batgrbproduct Analysis for Trigger=303631
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 Feb 19 14:01:39 EST 2008
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger303631/GCN5_download_cron
======================================================================
Trigger: 00303631 Segment: 000
BAT Trigger Time: 225071869.76 [s; MET]
Trigger Stop: 225071873.856 [s; MET]
UTC: 2008-02-18T23:57:47.175420 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 177.951347600546 Dec: -53.1004105987458 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 7.25
Image Trigger?: NO
Rate S/N Ratio: 11.7898261225516 [ if not an image trigger ]
Image S/N Ratio: 7.25
Flight Position: [ source = BAT ]
RA: 177.951347600546 Dec: -53.1004105987458 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 177.924581463585 Dec: -53.0861669581549 [deg; J2000]
{ 11h 51m 41.9s , -53d 05' 10.2" }
+/- 1.97130318473328 [arcmin] (estimated 90% radius based on SNR)
+/- 1.59982063592579 [arcmin] (formal 1-sigma fit error)
SNR: 11.5356497313859
RA = 11h 51m 41.9s (177.924581 deg.)
Dec = -53d 5' 10" (-53.086167 deg.)
Angular difference between Flight and Ground position is 1.288585 arcmin
Partial Coding Fraction: 0.1015625 [ including projection effects ]
Duration
T90: 5.23199996352196 +/- 0.92329843911248
Measured from: -0.607999980449677
to: 4.62399998307228 [s; relative to TRIGTIME]
T50: 2.0799999833107 +/- 0.815725444435808
Measured from: 0.256000012159348
to: 2.33599999547005 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 0.291999995708466
to: 1.29199999570847 [s; relative to TRIGTIME]
Total Fluence
Measured from: -0.863999992609024
to: 5.08799999952316 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.460411 0.470322 0.097840 -0.000046
0.051400 0.052927 0.042549 0.036622 [error]
Peak 0.123595 0.117653 0.041702 0.008422
0.021981 0.023336 0.018694 0.015990 [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 2.06e-07 1.89e-07 1.18e-07 1.15e-07 5.63e-07 6.38e-07 erg/cm2
Error 3.29e-08 2.91e-08 3.51e-08 6.17e-08 8.94e-08 1.22e-07 erg/cm2
Peak flux Power-law 1.69e+00 9.73e-01 3.55e-01 1.71e-01 3.11e+00 3.19e+00 ph/cm2/s
Error 4.36e-01 2.11e-01 1.41e-01 1.23e-01 6.36e-01 6.53e-01 ph/cm2/s
Fluence Cutoff-PL 1.97e-07 2.32e-07 4.99e-08 8.69e-10 4.80e-07 4.80e-07 erg/cm2
Error 3.64e-08 4.11e-08 5.04e-08 1.18e-08 8.79e-08 8.86e-08 erg/cm2
Peak flux Cutoff-PL 1.59e+00 1.11e+00 3.27e-01 4.05e-02 3.06e+00 3.07e+00 ph/cm2/s
Error 4.83e-01 3.03e-01 2.50e-01 1.36e-01 6.40e-01 6.48e-01 ph/cm2/s
Fluence Band 1.99e-07 2.19e-07 8.73e-08 2.14e-08 5.18e-07 5.43e-07 erg/cm2
Error 3.89e-08 4.85e-08 3.29e-08 4.99e-08 8.37e-08 1.26e-07 erg/cm2
Peak flux Band 1.59e+00 1.10e+00 3.30e-01 6.19e-02 3.07e+00 3.09e+00 ph/cm2/s
Error 4.50e-01 2.77e-01 1.61e-01 1.37e-01 6.33e-01 6.46e-01 ph/cm2/s
=== Time-averaged spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 2.667 0.276 - - 8.99e-03 1.99e-03 71.028 57
CPL 0.146 2.383 23.6 14.5 4.41e-01 0.00e+00 62.922 56
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 2.453 0.406 - - 1.63e-02 4.99e-03 45.240 57
CPL 1.337 1.573 22.4 18.9 7.98e-02 1.57e+00 44.008 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 5.952 -0.864 5.088
T90 5.232 -0.608 4.624
T50 2.080 0.256 2.336
Peak 1.000 0.292 1.292
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
177.9246 -53.0862 0.0167 45.7 140.5 1.0635 11.5 TRIG_00303631
------------------------------------------
Foreground time interval of the image:
-0.864 5.088 (delta_t = 5.952 [sec])
Background time interval of the image:
-239.760 -0.864 (delta_t = 238.896 [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 -0.864 sec. to 5.088 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.66675 ( -0.260725 0.290973 )
Norm@50keV : 8.985390E-03 ( -1.987197E-03 1.994424E-03) )
------------------------------------------------------------
Chi-Squared = 71.02791 using 59 PHA bins.
