batgrbproduct Analysis for Trigger=315615
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): Tue Jul 1 20:56:31 EDT 2008
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger315615/GCN5_download_cron
======================================================================
Trigger: 00315615 Segment: 000
BAT Trigger Time: 236600020.544 [s; MET]
Trigger Stop: 236600021.568 [s; MET]
UTC: 2008-07-01T10:13:37.636600 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 45.8375449298875 Dec: 75.4918923999807 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 16.1
Image Trigger?: NO
Rate S/N Ratio: 26.153393661244 [ if not an image trigger ]
Image S/N Ratio: 16.1
Flight Position: [ source = BAT ]
RA: 45.8375449298875 Dec: 75.4918923999807 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 45.9404560988669 Dec: 75.4776178954597 [deg; J2000]
{ 03h 03m 45.7s , +75d 28' 39.4" }
+/- 1.37605332254784 [arcmin] (estimated 90% radius based on SNR)
+/- 0.446612994829778 [arcmin] (formal 1-sigma fit error)
SNR: 19.2782675768269
Angular difference between Flight and Ground position is 1.768790 arcmin
Partial Coding Fraction: 0.5546875 [ including projection effects ]
Duration
T90: 17.66400000453 +/- 9.11522680546778
Measured from: -2.10400000214577
to: 15.5600000023842 [s; relative to TRIGTIME]
T50: 4.48000001907349 +/- 1.19561867603917
Measured from: -0.631999999284744
to: 3.84800001978874 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: -0.0760000050067902
to: 0.92399999499321 [s; relative to TRIGTIME]
Total Fluence
Measured from: -2.74399998784065
to: 24.5839999914169 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.570225 0.552702 0.228216 0.036348
0.036892 0.036855 0.033805 0.032139 [error]
Peak 0.100355 0.099370 0.035642 0.009148
0.008340 0.008211 0.007054 0.006199 [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 1.93e-07 2.26e-07 1.91e-07 2.73e-07 7.08e-07 8.87e-07 erg/cm2
Error 2.13e-08 1.87e-08 3.08e-08 8.57e-08 6.90e-08 1.22e-07 erg/cm2
Peak flux Power-law 1.15e+00 7.20e-01 2.91e-01 1.59e-01 2.24e+00 2.32e+00 ph/cm2/s
Error 1.47e-01 7.39e-02 5.53e-02 5.49e-02 2.20e-01 2.29e-01 ph/cm2/s
Fluence Cutoff-PL 1.85e-07 2.40e-07 1.80e-07 9.78e-08 6.64e-07 7.04e-07 erg/cm2
Error 2.37e-08 2.45e-08 3.66e-08 1.35e-07 8.06e-08 1.69e-07 erg/cm2
Peak flux Cutoff-PL 1.04e+00 8.42e-01 2.46e-01 2.15e-02 2.15e+00 2.15e+00 ph/cm2/s
Error 1.65e-01 1.03e-01 7.24e-02 3.14e-02 2.22e-01 1.69e-01 ph/cm2/s
Fluence Band 1.83e-07 2.39e-07 1.79e-07 9.79e-08 6.63e-07 7.02e-07 erg/cm2
Error 2.34e-08 2.44e-08 3.65e-08 1.28e-07 8.05e-08 1.69e-07 erg/cm2
Peak flux Band 1.04e+00 8.43e-01 2.45e-01 2.68e-02 2.15e+00 2.14e+00 ph/cm2/s
Error 1.61e-01 5.14e-02 3.43e-02 4.75e-02 2.16e-01 2.10e-01 ph/cm2/s
=== Time-averaged spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 2.243 0.170 - - 2.74e-03 3.16e-04 43.328 57
CPL 1.670 0.549 22.6 17.6 6.01e-03 6.90e-03 41.052 0
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 2.305 0.194 - - 1.28e-02 1.84e-03 68.848 57
CPL 0.758 1.022 29.6 9.2 1.16e-01 2.96e-01 59.823 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: 3.584000 sec.
T50 in the 50-300 keV band: 2.048000 sec.
