batgrbproduct Analysis for Trigger=280451
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): Fri Dec 14 00:04:22 EST 2007
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger280451/GCN5_download_cron
======================================================================
Trigger: 00280451 Segment: 000
BAT Trigger Time: 201864400 [s; MET]
Trigger Stop: 201864464 [s; MET]
UTC: 2007-05-26T09:26:38.019980 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 301.354610090194 Dec: 31.1882696770797 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 12.77
Image Trigger?: YES
Rate S/N Ratio: 0 [ if not an image trigger ]
Image S/N Ratio: 12.77
Flight Position: [ source = BAT ]
RA: 301.354610090194 Dec: 31.1882696770797 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 301.369222320031 Dec: 31.1606002448959 [deg; J2000]
{ 20h 05m 28.6s , +31d 09' 38.2" }
+/- 1.03352583464069 [arcmin] (estimated 90% radius based on SNR)
+/- 0.388272815635924 [arcmin] (formal 1-sigma fit error)
SNR: 29.0174555033083
RA = 20h 5m 28.6s (301.369222 deg.)
Dec = 31d 9' 38" (31.160600 deg.)
Angular difference between Flight and Ground position is 1.821770 arcmin
Partial Coding Fraction: 0.703125 [ including projection effects ]
Duration
T90: 592 +/- 240.532742053967
Measured from: 20
to: 612 [s; relative to TRIGTIME]
T50: 224 +/- 131.939380019765
Measured from: 132
to: 356 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 363.5
to: 364.5 [s; relative to TRIGTIME]
Total Fluence
Measured from: 4
to: 868 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 5.029119 6.002324 3.758342 0.489605
0.239822 0.241500 0.213246 0.192131 [error]
Peak 0.114922 0.111913 0.088034 -0.009149
0.016014 0.015677 0.013595 0.011719 [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 1.63e-06 2.55e-06 3.00e-06 6.86e-06 9.18e-06 1.40e-05 erg/cm2
Error 1.47e-07 1.34e-07 2.22e-07 1.11e-06 5.11e-07 1.27e-06 erg/cm2
Peak flux Power-law 1.69e-01 1.33e-01 7.08e-02 5.46e-02 3.98e-01 4.28e-01 ph/cm2/s
Error 3.57e-02 1.92e-02 1.63e-02 2.43e-02 5.74e-02 6.22e-02 ph/cm2/s
Fluence Cutoff-PL 1.55e-06 2.60e-06 3.04e-06 4.75e-06 8.99e-06 1.19e-05 erg/cm2
Error 1.81e-07 1.57e-07 2.34e-07 2.44e-06 5.82e-07 2.54e-06 erg/cm2
Peak flux Cutoff-PL 1.56e-01 1.44e-01 7.21e-02 2.52e-02 3.89e-01 3.97e-01 ph/cm2/s
Error 4.09e-02 2.46e-02 1.83e-02 3.27e-02 5.87e-02 8.46e-02 ph/cm2/s
Fluence Band 1.54e-06 2.59e-06 3.03e-06 4.74e-06 8.98e-06 1.22e-05 erg/cm2
Error 1.78e-07 1.57e-07 2.34e-07 2.44e-06 5.84e-07 2.55e-06 erg/cm2
Peak flux Band 1.56e-01 1.44e-01 7.22e-02 2.53e-02 3.89e-01 3.97e-01 ph/cm2/s
Error 4.09e-02 2.46e-02 1.83e-02 3.24e-02 5.87e-02 5.38e-02 ph/cm2/s
=== Time-averaged spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.762 0.100 - - 1.96e-03 1.05e-04 52.910 57
CPL 1.520 0.364 98.2 4971.8 2.60e-03 1.12e-03 51.667 0
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.913 0.267 - - 2.76e-03 4.83e-04 43.038 57
CPL 1.252 1.031 50.3 5000.0 6.41e-03 1.37e-02 41.661 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: 0.000000 sec.
T50 in the 50-300 keV band: 0.000000 sec.
=== Table of the duration information ==
Value tstart tstop
T100 864.000 4.000 868.000
T90 592.000 20.000 612.000
T50 224.000 132.000 356.000
Peak 1.000 363.500 364.500
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
301.3692 +31.1606 0.0066 26.0 -130.2 10.2909 29.0 TRIG_00280451
------------------------------------------
Foreground time interval of the image:
4.000 108.210 (delta_t = 104.210 [sec])
109.000 363.020 (delta_t = 254.020 [sec])
Background time interval of the image:
-60.000 4.000 (delta_t = 64.000 [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
Multiple GTIs in the spectrum
tstart tstop
4.000000 108.210000
109.000000 363.019700
481.000000 603.061800
841.000000 868.000000
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.76198 ( -9.939253E-02 0.100603 )
Norm@50keV : 1.961341E-03 ( -1.056108E-04 1.047915E-04) )
------------------------------------------------------------
Chi-Squared = 52.91016 using 59 PHA bins.
