batgrbproduct Analysis for Trigger=287409
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 09:58:38 EST 2007
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger287409/SDC
======================================================================
Trigger: 00287409 Segment: 000
BAT Trigger Time: 208451960.036 [s; MET]
Trigger Stop: 208451960.1 [s; MET]
UTC: 2007-08-10T15:19:17.889760 [includes UTCF correction]
Where From?: (*SHORT BURST*) TDRSS scaled map message
BAT
RA: 8.94039483391689 Dec: 8.83544274479816 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 6.79
Image Trigger?: NO
Rate S/N Ratio: 15.3948043183407 [ if not an image trigger ]
Image S/N Ratio: 6.79
Flight Position: [ source = BAT ]
RA: 8.94039483391689 Dec: 8.83544274479816 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 8.9519155759586 Dec: 8.81957258505406 [deg; J2000]
{ 00h 35m 48.5s , +08d 49' 10.5" }
+/- 2.48048159374677 [arcmin] (estimated 90% radius based on SNR)
+/- 1.14835423015982 [arcmin] (formal 1-sigma fit error)
SNR: 8.30798130074313
RA = 0h 35m 48.5s (8.951916 deg.)
Dec = 8d 49' 10" (8.819573 deg.)
Angular difference between Flight and Ground position is 1.171866 arcmin
Partial Coding Fraction: 1.03125 [ including projection effects ]
Duration
T90: 0.0760000050067902 +/- 0.026832803468234
Measured from: -0.00800001621246338
to: 0.0679999887943268 [s; relative to TRIGTIME]
T50: 0.0280000269412994 +/- 0.019999998807908
Measured from: 0.015999972820282
to: 0.0439999997615814 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: -0.464000016450882
to: 0.535999983549118 [s; relative to TRIGTIME]
Total Fluence
Measured from: -0.00800001621246338
to: 0.0759999752044678 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.006958 0.008517 0.007204 0.001417
0.001596 0.001698 0.001690 0.001210 [error]
Peak 0.006831 0.008133 0.007417 0.001740
0.001633 0.001734 0.001707 0.001227 [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 1.50e-09 2.98e-09 4.61e-09 1.56e-08 1.29e-08 2.40e-08 erg/cm2
Error 5.39e-10 7.14e-10 1.32e-09 8.97e-09 3.31e-09 0.00e+00 erg/cm2
Peak flux Power-law 5.30e-01 5.80e-01 4.52e-01 5.78e-01 1.78e+00 2.14e+00 ph/cm2/s
Error 2.03e-01 1.48e-01 1.29e-01 3.17e-01 4.28e-01 5.29e-01 ph/cm2/s
Fluence Cutoff-PL 1.07e-09 3.52e-09 5.59e-09 3.60e-09 1.26e-08 1.43e-08 erg/cm2
Error 6.76e-10 9.70e-10 1.83e-09 7.88e-09 3.53e-09 8.25e-09 erg/cm2
Peak flux Cutoff-PL 3.75e-01 6.54e-01 5.56e-01 2.13e-01 1.74e+00 1.80e+00 ph/cm2/s
Error 2.55e-01 1.87e-01 1.85e-01 3.40e-01 4.38e-01 5.25e-01 ph/cm2/s
Fluence Band 1.09e-09 3.50e-09 5.59e-09 3.60e-09 1.26e-08 1.44e-08 erg/cm2
Error 5.49e-10 9.65e-10 1.58e-09 8.29e-09 3.48e-09 8.22e-09 erg/cm2
Peak flux Band 3.74e-01 6.54e-01 5.55e-01 2.14e-01 1.74e+00 1.80e+00 ph/cm2/s
Error 2.56e-01 1.88e-01 1.84e-01 3.42e-01 4.31e-01 4.87e-01 ph/cm2/s
=== Time-averaged spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.375 0.352 - - 1.58e-02 3.69e-03 62.793 57
CPL -0.329 2.174 75.2 256.4 9.99e-02 6.70e-01 59.781 0
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.361 0.367 - - 1.47e-02 3.56e-03 59.577 57
CPL -0.167 2.235 79.5 4972.5 7.54e-02 5.81e-01 57.123 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 0.084 -0.008 0.076
T90 0.076 -0.008 0.068
T50 0.028 0.016 0.044
Peak 1.000 -0.464 0.536
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
8.9519 +8.8196 0.0232 7.9 -151.4 0.0250 8.3 TRIG_00287409
------------------------------------------
Foreground time interval of the image:
0.028 0.112 (delta_t = 0.084 [sec])
Background time interval of the image:
-147.195 0.028 (delta_t = 147.223 [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 0.028 sec. to 0.112 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.37484 ( -0.342036 0.362517 )
Norm@50keV : 1.577032E-02 ( -3.698431E-03 3.671914E-03) )
------------------------------------------------------------
Chi-Squared = 62.79299 using 59 PHA bins.