=== Table of the duration information ==
Value tstart tstop
T100 27.328 -2.744 24.584
T90 17.664 -2.104 15.560
T50 4.480 -0.632 3.848
Peak 1.000 -0.076 0.924
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
45.9405 +75.4776 0.0100 27.1 -68.0 1.4144 19.3 TRIG_00315615
------------------------------------------
Foreground time interval of the image:
-2.744 24.584 (delta_t = 27.328 [sec])
Background time interval of the image:
-239.544 -2.744 (delta_t = 236.800 [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 -2.744 sec. to 24.584 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.24292 ( -0.164938 0.174090 )
Norm@50keV : 2.736915E-03 ( -3.181105E-04 3.132732E-04) )
------------------------------------------------------------
Chi-Squared = 43.32780 using 59 PHA bins.
Reduced chi-squared = 0.7601368 for 57 degrees of freedom
Null hypothesis probability = 0.909
Photon flux (15-150 keV) in 27.33 sec: 0.463580 ( -0.036751 0.036762 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.07811e-07 ( -6.81528e-08 6.97981e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -2.744 sec. to 24.584 sec.
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.66954 ( -0.764305 0.333135 )
Epeak [keV] : 22.5963 ( -21.7857 13.4572 )
Norm@50keV : 6.007569E-03 ( -2.640091E-03 1.115381E-02) )
------------------------------------------------------------
Chi-Squared = 41.05194 using 59 PHA bins.
but latest trial 2.00267 gives Chi-Squared = 8.10708
Reduced chi-squared = 0.7330704 for 56 degrees of freedom
Null hypothesis probability = 0.933
Photon flux (15-150 keV) in 27.33 sec: 0.451247 ( -0.038981 0.019568 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.64428e-07 ( -7.77429e-08 8.3403e-08 ) ergs/cm2
Band function
Time interval is from -2.744 sec. to 24.584 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.67374 ( -8.32626 0.379812 )
beta : -8.98947 ( -1.01053 6.81582 )
Epeak [keV] : 22.5188 ( -22.4188 13.5239 )
Norm@50keV : 5.964989E-03 ( -2.430074E-03 1.119126E-02) )
------------------------------------------------------------
Chi-Squared = 41.05239 using 59 PHA bins.
Reduced chi-squared = 0.7464070 for 55 degrees of freedom
Null hypothesis probability = 0.919
Photon flux (15-150 keV) in 27.33 sec: 0.451275 ( -0.039009 0.039033 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.63455e-07 ( -7.77866e-08 8.32198e-08 ) ergs/cm2
Peak spectrum fit using the pre-slew DRM
Power-law model
Time interval is from -0.056 sec. to 0.904 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.30531 ( -0.187495 0.200458 )
Norm@50keV : 1.276739E-02 ( -1.854684E-03 1.833016E-03) )
------------------------------------------------------------
Chi-Squared = 68.84841 using 59 PHA bins.
Reduced chi-squared = 1.207867 for 57 degrees of freedom
Null hypothesis probability = 0.135
Photon flux (15-150 keV) in 0.9600 sec: 2.23782 ( -0.22033 0.22034 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.17167e-07 ( -1.38893e-08 1.43952e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.056 sec. to 0.904 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.758487 ( -1.11733 0.926059 )
Epeak [keV] : 29.6462 ( -12.2052 6.16990 )
Norm@50keV : 0.116032 ( -0.116032 0.476403 )
------------------------------------------------------------
Chi-Squared = 59.82298 using 59 PHA bins.
Reduced chi-squared = 1.068267 for 56 degrees of freedom
Null hypothesis probability = 0.339
Photon flux (15-150 keV) in 0.9600 sec: 2.14922 ( -0.22142 0.2226 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.03588e-07 ( -1.32232e-08 1.46362e-08 ) ergs/cm2
Band function
Time interval is from -0.056 sec. to 0.904 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.959655 ( -0.740510 1.01138 )
beta : -9.36466 ( -0.635340 6.71904 )
Epeak [keV] : 28.7869 ( -14.9407 7.28179 )
Norm@50keV : 8.699273E-02 ( -1.765837E-02 0.222761 )
------------------------------------------------------------
Chi-Squared = 59.94207 using 59 PHA bins.
Reduced chi-squared = 1.089856 for 55 degrees of freedom
Null hypothesis probability = 0.301
Photon flux (15-150 keV) in 0.9600 sec: 2.15182 ( -0.22115 0.21067 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.0478e-07 ( -1.31511e-08 1.30435e-08 ) ergs/cm2
Plot creation:
Tue Jul 1 21:30:52 EDT 2008