batgrbproduct Analysis for Trigger=321574
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): Sat Aug 23 23:19:26 EDT 2008
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger321574/GCN5_download_cron
======================================================================
Trigger: 00321574 Segment: 000
BAT Trigger Time: 241201885.368 [s; MET]
Trigger Stop: 241201885.384 [s; MET]
UTC: 2008-08-23T16:31:22.326540 [includes UTCF correction]
Where From?: (*SHORT BURST*) TDRSS scaled map message
BAT
RA: 75.2422167412428 Dec: 45.2417415081925 [deg; J2000]
Catalogged Source?: YES
Point Source?: YES
GRB Indicated?: NO [ by BAT flight software ]
Image S/N Ratio: 6.81
Image Trigger?: NO
Rate S/N Ratio: 15.5884572681199 [ if not an image trigger ]
Image S/N Ratio: 6.81
Flight Position: [ source = BAT ]
RA: 75.2422167412428 Dec: 45.2417415081925 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 75.1973145933967 Dec: 45.2339568865823 [deg; J2000]
{ 05h 00m 47.4s , +45d 14' 02.2" }
+/- 2.96458879187619 [arcmin] (estimated 90% radius based on SNR)
+/- 1.52666174563965 [arcmin] (formal 1-sigma fit error)
SNR: 6.43996391322113
Angular difference between Flight and Ground position is 1.953764 arcmin
Partial Coding Fraction: 1.015625 [ including projection effects ]
Duration
T90: 0.0200000107288361 +/- 0.00565686571343518
Measured from: 8.94069671630859e-08
to: 0.0200001001358032 [s; relative to TRIGTIME]
T50: 0.0119999945163727 +/- 0.00400000810623169
Measured from: 8.94069671630859e-08
to: 0.0120000839233398 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: -0.488000005483627
to: 0.511999994516373 [s; relative to TRIGTIME]
Total Fluence
Measured from: 0
to: 0.0200000107288361 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.005194 0.006795 0.002850 -0.000049
0.001139 0.001128 0.000995 0.000758 [error]
Peak 0.005388 0.007037 0.003237 -0.000019
0.001182 0.001174 0.001039 0.000777 [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 1.46e-09 1.64e-09 1.31e-09 1.73e-09 5.05e-09 6.88e-09 erg/cm2
Error 4.43e-10 4.18e-10 5.91e-10 1.50e-09 1.44e-09 0.00e+00 erg/cm2
Peak flux Power-law 2.07e+00 1.28e+00 5.06e-01 2.70e-01 3.99e+00 4.13e+00 ph/cm2/s
Error 6.31e-01 3.19e-01 2.20e-01 2.16e-01 9.62e-01 9.96e-01 ph/cm2/s
Fluence Cutoff-PL 1.36e-09 2.01e-09 8.62e-10 6.92e-11 4.30e-09 4.69e-09 erg/cm2
Error 5.03e-10 6.13e-10 6.41e-10 1.25e-09 1.13e-09 2.36e-09 erg/cm2
Peak flux Cutoff-PL 1.90e+00 1.60e+00 3.24e-01 9.14e-03 3.83e+00 3.83e+00 ph/cm2/s
Error 7.11e-01 4.75e-01 3.03e-01 8.44e-02 9.83e-01 9.87e-01 ph/cm2/s
Fluence Band 1.35e-09 1.99e-09 9.44e-10 5.25e-10 4.57e-09 5.48e-09 erg/cm2
Error 4.94e-10 6.04e-10 7.44e-10 8.33e-10 1.40e-09 0.00e+00 erg/cm2
Peak flux Band 1.98e+00 1.49e+00 4.21e-01 1.48e-01 3.98e+00 4.07e+00 ph/cm2/s
Error 4.32e-01 3.68e-01 1.37e-01 8.74e-02 9.40e-01 9.68e-01 ph/cm2/s
=== Time-averaged spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 2.333 0.461 - - 2.62e-02 8.93e-03 53.935 57
CPL 0.389 0.000 29.3 20.5 4.44e-01 2.41e+01 51.907 0
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 2.336 0.450 - - 2.24e-02 7.56e-03 52.297 57
CPL 0.339 2.511 28.8 20.9 4.36e-01 0.00e+00 49.852 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 0.020 0.000 0.020
T90 0.020 0.000 0.020
T50 0.012 0.000 0.012
Peak 1.000 -0.488 0.512
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
75.1973 +45.2340 0.0299 0.1 66.5 0.0132 6.4 TRIG_00321574
------------------------------------------
Foreground time interval of the image:
0.000 0.020 (delta_t = 0.020 [sec])
Background time interval of the image:
-119.368 0.000 (delta_t = 119.368 [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 0.000 sec. to 0.020 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.33297 ( -0.426593 0.494672 )
Norm@50keV : 2.616925E-02 ( -9.028174E-03 8.836146E-03) )
------------------------------------------------------------
Chi-Squared = 53.93549 using 59 PHA bins.