Reduced chi-squared = 1.101631 for 57 degrees of freedom
Null hypothesis probability = 0.279
Photon flux (15-150 keV) in 8.4000E-02 sec: 1.90987 ( -0.44167 0.4421 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.28754e-08 ( -3.29851e-09 3.3227e-09 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.028 sec. to 0.112 sec.
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.328728 ( -2.67127 1.67631 )
Epeak [keV] : 75.2132 ( -21.5316 491.258 )
Norm@50keV : 9.987921E-02 ( -9.987921E-02 1.24080 )
------------------------------------------------------------
Chi-Squared = 59.78120 using 59 PHA bins.
but latest trial 1.34017 gives Chi-Squared = 2.58645
Reduced chi-squared = 1.067521 for 56 degrees of freedom
Null hypothesis probability = 0.340
Photon flux (15-150 keV) in 8.4000E-02 sec: 1.86221 ( -0.46016 0.45151 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.25932e-08 ( -3.49902e-09 3.55303e-09 ) ergs/cm2
Band function
Time interval is from 0.028 sec. to 0.112 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : 0.326453 ( -1.67469 1.97888 )
beta : -9.35228 ( -0.647717 8.00205 )
Epeak [keV] : 75.2054 ( -20.3955 486.328 )
Norm@50keV : 9.969724E-02 ( -9.969724E-02 6.64578 )
------------------------------------------------------------
Chi-Squared = 59.78131 using 59 PHA bins.
Reduced chi-squared = 1.086933 for 55 degrees of freedom
Null hypothesis probability = 0.306
Photon flux (15-150 keV) in 8.4000E-02 sec: 1.86362 ( -0.44635 0.44936 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.26088e-08 ( -3.42392e-09 3.53287e-09 ) ergs/cm2
Peak spectrum fit using the pre-slew DRM
Power-law model
Time interval is from 0.028 sec. to 0.116 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.36079 ( -0.356995 0.377254 )
Norm@50keV : 1.472812E-02 ( -3.565609E-03 3.545455E-03) )
------------------------------------------------------------
Chi-Squared = 59.57686 using 59 PHA bins.
Reduced chi-squared = 1.045208 for 57 degrees of freedom
Null hypothesis probability = 0.382
Photon flux (15-150 keV) in 8.8000E-02 sec: 1.77831 ( -0.42802 0.42857 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.26291e-08 ( -3.32631e-09 3.36301e-09 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.028 sec. to 0.116 sec.
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.166646 ( -2.83335 1.63640 )
Epeak [keV] : 79.5500 ( -24.5512 9920.45 )
Norm@50keV : 7.538820E-02 ( -7.538820E-02 1.08646 )
------------------------------------------------------------
Chi-Squared = 57.12331 using 59 PHA bins.
but latest trial 1.16185 gives Chi-Squared = 2.81279
Reduced chi-squared = 1.020059 for 56 degrees of freedom
Null hypothesis probability = 0.433
Photon flux (15-150 keV) in 8.8000E-02 sec: 1.74016 ( -0.44097 0.43571 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.25118e-08 ( -3.52862e-09 3.53778e-09 ) ergs/cm2
Band function
Time interval is from 0.028 sec. to 0.116 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : 0.162859 ( -1.63183 3.44202 )
beta : -8.84759 ( -1.15241 7.55892 )
Epeak [keV] : 79.5882 ( -23.1717 9920.41 )
Norm@50keV : 7.511529E-02 ( -7.511529E-02 1.744348E-02) )
------------------------------------------------------------
Chi-Squared = 57.12343 using 59 PHA bins.
Reduced chi-squared = 1.038608 for 55 degrees of freedom
Null hypothesis probability = 0.396
Photon flux (15-150 keV) in 8.8000E-02 sec: 1.74049 ( -0.42999 0.43199 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.25044e-08 ( -1.85566e-09 1.85557e-09 ) ergs/cm2
Plot creation:
Fri Dec 14 10:18:12 EST 2007