batgrbproduct Analysis for Trigger=228316
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 03:23:18 EST 2008
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger228316/GCN5_download_cron
======================================================================
Trigger: 00228316 Segment: 000
BAT Trigger Time: 179224368 [s; MET]
Trigger Stop: 179224432 [s; MET]
UTC: 2006-09-06T08:32:46.573080 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 40.7485000090217 Dec: 30.3494020585399 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 7.96
Image Trigger?: YES
Rate S/N Ratio: 0 [ if not an image trigger ]
Image S/N Ratio: 7.96
Flight Position: [ source = BAT ]
RA: 40.7485000090217 Dec: 30.3494020585399 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 40.7097134711121 Dec: 30.3662799831574 [deg; J2000]
{ 02h 42m 50.3s , +30d 21' 58.6" }
+/- 2.58427500624567 [arcmin] (estimated 90% radius based on SNR)
+/- 1.33840594553739 [arcmin] (formal 1-sigma fit error)
SNR: 7.83543397188559
RA = 2h 42m 50.3s (40.709713 deg.)
Dec = 30d 21' 59" (30.366280 deg.)
Angular difference between Flight and Ground position is 2.248996 arcmin
Partial Coding Fraction: 0.453125 [ including projection effects ]
Duration
T90: 43.5119999945164 +/- 8.16698720444148
Measured from: -39.9399999976158
to: 3.57199999690056 [s; relative to TRIGTIME]
T50: 14.4679999947548 +/- 2.49773176413273
Measured from: -32.4799999892712
to: -18.0119999945164 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: -24.863999992609
to: -23.863999992609 [s; relative to TRIGTIME]
Total Fluence
Measured from: -41.7960000038147
to: 5.86399999260902 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 1.339938 1.432484 0.772260 0.163792
0.065892 0.067056 0.058261 0.048776 [error]
Peak 0.072546 0.082895 0.046526 0.006012
0.009708 0.010367 0.008572 0.006892 [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 4.67e-07 6.46e-07 6.59e-07 1.23e-06 2.16e-06 3.00e-06 erg/cm2
Error 4.32e-08 3.70e-08 5.88e-08 2.26e-07 1.36e-07 2.80e-07 erg/cm2
Peak flux Power-law 8.53e-01 6.33e-01 3.13e-01 2.20e-01 1.90e+00 2.02e+00 ph/cm2/s
Error 1.68e-01 8.85e-02 7.05e-02 9.29e-02 2.67e-01 2.83e-01 ph/cm2/s
Fluence Cutoff-PL 4.39e-07 6.76e-07 6.62e-07 6.20e-07 2.08e-06 2.46e-06 erg/cm2
Error 5.04e-08 4.75e-08 6.35e-08 4.26e-07 1.57e-07 4.65e-07 erg/cm2
Peak flux Cutoff-PL 7.87e-01 6.98e-01 3.20e-01 8.94e-02 1.87e+00 1.89e+00 ph/cm2/s
Error 1.92e-01 1.23e-01 8.17e-02 1.27e-01 2.71e-01 2.94e-01 ph/cm2/s
Fluence Band 4.29e-07 6.83e-07 6.38e-07 9.70e-07 2.10e-06 2.74e-06 erg/cm2
Error 5.35e-08 5.27e-08 7.42e-08 4.38e-07 1.56e-07 3.92e-07 erg/cm2
Peak flux Band 7.89e-01 6.96e-01 3.19e-01 1.06e-01 1.87e+00 1.92e+00 ph/cm2/s
Error 1.87e-01 1.17e-01 8.37e-02 1.21e-01 2.70e-01 3.08e-01 ph/cm2/s
=== Time-averaged spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.970 0.109 - - 4.93e-03 3.19e-04 62.254 57
CPL 1.526 0.456 48.7 38.7 8.55e-03 5.18e-03 59.130 0
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 2.018 0.251 - - 1.26e-02 2.18e-03 60.332 57
CPL 1.230 1.127 42.6 5000.0 3.51e-02 9.11e-02 58.573 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: 0.064000 sec.
T50 in the 50-300 keV band: 0.064000 sec.
