batgrbproduct Analysis for Trigger=321174
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 Aug 22 19:25:34 EDT 2008
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger321174/GCN5_download_cron
======================================================================
Trigger: 00321174 Segment: 000
BAT Trigger Time: 241101722.496 [s; MET]
Trigger Stop: 241101722.56 [s; MET]
UTC: 2008-08-22T12:41:59.457500 [includes UTCF correction]
Where From?: (*SHORT BURST*) TDRSS scaled map message
BAT
RA: 75.2705886198806 Dec: 45.2723231104941 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 17.33
Image Trigger?: NO
Rate S/N Ratio: 72.6636084983398 [ if not an image trigger ]
Image S/N Ratio: 17.33
Flight Position: [ source = BAT ]
RA: 75.2705886198806 Dec: 45.2723231104941 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 75.2658650404187 Dec: 45.2715038976962 [deg; J2000]
{ 05h 01m 03.8s , +45d 16' 17.4" }
+/- 1.24067258807296 [arcmin] (estimated 90% radius based on SNR)
+/- 0.517042149098597 [arcmin] (formal 1-sigma fit error)
SNR: 22.3523093209146
Angular difference between Flight and Ground position is 0.205419 arcmin
Partial Coding Fraction: 0.6796875 [ including projection effects ]
Duration
T90: 0.0760000050067902 +/- 0.0144222095322683
Measured from: -0.00799989700317383
to: 0.0680001080036163 [s; relative to TRIGTIME]
T50: 0.0280000269412994 +/- 0.00565684464005017
Measured from: 0.0160000920295715
to: 0.044000118970871 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: -0.467999994754791
to: 0.532000005245209 [s; relative to TRIGTIME]
Total Fluence
Measured from: -0.0199999809265137
to: 0.0800000131130219 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.049562 0.078156 0.019972 0.001360
0.003798 0.004472 0.002684 0.001639 [error]
Peak 0.050060 0.078695 0.019513 0.001524
0.003824 0.004502 0.002720 0.001654 [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 2.02e-08 2.18e-08 1.67e-08 2.09e-08 6.65e-08 8.21e-08 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 Power-law 6.47e+00 3.87e+00 1.48e+00 7.54e-01 1.22e+01 1.26e+01 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 Cutoff-PL 1.55e-08 3.60e-08 1.23e-08 2.15e-10 6.41e-08 6.44e-08 erg/cm2
Error 2.28e-09 3.37e-09 2.93e-09 2.91e-10 5.25e-09 0.00e+00 erg/cm2
Peak flux Cutoff-PL 4.70e+00 6.25e+00 1.21e+00 1.19e-02 1.22e+01 1.22e+01 ph/cm2/s
Error 7.34e-01 5.86e-01 2.70e-01 1.91e-02 1.01e+00 1.01e+00 ph/cm2/s
Fluence Band 1.53e-08 3.62e-08 1.29e-08 3.09e-09 6.63e-08 7.18e-08 erg/cm2
Error 2.60e-09 3.24e-09 1.84e-09 4.13e-10 5.15e-09 5.83e-09 erg/cm2
Peak flux Band 4.93e+00 6.26e+00 1.28e+00 1.23e-01 1.23e+01 1.26e+01 ph/cm2/s
Error 8.47e-01 5.62e-01 2.32e-01 1.12e-01 9.59e-01 1.08e+00 ph/cm2/s
=== Time-averaged spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 2.388 0.000 - - 6.84e-02 0.00e+00 128.662 57
CPL -2.257 0.986 35.3 1.9 4.36e+01 2.91e+01 61.423 0
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 2.388 0.000 - - 6.65e-02 0.00e+00 128.771 57
CPL -2.212 1.017 35.2 1.9 3.99e+01 3.22e+01 64.519 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 0.100 -0.020 0.080
T90 0.076 -0.008 0.068
T50 0.028 0.016 0.044
Peak 1.000 -0.468 0.532
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
75.2659 +45.2715 0.0086 32.2 -38.0 0.1488 22.4 TRIG_00321174
------------------------------------------
Foreground time interval of the image:
-0.020 0.080 (delta_t = 0.100 [sec])
Background time interval of the image:
-104.395 -0.020 (delta_t = 104.375 [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 -0.020 sec. to 0.080 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.38776 ( )
Norm@50keV : 6.838708E-02 ( )
------------------------------------------------------------
Chi-Squared = 128.6625 using 59 PHA bins.
