batgrbproduct Analysis for Trigger=287421
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 10:19:04 EST 2007
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger287421/GCN5_download_cron
======================================================================
Trigger: 00287421 Segment: 000
BAT Trigger Time: 208468448 [s; MET]
Trigger Stop: 208468512 [s; MET]
UTC: 2007-08-10T19:54:05.853340 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 244.641782400707 Dec: -15.4998067324644 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 12.54
Image Trigger?: YES
Rate S/N Ratio: 0 [ if not an image trigger ]
Image S/N Ratio: 12.54
Flight Position: [ source = BAT ]
RA: 244.641782400707 Dec: -15.4998067324644 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 244.587058604107 Dec: -15.4324178747648 [deg; J2000]
{ 16h 18m 20.9s , -15d 25' 56.7" }
+/- 3.58870455199229 [arcmin] (estimated 90% radius based on SNR)
+/- 3.3419000700596 [arcmin] (formal 1-sigma fit error)
SNR: 4.90173952238935
RA = 16h 18m 20.9s (244.587059 deg.)
Dec = -15d 25' 57" (-15.432418 deg.)
Angular difference between Flight and Ground position is 5.134469 arcmin
Partial Coding Fraction: 0.3242188 [ including projection effects ]
Duration
T90: 149.951999992132 +/- 24.7973980845958
Measured from: -13.0719999969006
to: 136.879999995232 [s; relative to TRIGTIME]
T50: 87.8680000007153 +/- 27.9551101039688
Measured from: 17.2240000069141
to: 105.092000007629 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: -3.06000000238419
to: -2.06000000238419 [s; relative to TRIGTIME]
Total Fluence
Measured from: -23.0519999861717
to: 143.351999998093 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 3.660292 0.343170 -0.016650 -0.026176
0.111377 0.100074 0.084981 0.073706 [error]
Peak 0.034135 0.021318 0.006858 0.011446
0.009658 0.008886 0.007451 0.006846 [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 1.28e-06 1.84e-07 1.20e-08 8.30e-10 1.47e-06 1.47e-06 erg/cm2
Error 1.52e-07 4.67e-08 7.40e-09 1.06e-09 1.61e-07 1.61e-07 erg/cm2
Peak flux Power-law 4.33e-01 1.56e-01 3.19e-02 7.78e-03 6.25e-01 6.28e-01 ph/cm2/s
Error 1.84e-01 1.25e-01 4.74e-02 2.77e-02 2.36e-01 2.39e-01 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 3.52e-07 1.78e-07 1.20e-08 7.94e-10 1.47e-06 1.16e-06 erg/cm2
Error 1.68e-07 0.00e+00 0.00e+00 0.00e+00 0.00e+00 0.00e+00 erg/cm2
Peak flux Band 4.33e-01 1.55e-01 3.19e-02 7.72e-03 6.25e-01 6.28e-01 ph/cm2/s
Error 1.84e-01 1.25e-01 4.74e-02 2.75e-02 2.36e-01 2.39e-01 ph/cm2/s
=== Time-averaged spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 5.897 0.515 - - 7.89e-05 3.80e-05 67.765 57
CPL 1.642 0.000 1.7 0.0 2.74e-01 0.00e+00 66.362 56
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 3.244 1.739 - - 1.89e-03 2.08e-03 63.272 57
CPL 1.912 0.000 2.0 0.0 1.59e-02 0.00e+00 64.186 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 166.404 -23.052 143.352
T90 149.952 -13.072 136.880
T50 87.868 17.224 105.092
Peak 1.000 -3.060 -2.060
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
244.5871 -15.4324 0.0393 33.6 -103.9 1.3694 4.9 TRIG_00287421
------------------------------------------
Foreground time interval of the image:
-23.052 71.701 (delta_t = 94.753 [sec])
Background time interval of the image:
-65.799 -23.052 (delta_t = 42.747 [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 -23.052 sec. to 143.352 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 5.89685 ( -0.461659 0.568861 )
Norm@50keV : 7.889200E-05 ( -3.390352E-05 4.219192E-05) )
------------------------------------------------------------
Chi-Squared = 67.76504 using 59 PHA bins.
Reduced chi-squared = 1.188860 for 57 degrees of freedom
Null hypothesis probability = 0.156
Photon flux (15-150 keV) in 166.4 sec: 0.293625 ( -0.03344 0.033487 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.47196e-06 ( -1.60757e-07 1.60832e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -23.052 sec. to 143.352 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.64215 ( )
Epeak [keV] : 1.71873 ( )
Norm@50keV : 0.274448 ( )
------------------------------------------------------------
Chi-Squared = 66.36182 using 59 PHA bins.
Reduced chi-squared = 1.185032 for 56 degrees of freedom
Null hypothesis probability = 0.162
Photon flux (15-150 keV) in 166.4 sec: ( ) ph/cm2/s
Energy fluence (15-150 keV) : 0 ( 0 0 ) ergs/cm2
Band function
Time interval is from -23.052 sec. to 143.352 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -9.28412 ( -0.715876 7.42392 )
beta : -5.93944 ( -0.524091 0.502499 )
Epeak [keV] : 258.539 ( -258.439 9741.46 )
Norm@50keV : 1.030484E-02 ( -4.178405E-03 6.126389E-03) )
------------------------------------------------------------
Chi-Squared = 67.74624 using 59 PHA bins.
Reduced chi-squared = 1.231750 for 55 degrees of freedom
Null hypothesis probability = 0.116
Photon flux (15-150 keV) in 166.4 sec: 0.292811 ( -0.016957 0.033343 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.47099e-06 ( -1.60083e-07 1.75712e-07 ) ergs/cm2
Peak spectrum fit using the pre-slew DRM
Power-law model
Time interval is from -3.060 sec. to -2.060 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 3.24360 ( -1.07183 2.40607 )
Norm@50keV : 1.885218E-03 ( -1.885218E-03 2.277588E-03) )
------------------------------------------------------------
Chi-Squared = 63.27230 using 59 PHA bins.
Reduced chi-squared = 1.110040 for 57 degrees of freedom
Null hypothesis probability = 0.265
Photon flux (15-150 keV) in 1.000 sec: 0.625239 ( -0.236689 0.234808 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.54805e-08 ( -1.27362e-08 1.5217e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -3.060 sec. to -2.060 sec.
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.91204 ( )
Epeak [keV] : 1.95142 ( )
Norm@50keV : 1.587019E-02 ( )
------------------------------------------------------------
Chi-Squared = 64.18623 using 59 PHA bins.
but latest trial 0.310452 gives Chi-Squared = 0.815048
Reduced chi-squared = 1.146183 for 56 degrees of freedom
Null hypothesis probability = 0.212
Photon flux (15-150 keV) in 1.000 sec: ( ) ph/cm2/s
Energy fluence (15-150 keV) : 0 ( 0 0 ) ergs/cm2
Band function
Time interval is from -3.060 sec. to -2.060 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.83293 ( -5.34752 9.65248 )
beta : -9.36256 ( -2.36011 1.11529 )
Epeak [keV] : 12.5886 ( -12.4886 9987.41 )
Norm@50keV : 6.948559E-03 ( -0.248727 0.317144 )
------------------------------------------------------------
Chi-Squared = 65.50558 using 59 PHA bins.
Reduced chi-squared = 1.191011 for 55 degrees of freedom
Null hypothesis probability = 0.157
Photon flux (15-150 keV) in 1.000 sec: 0.624924 ( -0.236752 0.234716 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.52296e-08 ( -9.2182e-09 2.29377e-08 ) ergs/cm2
Plot creation:
Fri Dec 14 10:29:44 EST 2007