Reduced chi-squared = 1.246104 for 57 degrees of freedom
Null hypothesis probability = 0.100
Photon flux (15-150 keV) in 5.952 sec: 1.96197 ( -0.26273 0.26276 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.62593e-07 ( -8.81336e-08 9.05799e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.864 sec. to 5.088 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.145726 ( -3.14573 1.61979 )
Epeak [keV] : 23.5870 ( -23.5770 5.49663 )
Norm@50keV : 0.440858 ( )
------------------------------------------------------------
Chi-Squared = 62.92170 using 59 PHA bins.
Reduced chi-squared = 1.123602 for 56 degrees of freedom
Null hypothesis probability = 0.245
Photon flux (15-150 keV) in 5.952 sec: 1.88681 ( -0.2681 0.26682 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.80483e-07 ( -8.1568e-08 9.41547e-08 ) ergs/cm2
Band function
Time interval is from -0.864 sec. to 5.088 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.34756 ( -3.07875 0.720561 )
beta : -9.36174 ( -0.638265 19.3617 )
Epeak [keV] : 17.0582 ( -3.68729 6.73373 )
Norm@50keV : 6.466440E-02 ( -195.477 1103.97 )
------------------------------------------------------------
Chi-Squared = 64.45119 using 59 PHA bins.
Reduced chi-squared = 1.171840 for 55 degrees of freedom
Null hypothesis probability = 0.180
Photon flux (15-150 keV) in 5.952 sec: 1.92409 ( -0.25319 0.26246 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.17585e-07 ( -7.4778e-08 9.26262e-08 ) ergs/cm2
Peak spectrum fit using the pre-slew DRM
Power-law model
Time interval is from 0.288 sec. to 1.296 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.45328 ( -0.371490 0.440707 )
Norm@50keV : 1.626242E-02 ( -5.076902E-03 4.894663E-03) )
------------------------------------------------------------
Chi-Squared = 45.24049 using 59 PHA bins.
Reduced chi-squared = 0.7936929 for 57 degrees of freedom
Null hypothesis probability = 0.870
Photon flux (15-150 keV) in 1.008 sec: 3.10546 ( -0.63618 0.63625 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.61994e-07 ( -3.8678e-08 3.9811e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.288 sec. to 1.296 sec.
Parameters : value lower 90% higher 90%
Photon index: 1.33664 ( -2.46570 0.679951 )
Epeak [keV] : 22.4453 ( -21.1242 16.6274 )
Norm@50keV : 7.982522E-02 ( -7.982522E-02 3.06353 )
------------------------------------------------------------
Chi-Squared = 44.00804 using 59 PHA bins.
but latest trial 2.03196 gives Chi-Squared = 4.75490
but latest trial 1.32110 gives Chi-Squared = 4.22211
Reduced chi-squared = 0.7858578 for 56 degrees of freedom
Null hypothesis probability = 0.877
Photon flux (15-150 keV) in 1.008 sec: 3.06092 ( -0.6398 0.63989 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.51862e-07 ( -3.77315e-08 4.22937e-08 ) ergs/cm2
Band function
Time interval is from 0.288 sec. to 1.296 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.49359 ( -8.50641 4.81456 )
beta : -4.54489 ( -5.45511 14.4741 )
Epeak [keV] : 20.3505 ( -20.2505 42.6629 )
Norm@50keV : 6.301516E-02 ( -6.301516E-02 0.125519 )
------------------------------------------------------------
Chi-Squared = 44.02885 using 59 PHA bins.
Reduced chi-squared = 0.8005245 for 55 degrees of freedom
Null hypothesis probability = 0.855
Photon flux (15-150 keV) in 1.008 sec: 3.07002 ( -0.64064 0.62561 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.62614e-07 ( -3.39192e-08 3.32811e-08 ) ergs/cm2
Plot creation:
Tue Feb 19 14:35:04 EST 2008