batgrbproduct Analysis for Trigger=280450
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): Thu Dec 13 23:53:07 EST 2007
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger280450/GCN5_download_cron
======================================================================
Trigger: 00280450 Segment: 000
BAT Trigger Time: 201863064 [s; MET]
Trigger Stop: 201863192 [s; MET]
UTC: 2007-05-26T09:04:22.020020 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 291.970572404101 Dec: 6.68704249799701 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 13.28
Image Trigger?: YES
Rate S/N Ratio: 0 [ if not an image trigger ]
Image S/N Ratio: 13.28
Flight Position: [ source = BAT ]
RA: 291.970572404101 Dec: 6.68704249799701 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 291.970286578674 Dec: 6.7203664202251 [deg; J2000]
{ 19h 27m 52.9s , +06d 43' 13.3" }
+/- 1.82679524119517 [arcmin] (estimated 90% radius based on SNR)
+/- 0.693400326042521 [arcmin] (formal 1-sigma fit error)
SNR: 12.8610286672529
RA = 19h 27m 52.9s (291.970287 deg.)
Dec = 6d 43' 13" (6.720366 deg.)
Angular difference between Flight and Ground position is 1.999508 arcmin
Partial Coding Fraction: 0.546875 [ including projection effects ]
Duration
T90: 128 +/-
Measured from: 0
to: 128 [s; relative to TRIGTIME]
T50: 128 +/-
Measured from: 0
to: 128 [s; relative to TRIGTIME]
WARNING: battblocks failed. Used TDRSS fore/background intervals
Fluence
Peak Flux (peak 128 second)
Measured from: 0
to: 128 [s; relative to TRIGTIME]
Total Fluence
Measured from: 0
to: 128 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 1.017353 0.811215 0.104010 0.034024
0.077697 0.076889 0.066722 0.057720 [error]
Peak 1.017353 0.811215 0.104010 0.034024
0.077697 0.076889 0.066722 0.057720 [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 3.46e-07 3.10e-07 1.91e-07 1.79e-07 9.22e-07 1.02e-06 erg/cm2
Error 4.83e-08 4.17e-08 5.42e-08 9.46e-08 1.28e-07 1.78e-07 erg/cm2
Peak flux Power-law 8.94e-02 4.48e-02 1.38e-02 5.42e-03 1.51e-01 1.53e-01 ph/cm2/s
Error 1.28e-02 5.78e-03 3.79e-03 2.69e-03 1.69e-02 1.71e-02 ph/cm2/s
Fluence Cutoff-PL 0.00e+00 0.00e+00 0.00e+00 0.00e+00 0.00e+00 0.00e+00 erg/cm2
Error 0.00e+00 0.00e+00 0.00e+00 0.00e+00 0.00e+00 0.00e+00 erg/cm2
Peak flux Cutoff-PL 0.00e+00 0.00e+00 0.00e+00 0.00e+00 0.00e+00 0.00e+00 ph/cm2/s
Error 0.00e+00 0.00e+00 0.00e+00 0.00e+00 0.00e+00 0.00e+00 ph/cm2/s
Fluence Band 3.31e-07 3.36e-07 1.48e-07 5.89e-08 8.51e-07 8.78e-07 erg/cm2
Error 5.20e-08 4.76e-08 4.26e-08 7.79e-08 1.41e-07 2.04e-07 erg/cm2
Peak flux Band 8.55e-02 4.89e-02 1.11e-02 1.99e-03 1.47e-01 1.48e-01 ph/cm2/s
Error 1.36e-02 7.15e-03 2.61e-03 3.30e-03 1.72e-02 1.79e-02 ph/cm2/s
=== Time-averaged spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 2.698 0.273 - - 6.78e-04 1.41e-04 66.367 57
CPL 1.459 0.000 14.4 0.0 4.42e-03 0.00e+00 64.267 0
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 2.698 0.273 - - 6.78e-04 1.41e-04 66.367 57
CPL 1.459 0.000 14.4 0.0 4.42e-03 0.00e+00 64.267 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 128.000 0.000 128.000
T90 128.000 0.000 128.000
T50 128.000 0.000 128.000
Peak 128.000 0.000 128.000
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
291.9703 +6.7204 0.0149 26.2 56.6 2.0927 12.9 TRIG_00280450
------------------------------------------
Foreground time interval of the image:
0.000 128.000 (delta_t = 128.000 [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 128.000 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.69839 ( -0.259236 0.285887 )
Norm@50keV : 6.776280E-04 ( -1.403257E-04 1.416123E-04) )
------------------------------------------------------------
Chi-Squared = 66.36710 using 59 PHA bins.
