batgrbproduct Analysis for Trigger=228720
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 2 04:17:49 EST 2008
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger228720/GCN5_download_cron
======================================================================
Trigger: 00228720 Segment: 000
BAT Trigger Time: 179479296 [s; MET]
Trigger Stop: 179479360 [s; MET]
UTC: 2006-09-09T07:21:34.567020 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 28.4474772589984 Dec: -36.360063694932 [deg; J2000]
Catalogged Source?: YES
Point Source?: YES
GRB Indicated?: NO [ by BAT flight software ]
Image S/N Ratio: 5.54
Image Trigger?: YES
Rate S/N Ratio: 0 [ if not an image trigger ]
Image S/N Ratio: 5.54
Flight Position: [ source = BAT ]
RA: 28.4474772589984 Dec: -36.360063694932 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 28.4127697905237 Dec: -36.3001650098882 [deg; J2000]
{ 01h 53m 39.1s , -36d 18' 00.6" }
+/- 4.31931435376836 [arcmin] (estimated 90% radius based on SNR)
+/- 3.05531663277572 [arcmin] (formal 1-sigma fit error)
SNR: 3.76168940147957
RA = 1h 53m 39.1s (28.412770 deg.)
Dec = -36d 18' 1" (-36.300165 deg.)
Angular difference between Flight and Ground position is 3.966207 arcmin
Partial Coding Fraction: 0.59375 [ including projection effects ]
Duration
T90: 64 +/-
Measured from: 0
to: 64 [s; relative to TRIGTIME]
T50: 64 +/-
Measured from: 0
to: 64 [s; relative to TRIGTIME]
WARNING: battblocks failed. Used TDRSS fore/background intervals
Fluence
Peak Flux (peak 64 second)
Measured from: 0
to: 64 [s; relative to TRIGTIME]
Total Fluence
Measured from: 0
to: 64 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.106071 0.083722 -0.031511 -0.010256
0.037161 0.037844 0.034072 0.031387 [error]
Peak 0.106071 0.083722 -0.031511 -0.010256
0.037161 0.037844 0.034072 0.031387 [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 3.99e-08 1.85e-08 5.19e-09 1.82e-09 6.47e-08 6.57e-08 erg/cm2
Error 1.87e-08 2.00e-08 1.31e-08 1.51e-08 4.71e-08 5.38e-08 erg/cm2
Peak flux Power-law 4.09e-02 1.08e-02 1.52e-03 2.40e-04 5.34e-02 5.35e-02 ph/cm2/s
Error 1.93e-02 1.12e-02 3.64e-03 1.72e-03 2.84e-02 2.86e-02 ph/cm2/s
Fluence Cutoff-PL 3.99e-08 1.85e-08 5.19e-09 1.81e-09 6.47e-08 6.53e-08 erg/cm2
Error 1.88e-08 2.00e-08 1.31e-08 1.50e-08 4.71e-08 5.37e-08 erg/cm2
Peak flux Cutoff-PL 4.09e-02 1.08e-02 1.51e-03 2.39e-04 5.34e-02 5.34e-02 ph/cm2/s
Error 1.93e-02 1.12e-02 3.64e-03 1.71e-03 2.84e-02 2.86e-02 ph/cm2/s
Fluence Band 3.95e-08 1.91e-08 5.61e-09 2.07e-09 6.55e-08 6.35e-08 erg/cm2
Error 1.85e-08 1.40e-08 1.11e-08 6.42e-09 5.04e-06 0.00e+00 erg/cm2
Peak flux Band 4.15e-02 1.12e-02 9.81e-04 3.22e-05 5.37e-02 5.37e-02 ph/cm2/s
Error 1.96e-02 8.20e-03 3.81e-03 1.11e-03 2.79e-02 2.65e-02 ph/cm2/s
=== Time-averaged spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 3.834 2.299 - - 1.00e-04 1.72e-04 61.179 57
CPL 4.895 27.763 0.0 27.2 6.12e+01 0.00e+00 0.000 0
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 3.834 2.299 - - 1.00e-04 1.72e-04 61.179 57
CPL 1.576 3.760 4.9 30.0 4.88e-03 0.00e+00 61.224 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 64.000 0.000 64.000
T90 64.000 0.000 64.000
T50 64.000 0.000 64.000
Peak 64.000 0.000 64.000
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
28.4128 -36.3002 0.0513 36.7 2.4 0.2744 3.8 TRIG_00228720
------------------------------------------
Foreground time interval of the image:
0.000 33.054 (delta_t = 33.054 [sec])
Background time interval of the image:
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 0.000 sec. to 33.054 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 3.83377 ( -1.41757 3.18068 )
Norm@50keV : 9.997570E-05 ( -9.997570E-05 2.430498E-04) )
------------------------------------------------------------
Chi-Squared = 61.17879 using 59 PHA bins.
