.230
Photon flux (15-150 keV) in 1.460 sec: 0.630226 ( -0.10528 0.104627 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.43772e-08 ( -1.42483e-08 1.41086e-08 ) ergs/cm2
Peak spectrum fit using the pre-slew DRM
Power-law model
Time interval is from 0.116 sec. to 1.116 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.921818 ( -0.297284 0.278415 )
Norm@50keV : 6.558737E-03 ( -1.074939E-03 1.051211E-03) )
------------------------------------------------------------
Chi-Squared = 47.17805 using 59 PHA bins.
Reduced chi-squared = 0.8276851 for 57 degrees of freedom
Null hypothesis probability = 0.820
Photon flux (15-150 keV) in 1.000 sec: 0.753012 ( -0.122678 0.123405 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.29871e-08 ( -1.17639e-08 1.18416e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.116 sec. to 1.116 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.705342 ( -1.45742 0.482076 )
Epeak [keV] : 371.953 ( -371.943 9628.05 )
Norm@50keV : 8.052949E-03 ( -2.497739E-03 2.032614E-02) )
------------------------------------------------------------
Chi-Squared = 47.01409 using 59 PHA bins.
Reduced chi-squared = 0.8395373 for 56 degrees of freedom
Null hypothesis probability = 0.798
Photon flux (15-150 keV) in 1.000 sec: 0.752823 ( -0.122643 0.123387 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.2693e-08 ( -1.21164e-08 1.19261e-08 ) ergs/cm2
Band function
Time interval is from 0.116 sec. to 1.116 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.808912 ( -9.19109 5.80891 )
beta : -0.921823 ( -0.278387 0.297289 )
Epeak [keV] : 29.7914 ( -29.6914 9970.21 )
Norm@50keV : 1.015735E-02 ( -4.612490E-03 2850.45 )
------------------------------------------------------------
Chi-Squared = 47.17805 using 59 PHA bins.
Reduced chi-squared = 0.8577827 for 55 degrees of freedom
Null hypothesis probability = 0.764
Photon flux (15-150 keV) in 1.000 sec: 0.745222 ( -0.127594 0.125834 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.26343e-08 ( -1.20993e-08 1.19551e-08 ) ergs/cm2
Plot creation:
Wed Jan 9 19:37:22 EST 2008