Reduced chi-squared = 2.257236 for 57 degrees of freedom
Null hypothesis probability = 1.856E-07
Photon flux (15-150 keV) in 1.0000E-01 sec: 12.5635 ( ) ph/cm2/s
Energy fluence (15-150 keV) : 6.65307e-08 ( 0 0 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.020 sec. to 0.080 sec.
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -2.25691 ( -0.743089 1.22871 )
Epeak [keV] : 35.3365 ( -1.95571 1.92863 )
Norm@50keV : 43.6076 ( -35.7388 22.3677 )
------------------------------------------------------------
Chi-Squared = 61.42297 using 59 PHA bins.
but latest trial 33.3808 gives Chi-Squared = 2.75396
Reduced chi-squared = 1.096839 for 56 degrees of freedom
Null hypothesis probability = 0.288
Photon flux (15-150 keV) in 1.0000E-01 sec: 12.6063 ( -1.0293 1.0534 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.40581e-08 ( -5.1684e-09 5.3395e-09 ) ergs/cm2
Band function
Time interval is from -0.020 sec. to 0.080 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : 0.546342 ( -2.87254 1.21089 )
beta : -9.30677 ( -2.16226 0.659245 )
Epeak [keV] : 34.6074 ( -1.27526 3.81474 )
Norm@50keV : 3.99542 ( -62.9080 984.847 )
------------------------------------------------------------
Chi-Squared = 67.05444 using 59 PHA bins.
Reduced chi-squared = 1.219172 for 55 degrees of freedom
Null hypothesis probability = 0.128
Photon flux (15-150 keV) in 1.0000E-01 sec: 12.7150 ( -1.0183 0.9912 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.62829e-08 ( -5.1679e-09 5.1274e-09 ) ergs/cm2
Peak spectrum fit using the pre-slew DRM
Power-law model
Time interval is from -0.020 sec. to 0.084 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.38779 ( )
Norm@50keV : 6.647793E-02 ( )
------------------------------------------------------------
Chi-Squared = 128.7709 using 59 PHA bins.
Reduced chi-squared = 2.259139 for 57 degrees of freedom
Null hypothesis probability = 1.798E-07
Photon flux (15-150 keV) in 0.1040 sec: 12.2130 ( ) ph/cm2/s
Energy fluence (15-150 keV) : 6.72543e-08 ( 0 0 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.020 sec. to 0.084 sec.
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -2.21188 ( -0.788123 1.24628 )
Epeak [keV] : 35.2488 ( -1.91373 1.95169 )
Norm@50keV : 39.8811 ( -39.8811 24.4436 )
------------------------------------------------------------
Chi-Squared = 64.51945 using 59 PHA bins.
but latest trial 33.3475 gives Chi-Squared = 2.56257
Reduced chi-squared = 1.152133 for 56 degrees of freedom
Null hypothesis probability = 0.203
Photon flux (15-150 keV) in 0.1040 sec: 12.1810 ( -0.9969 1.0241 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.42658e-08 ( -5.27582e-09 5.40748e-09 ) ergs/cm2
Band function
Time interval is from -0.020 sec. to 0.084 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : 0.493875 ( -2.89630 1.22654 )
beta : -9.07964 ( -1.94876 0.632986 )
Epeak [keV] : 34.5297 ( -1.76226 2.82059 )
Norm@50keV : 3.60007 ( -69.2657 994.397 )
------------------------------------------------------------
Chi-Squared = 70.01061 using 59 PHA bins.
Reduced chi-squared = 1.272920 for 55 degrees of freedom
Null hypothesis probability = 8.368E-02
Photon flux (15-150 keV) in 0.1040 sec: 12.3068 ( -0.9809 0.9362 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.64288e-08 ( -5.25086e-09 5.3821e-09 ) ergs/cm2
Plot creation:
Fri Aug 22 19:37:52 EDT 2008