Reduced chi-squared = 1.073312 for 57 degrees of freedom
Null hypothesis probability = 0.328
Photon flux (15-150 keV) in 33.05 sec: 5.340408E-02 ( -0.0283099 0.0285648 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.46636e-08 ( -3.98679e-08 5.4276e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.000 sec. to 33.054 sec.
Norm@50keV : 4.875543E-03 ( -1.289663E-03 54.3095 )
------------------------------------------------------------
Chi-Squared = 61.22365 using 59 PHA bins.
but latest trial -2.44286 gives Chi-Squared = 0.762581
but latest trial -5.92443 gives Chi-Squared = 5.37498
but latest trial 89.7531 gives Chi-Squared = 4.38016
but latest trial 1.289691E-03 gives Chi-Squared = 3.25078
but latest trial 40.1332 gives Chi-Squared = 0.907162
Reduced chi-squared = 1.093279 for 56 degrees of freedom
Null hypothesis probability = 0.294
Photon flux (15-150 keV) in 33.05 sec: 5.337682E-02 ( -0.0283107 0.0285571 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.46997e-08 ( -3.99204e-08 5.42301e-08 ) ergs/cm2
Band function
Time interval is from 0.000 sec. to 33.054 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -7.96030 ( -2.03970 10.6017 )
beta : -3.83372 ( -3.17832 1.41773 )
Epeak [keV] : 23.7595 ( -23.6595 9976.24 )
Norm@50keV : 1.358877E-02 ( -1.358877E-02 3.303366E-02) )
------------------------------------------------------------
Chi-Squared = 61.17879 using 59 PHA bins.
Reduced chi-squared = 1.112342 for 55 degrees of freedom
Null hypothesis probability = 0.264
Photon flux (15-150 keV) in 33.05 sec: 5.370998E-02 ( -0.0277215 0.0280207 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.55193e-08 ( -3.66412e-08 1.00396e-05 ) ergs/cm2
Peak spectrum fit using the pre-slew DRM
Power-law model
Time interval is from 0.000 sec. to 33.054 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 3.83377 ( -1.41757 3.18068 )
Norm@50keV : 9.997570E-05 ( -9.997570E-05 2.430498E-04) )
------------------------------------------------------------
Chi-Squared = 61.17879 using 59 PHA bins.
Reduced chi-squared = 1.073312 for 57 degrees of freedom
Null hypothesis probability = 0.328
Photon flux (15-150 keV) in 33.05 sec: 5.340408E-02 ( -0.0283099 0.0285648 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.46636e-08 ( -3.98679e-08 5.4276e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.000 sec. to 33.054 sec.
Parameters : value lower 90% higher 90%
Photon index: 1.57588 ( -3.86219 3.65878 )
Epeak [keV] : 4.89525 ( -4.88524 55.0585 )
Norm@50keV : 4.875543E-03 ( )
------------------------------------------------------------
Chi-Squared = 61.22365 using 59 PHA bins.
but latest trial -2.44286 gives Chi-Squared = 0.762581
but latest trial 95.0114 gives Chi-Squared = 4.28334
Reduced chi-squared = 1.093279 for 56 degrees of freedom
Null hypothesis probability = 0.294
Photon flux (15-150 keV) in 33.05 sec: 5.337682E-02 ( -0.0283107 0.0285571 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.46997e-08 ( -3.99204e-08 5.42301e-08 ) ergs/cm2
Band function
Time interval is from 0.000 sec. to 33.054 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -7.96030 ( -2.03970 10.6017 )
beta : -3.83372 ( -3.17832 1.41773 )
Epeak [keV] : 23.7595 ( -23.6595 9976.24 )
Norm@50keV : 1.358877E-02 ( -1.358877E-02 3.303366E-02) )
------------------------------------------------------------
Chi-Squared = 61.17879 using 59 PHA bins.
Reduced chi-squared = 1.112342 for 55 degrees of freedom
Null hypothesis probability = 0.264
Photon flux (15-150 keV) in 33.05 sec: 5.370998E-02 ( -0.0277215 0.0280207 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.55193e-08 ( -3.66412e-08 1.00396e-05 ) ergs/cm2
Plot creation:
Wed Jan 2 04:22:18 EST 2008