batgrbproduct Analysis for Trigger=308224
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 Apr 2 21:09:00 EDT 2008
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger308224/SDC
======================================================================
Trigger: 00308224 Segment: 000
BAT Trigger Time: 228689448 [s; MET]
Trigger Stop: 228689560 [s; MET]
UTC: 2008-03-31T20:50:45.316000 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 268.621376273249 Dec: -26.3206436351591 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 9.1
Image Trigger?: YES
Rate S/N Ratio: 0 [ if not an image trigger ]
Image S/N Ratio: 9.1
Flight Position: [ source = BAT ]
RA: 268.621376273249 Dec: -26.3206436351591 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 268.562819730521 Dec: -26.3656104745381 [deg; J2000]
{ 17h 54m 15.1s , -26d 21' 56.2" }
+/- 2.38514780504289 [arcmin] (estimated 90% radius based on SNR)
+/- 1.2699634478527 [arcmin] (formal 1-sigma fit error)
SNR: 8.78639680932166
RA = 17h 54m 15.1s (268.562820 deg.)
Dec = -26d 21' 56" (-26.365610 deg.)
Angular difference between Flight and Ground position is 4.146389 arcmin
Partial Coding Fraction: 1.015625 [ including projection effects ]
Duration
T90: 615.819999992847 +/- 70.9726322690693
Measured from: -76.6839999854565
to: 539.136000007391 [s; relative to TRIGTIME]
T50: 345.532000005245 +/- 87.9282662233362
Measured from: 51.1920000016689
to: 396.724000006914 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 548.303999990225
to: 549.303999990225 [s; relative to TRIGTIME]
Total Fluence
Measured from: -107.00799998641
to: 552.884000003338 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 2.681236 0.442121 0.058352 0.136164
0.143793 0.127161 0.107104 0.091046 [error]
Peak 0.030166 0.010745 0.008587 0.008076
0.010916 0.009798 0.009172 0.007283 [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 7.02e-07 2.64e-07 5.75e-08 1.50e-08 1.03e-06 1.04e-06 erg/cm2
Error 9.48e-08 6.67e-08 3.21e-08 1.48e-08 1.50e-07 1.54e-07 erg/cm2
Peak flux Power-law 2.32e-01 1.23e-01 4.09e-02 1.75e-02 4.06e-01 4.15e-01 ph/cm2/s
Error 2.00e-01 1.05e-01 6.87e-02 1.69e-01 3.21e-01 3.29e-01 ph/cm2/s
Fluence Cutoff-PL 7.50e-07 1.97e-07 2.83e-09 3.38e-13 9.50e-07 9.50e-07 erg/cm2
Error 1.15e-07 9.67e-08 3.39e-08 7.08e-09 1.32e-07 1.42e-07 erg/cm2
Peak flux Cutoff-PL 2.32e-01 1.23e-01 4.07e-02 1.73e-02 4.06e-01 4.13e-01 ph/cm2/s
Error 2.00e-01 1.05e-01 6.87e-02 1.68e-01 3.21e-01 3.28e-01 ph/cm2/s
Fluence Band 7.04e-07 1.82e-07 1.29e-08 2.06e-09 9.87e-07 8.42e-07 erg/cm2
Error 8.35e-08 8.18e-09 1.28e-07 0.00e+00 0.00e+00 0.00e+00 erg/cm2
Peak flux Band 1.64e-01 1.35e-01 6.94e-02 2.45e-02 4.13e-01 4.37e-01 ph/cm2/s
Error 6.70e-02 7.82e-02 5.60e-02 1.26e-01 1.82e-01 0.00e+00 ph/cm2/s
=== Time-averaged spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 4.200 0.459 - - 6.12e-05 2.66e-05 80.017 57
CPL 1.262 0.000 5.4 7.8 1.51e-02 0.00e+00 77.676 56
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 2.576 2.800 - - 1.96e-03 2.26e-03 66.222 57
CPL 2.108 3.536 42.1 5000.0 1.81e-03 3.98e+00 65.968 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 659.892 -107.008 552.884
T90 615.820 -76.684 539.136
T50 345.532 51.192 396.724
Peak 1.000 548.304 549.304
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
268.5628 -26.3656 0.0218 1.8 -133.0 1.9044 8.8 TRIG_00308224
------------------------------------------
Foreground time interval of the image:
-107.008 126.005 (delta_t = 233.013 [sec])
Background time interval of the image:
-239.000 -107.008 (delta_t = 131.992 [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 -107.008 sec. to 552.884 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 4.20047 ( -0.437283 0.480008 )
Norm@50keV : 6.122882E-05 ( -2.325828E-05 2.988444E-05) )
------------------------------------------------------------
Chi-Squared = 80.01726 using 59 PHA bins.