=== Table of the duration information ==
Value tstart tstop
T100 47.660 -41.796 5.864
T90 43.512 -39.940 3.572
T50 14.468 -32.480 -18.012
Peak 1.000 -24.864 -23.864
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
40.7097 +30.3663 0.0247 35.3 152.2 0.3668 7.8 TRIG_00228316
------------------------------------------
Foreground time interval of the image:
-6.699 5.864 (delta_t = 12.563 [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 -41.796 sec. to 5.864 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.96994 ( -0.108267 0.110482 )
Norm@50keV : 4.931823E-03 ( -3.207475E-04 3.169803E-04) )
------------------------------------------------------------
Chi-Squared = 62.25437 using 59 PHA bins.
Reduced chi-squared = 1.092182 for 57 degrees of freedom
Null hypothesis probability = 0.295
Photon flux (15-150 keV) in 47.66 sec: 0.729734 ( -0.043583 0.043694 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.16462e-06 ( -1.35412e-07 1.36217e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -41.796 sec. to 5.864 sec.
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.52640 ( -0.482679 0.429490 )
Epeak [keV] : 48.6788 ( -13.2978 64.1065 )
Norm@50keV : 8.552251E-03 ( -3.457373E-03 6.904133E-03) )
------------------------------------------------------------
Chi-Squared = 59.12956 using 59 PHA bins.
but latest trial 23.9367 gives Chi-Squared = 3.30610
Reduced chi-squared = 1.055885 for 56 degrees of freedom
Null hypothesis probability = 0.362
Photon flux (15-150 keV) in 47.66 sec: 0.712580 ( -0.046539 0.046457 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.08477e-06 ( -1.56797e-07 1.56625e-07 ) ergs/cm2
Band function
Time interval is from -41.796 sec. to 5.864 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.52563 ( -0.430307 0.478122 )
beta : -8.57840 ( -1.42160 6.64902 )
Epeak [keV] : 48.6462 ( -18.3735 64.1274 )
Norm@50keV : 8.559971E-03 ( -3.470650E-03 6.896227E-03) )
------------------------------------------------------------
Chi-Squared = 59.12952 using 59 PHA bins.
Reduced chi-squared = 1.075082 for 55 degrees of freedom
Null hypothesis probability = 0.327
Photon flux (15-150 keV) in 47.66 sec: 0.712563 ( -0.04654 0.046585 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.09505e-06 ( -1.52388e-07 1.59556e-07 ) ergs/cm2
Peak spectrum fit using the pre-slew DRM
Power-law model
Time interval is from -24.864 sec. to -23.864 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.01783 ( -0.240840 0.261344 )
Norm@50keV : 1.257896E-02 ( -2.211977E-03 2.142359E-03) )
------------------------------------------------------------
Chi-Squared = 60.33154 using 59 PHA bins.
Reduced chi-squared = 1.058448 for 57 degrees of freedom
Null hypothesis probability = 0.356
Photon flux (15-150 keV) in 1.000 sec: 1.90249 ( -0.26702 0.2671 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.16116e-07 ( -1.89024e-08 1.9232e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -24.864 sec. to -23.864 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.23031 ( -1.25918 0.995777 )
Epeak [keV] : 42.6109 ( -42.6009 9957.39 )
Norm@50keV : 3.514904E-02 ( -3.514905E-02 0.147131 )
------------------------------------------------------------
Chi-Squared = 58.57280 using 59 PHA bins.
Reduced chi-squared = 1.045943 for 56 degrees of freedom
Null hypothesis probability = 0.381
Photon flux (15-150 keV) in 1.000 sec: 1.86993 ( -0.27113 0.27037 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.10617e-07 ( -1.97334e-08 2.0495e-08 ) ergs/cm2
Band function
Time interval is from -24.864 sec. to -23.864 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.23481 ( -8.76519 1.29591 )
beta : -9.02453 ( -0.975470 7.15085 )
Epeak [keV] : 42.6392 ( -17.3120 9957.36 )
Norm@50keV : 3.491952E-02 ( -3.491952E-02 0.147467 )
------------------------------------------------------------
Chi-Squared = 58.57290 using 59 PHA bins.
Reduced chi-squared = 1.064962 for 55 degrees of freedom
Null hypothesis probability = 0.346
Photon flux (15-150 keV) in 1.000 sec: 1.87159 ( -0.27231 0.26778 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.10825e-07 ( -1.99945e-08 2.0005e-08 ) ergs/cm2
Plot creation:
Wed Jan 2 03:45:49 EST 2008