Reduced chi-squared = 0.9462366 for 57 degrees of freedom
Null hypothesis probability = 0.591
Photon flux (15-150 keV) in 2.0000E-02 sec: 4.65870 ( -1.11934 1.11949 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.04798e-09 ( -1.41604e-09 1.4571e-09 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.000 sec. to 0.020 sec.
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.388742 ( )
Epeak [keV] : 29.2745 ( -26.8595 14.0699 )
Norm@50keV : 0.443551 ( -0.456403 47.6804 )
------------------------------------------------------------
Chi-Squared = 51.90710 using 59 PHA bins.
but latest trial 2.27574 gives Chi-Squared = 43.0689
Reduced chi-squared = 0.9269125 for 56 degrees of freedom
Null hypothesis probability = 0.630
Photon flux (15-150 keV) in 2.0000E-02 sec: 4.45993 ( -1.12544 1.1424 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.29944e-09 ( -6.4324e-10 1.6219e-09 ) ergs/cm2
Band function
Time interval is from 0.000 sec. to 0.020 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.39614 ( -11.2666 3.73337 )
beta : -4.36986 ( -7.03313 12.9429 )
Epeak [keV] : 23.5553 ( -24.5838 24.4226 )
Norm@50keV : 0.102512 ( -9.68489 1579.98 )
------------------------------------------------------------
Chi-Squared = 52.35594 using 59 PHA bins.
Reduced chi-squared = 0.9519262 for 55 degrees of freedom
Null hypothesis probability = 0.576
Photon flux (15-150 keV) in 2.0000E-02 sec: 4.65640 ( ) ph/cm2/s
Energy fluence (15-150 keV) : 4.5659e-09 ( -1.44454e-09 1.34886e-09 ) ergs/cm2
Peak spectrum fit using the pre-slew DRM
Power-law model
Time interval is from 0.000 sec. to 0.024 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.33566 ( -0.419228 0.481750 )
Norm@50keV : 2.240521E-02 ( -7.630138E-03 7.499741E-03) )
------------------------------------------------------------
Chi-Squared = 52.29702 using 59 PHA bins.
Reduced chi-squared = 0.9174916 for 57 degrees of freedom
Null hypothesis probability = 0.652
Photon flux (15-150 keV) in 2.4000E-02 sec: 3.99468 ( -0.96223 0.96241 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.17154e-09 ( -1.43045e-09 1.50391e-09 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.000 sec. to 0.024 sec.
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.338974 ( -3.33897 1.68328 )
Epeak [keV] : 28.7848 ( -28.7748 13.0343 )
Norm@50keV : 0.435872 ( )
------------------------------------------------------------
Chi-Squared = 49.85173 using 59 PHA bins.
but latest trial 2.03848 gives Chi-Squared = 3.78740
Reduced chi-squared = 0.8902096 for 56 degrees of freedom
Null hypothesis probability = 0.705
Photon flux (15-150 keV) in 2.4000E-02 sec: 3.83142 ( -0.98855 0.97799 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.37659e-09 ( -1.29775e-09 1.62461e-09 ) ergs/cm2
Band function
Time interval is from 0.000 sec. to 0.024 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.24356 ( -11.9263 3.07371 )
beta : -9.31906 ( -6.66272 1.02160 )
Epeak [keV] : 24.9799 ( -10.8070 39.4462 )
Norm@50keV : 0.112674 ( -21.8894 1188.97 )
------------------------------------------------------------
Chi-Squared = 50.32266 using 59 PHA bins.
Reduced chi-squared = 0.9149575 for 55 degrees of freedom
Null hypothesis probability = 0.654
Photon flux (15-150 keV) in 2.4000E-02 sec: 3.98128 ( -0.9374 0.94192 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.66802e-09 ( -1.3697e-09 1.21591e-09 ) ergs/cm2
Plot creation:
Sat Aug 23 23:26:16 EDT 2008