Reduced chi-squared = 1.164335 for 57 degrees of freedom
Null hypothesis probability = 0.185
Photon flux (15-150 keV) in 128.0 sec: 0.151085 ( -0.016854 0.016855 ) ph/cm2/s
Energy fluence (15-150 keV) : 9.22348e-07 ( -1.25094e-07 1.30145e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.000 sec. to 128.000 sec.
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.45917 ( )
Epeak [keV] : 14.4004 ( )
Norm@50keV : 4.422129E-03 ( )
------------------------------------------------------------
Chi-Squared = 64.26704 using 59 PHA bins.
but latest trial -2.280474E-04 gives Chi-Squared = 5.44979
Reduced chi-squared = 1.147626 for 56 degrees of freedom
Null hypothesis probability = 0.210
Photon flux (15-150 keV) in 128.0 sec: ( ) ph/cm2/s
Energy fluence (15-150 keV) : 0 ( 0 0 ) ergs/cm2
Band function
Time interval is from 0.000 sec. to 128.000 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.47924 ( -8.52076 0.312009 )
beta : -6.74331 ( -6.13669 1.19495 )
Epeak [keV] : 14.1020 ( -14.0017 6.87315 )
Norm@50keV : 4.289355E-03 ( -4.285416E-03 0.133926 )
------------------------------------------------------------
Chi-Squared = 64.26584 using 59 PHA bins.
Reduced chi-squared = 1.168470 for 55 degrees of freedom
Null hypothesis probability = 0.184
Photon flux (15-150 keV) in 128.0 sec: 0.146873 ( -0.017273 0.017074 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.51212e-07 ( -1.4566e-07 1.36813e-07 ) ergs/cm2
Peak spectrum fit using the pre-slew DRM
Power-law model
Time interval is from 0.000 sec. to 128.000 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.69839 ( -0.259236 0.285887 )
Norm@50keV : 6.776280E-04 ( -1.403257E-04 1.416123E-04) )
------------------------------------------------------------
Chi-Squared = 66.36710 using 59 PHA bins.
Reduced chi-squared = 1.164335 for 57 degrees of freedom
Null hypothesis probability = 0.185
Photon flux (15-150 keV) in 128.0 sec: 0.151085 ( -0.016854 0.016855 ) ph/cm2/s
Energy fluence (15-150 keV) : 9.22348e-07 ( -1.25094e-07 1.30145e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.000 sec. to 128.000 sec.
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.45917 ( )
Epeak [keV] : 14.4004 ( )
Norm@50keV : 4.422129E-03 ( )
------------------------------------------------------------
Chi-Squared = 64.26704 using 59 PHA bins.
but latest trial -2.280474E-04 gives Chi-Squared = 5.44979
Reduced chi-squared = 1.147626 for 56 degrees of freedom
Null hypothesis probability = 0.210
Photon flux (15-150 keV) in 128.0 sec: ( ) ph/cm2/s
Energy fluence (15-150 keV) : 0 ( 0 0 ) ergs/cm2
Band function
Time interval is from 0.000 sec. to 128.000 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.47924 ( -8.52076 0.312009 )
beta : -6.74331 ( -6.13669 1.19495 )
Epeak [keV] : 14.1020 ( -14.0017 6.87315 )
Norm@50keV : 4.289355E-03 ( -4.285416E-03 0.133926 )
------------------------------------------------------------
Chi-Squared = 64.26584 using 59 PHA bins.
Reduced chi-squared = 1.168470 for 55 degrees of freedom
Null hypothesis probability = 0.184
Photon flux (15-150 keV) in 128.0 sec: 0.146873 ( -0.017273 0.017074 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.51212e-07 ( -1.4566e-07 1.36813e-07 ) ergs/cm2
Plot creation:
Fri Dec 14 00:03:08 EST 2007