Reduced chi-squared = 0.9282483 for 57 degrees of freedom
Null hypothesis probability = 0.629
Photon flux (15-150 keV) in 507.3 sec: 0.266388 ( -0.014265 0.014315 ) ph/cm2/s
Energy fluence (15-150 keV) : 9.17538e-06 ( -5.09583e-07 5.12221e-07 ) ergs/cm2
Cutoff power-law model
Multiple GTIs in the spectrum
tstart tstop
4.000000 108.210000
109.000000 363.019700
481.000000 603.061800
841.000000 868.000000
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.51990 ( -0.411840 0.315475 )
Epeak [keV] : 98.2428 ( -41.8548 9901.76 )
Norm@50keV : 2.595882E-03 ( -7.099333E-04 1.533137E-03) )
------------------------------------------------------------
Chi-Squared = 51.66709 using 59 PHA bins.
but latest trial 43.3286 gives Chi-Squared = 16.0315
Reduced chi-squared = 0.9226266 for 56 degrees of freedom
Null hypothesis probability = 0.639
Photon flux (15-150 keV) in 507.3 sec: 0.261992 ( -0.015672 0.015685 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.99336e-06 ( -5.86997e-07 5.76952e-07 ) ergs/cm2
Band function
Multiple GTIs in the spectrum
tstart tstop
4.000000 108.210000
109.000000 363.019700
481.000000 603.061800
841.000000 868.000000
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.47816 ( -0.357832 0.372558 )
beta : -8.89562 ( -1.10438 7.20746 )
Epeak [keV] : 91.1613 ( -27.6637 9908.84 )
Norm@50keV : 2.717636E-03 ( -6.676910E-04 1.580735E-03) )
------------------------------------------------------------
Chi-Squared = 51.69723 using 59 PHA bins.
Reduced chi-squared = 0.9399496 for 55 degrees of freedom
Null hypothesis probability = 0.602
Photon flux (15-150 keV) in 507.3 sec: 0.261998 ( -0.015675 0.015692 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.9822e-06 ( -5.85373e-07 5.82938e-07 ) ergs/cm2
Peak spectrum fit using the pre-slew DRM
Power-law model
Time interval is from 356.000 sec. to 363.020 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.91318 ( -0.258121 0.275789 )
Norm@50keV : 2.755970E-03 ( -4.903271E-04 4.757657E-04) )
------------------------------------------------------------
Chi-Squared = 43.03795 using 59 PHA bins.
Reduced chi-squared = 0.7550518 for 57 degrees of freedom
Null hypothesis probability = 0.915
Photon flux (15-150 keV) in 7.020 sec: 0.397745 ( -0.057396 0.05742 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.77944e-07 ( -3.03622e-08 3.10495e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 356.000 sec. to 363.020 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.25236 ( -1.15342 0.907633 )
Epeak [keV] : 50.3335 ( -50.3235 9949.67 )
Norm@50keV : 6.408197E-03 ( -6.408197E-03 2.093685E-02) )
------------------------------------------------------------
Chi-Squared = 41.66106 using 59 PHA bins.
Reduced chi-squared = 0.7439476 for 56 degrees of freedom
Null hypothesis probability = 0.923
Photon flux (15-150 keV) in 7.020 sec: 0.389245 ( -0.058645 0.058685 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.69249e-07 ( -3.15395e-08 3.33576e-08 ) ergs/cm2
Band function
Time interval is from 356.000 sec. to 363.020 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.26495 ( -8.73505 1.11665 )
beta : -8.93667 ( -1.06333 7.20499 )
Epeak [keV] : 50.4105 ( -50.3106 9949.59 )
Norm@50keV : 6.315805E-03 ( -3.153549E-03 2.102920E-02) )
------------------------------------------------------------
Chi-Squared = 41.66100 using 59 PHA bins.
Reduced chi-squared = 0.7574728 for 55 degrees of freedom
Null hypothesis probability = 0.908
Photon flux (15-150 keV) in 7.020 sec: 0.389337 ( -0.05876 0.058603 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.69107e-07 ( -3.1571e-08 3.3312e-08 ) ergs/cm2
Plot creation:
Fri Dec 14 00:16:09 EST 2007