Reduced chi-squared = 1.403812 for 57 degrees of freedom
Null hypothesis probability = 2.386E-02
Photon flux (15-150 keV) in 659.9 sec: 4.507654E-02 ( -0.00583476 0.00583596 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.03352e-06 ( -1.4791e-07 1.52635e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -107.008 sec. to 552.884 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.26212 ( )
Epeak [keV] : 5.43859 ( -12.5197 3.09319 )
Norm@50keV : 1.509625E-02 ( )
------------------------------------------------------------
Chi-Squared = 77.67621 using 59 PHA bins.
Reduced chi-squared = 1.387075 for 56 degrees of freedom
Null hypothesis probability = 2.922E-02
Photon flux (15-150 keV) in 659.9 sec: 4.504650E-02 ( -0.00583145 0.00583226 ) ph/cm2/s
Energy fluence (15-150 keV) : 9.49728e-07 ( -1.33082e-07 1.30013e-07 ) ergs/cm2
Band function
Time interval is from -107.008 sec. to 552.884 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.45225 ( )
beta : -4.31425 ( )
Epeak [keV] : 15.1712 ( )
Norm@50keV : 1.016399E-03 ( )
------------------------------------------------------------
Chi-Squared = 123.8794 using 59 PHA bins.
Reduced chi-squared = 2.252353 for 55 degrees of freedom
Null hypothesis probability = 3.177E-07
Photon flux (15-150 keV) in 659.9 sec: 4.601804E-02 ( -0.00600663 0.00586076 ) ph/cm2/s
Energy fluence (15-150 keV) : 9.86616e-07 ( -1.29954e-07 1.2608e-07 ) ergs/cm2
Peak spectrum fit using the pre-slew DRM
Power-law model
Time interval is from 548.304 sec. to 549.304 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.57634 ( -2.23152 3.36924 )
Norm@50keV : 1.960691E-03 ( -1.960691E-03 2.567673E-03) )
------------------------------------------------------------
Chi-Squared = 66.22217 using 59 PHA bins.
Reduced chi-squared = 1.161792 for 57 degrees of freedom
Null hypothesis probability = 0.189
Photon flux (15-150 keV) in 1.000 sec: 0.405944 ( -0.405944 0.235774 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.00258e-08 ( -1.47826e-08 2.31899e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 548.304 sec. to 549.304 sec.
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.10759 ( -4.94691 2.12539 )
Epeak [keV] : 42.0820 ( -42.0703 9957.92 )
Norm@50keV : 1.811655E-03 ( -1.811655E-03 7.95833 )
------------------------------------------------------------
Chi-Squared = 65.96796 using 59 PHA bins.
but latest trial -5.81351 gives Chi-Squared = 1.53491
Reduced chi-squared = 1.177999 for 56 degrees of freedom
Null hypothesis probability = 0.170
Photon flux (15-150 keV) in 1.000 sec: 0.405617 ( -0.405617 0.235748 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.99997e-08 ( -1.99997e-08 2.31832e-08 ) ergs/cm2
Band function
Time interval is from 548.304 sec. to 549.304 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.38168 ( -1.306534E-04 14.9999 )
beta : -1.61954 ( -3.40078 2.19950 )
Epeak [keV] : 6.10982 ( -6.00982 9993.89 )
Norm@50keV : 7.970820E-03 ( -0.273875 0.341624 )
------------------------------------------------------------
Chi-Squared = 66.93564 using 59 PHA bins.
Reduced chi-squared = 1.217012 for 55 degrees of freedom
Null hypothesis probability = 0.130
Photon flux (15-150 keV) in 1.000 sec: 0.413066 ( -0.129635 0.234128 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.02126e-08 ( -1.49401e-08 1.53029e-08 ) ergs/cm2
Plot creation:
Wed Apr 2 21:52:09 EDT 2008