batgrbproduct Analysis for Trigger=227996
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 Jan 2 02:33:17 EST 2008
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger227996/GCN5_download_cron
======================================================================
Trigger: 00227996 Segment: 000
BAT Trigger Time: 179024602.624 [s; MET]
Trigger Stop: 179024603.648 [s; MET]
UTC: 2006-09-04T01:03:21.201840 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 237.743100468034 Dec: 44.9659595410251 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 7.71
Image Trigger?: NO
Rate S/N Ratio: 12.1243556529821 [ if not an image trigger ]
Image S/N Ratio: 7.71
Flight Position: [ source = BAT ]
RA: 237.743100468034 Dec: 44.9659595410251 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 237.733068507175 Dec: 44.9862869962562 [deg; J2000]
{ 15h 50m 55.9s , +44d 59' 10.6" }
+/- 1.54668079952622 [arcmin] (estimated 90% radius based on SNR)
+/- 0.611249007156433 [arcmin] (formal 1-sigma fit error)
SNR: 16.3134553886682
RA = 15h 50m 55.9s (237.733069 deg.)
Dec = 44d 59' 11" (44.986287 deg.)
Angular difference between Flight and Ground position is 1.291837 arcmin
Partial Coding Fraction: 0.9375 [ including projection effects ]
Duration
T90: 80.1040000319481 +/- 2.32823364432951
Measured from: -0.968000024557114
to: 79.136000007391 [s; relative to TRIGTIME]
T50: 25.9079999923706 +/- 1.9108866812029
Measured from: 34.4799999892712
to: 60.3879999816418 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 55.339999973774
to: 56.339999973774 [s; relative to TRIGTIME]
Total Fluence
Measured from: -23.8880000114441
to: 108.619999974966 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 3.842968 4.816388 3.499174 0.772879
0.057715 0.059689 0.054080 0.047274 [error]
Peak 0.147505 0.214622 0.215300 0.058469
0.006717 0.007760 0.007655 0.005610 [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 1.08e-06 1.95e-06 2.72e-06 7.90e-06 7.81e-06 1.36e-05 erg/cm2
Error 4.92e-08 4.92e-08 6.24e-08 4.55e-07 1.53e-07 4.69e-07 erg/cm2
Peak flux Power-law 1.19e+00 1.51e+00 1.40e+00 2.29e+00 4.87e+00 6.39e+00 ph/cm2/s
Error 1.02e-01 7.59e-02 6.15e-02 2.30e-01 2.00e-01 2.68e-01 ph/cm2/s
Fluence Cutoff-PL 1.04e-06 1.96e-06 2.75e-06 6.85e-06 7.75e-06 1.22e-05 erg/cm2
Error 7.21e-08 4.91e-08 5.72e-08 1.29e-06 1.75e-07 0.00e+00 erg/cm2
Peak flux Cutoff-PL 1.18e+00 1.51e+00 1.40e+00 2.27e+00 4.87e+00 6.37e+00 ph/cm2/s
Error 1.02e-01 7.60e-02 6.16e-02 2.29e-01 2.00e-01 2.67e-01 ph/cm2/s
Fluence Band 0.00e+00 0.00e+00 0.00e+00 0.00e+00 0.00e+00 0.00e+00 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 Band 1.18e+00 1.51e+00 1.40e+00 2.27e+00 4.87e+00 6.37e+00 ph/cm2/s
Error 1.02e-01 5.73e-02 6.16e-02 2.29e-01 2.00e-01 2.67e-01 ph/cm2/s
=== Time-averaged spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.523 0.041 - - 6.24e-03 1.21e-04 45.566 57
CPL 1.389 0.164 268.2 4923.9 7.10e-03 1.09e-03 43.960 0
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.106 0.075 - - 4.20e-02 1.65e-03 65.503 57
CPL 1.047 0.178 965.2 0.0 4.46e-02 1.65e-03 65.685 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: 74.048000 sec.
T50 in the 50-300 keV band: 22.272000 sec.
=== Table of the duration information ==
Value tstart tstop
T100 132.508 -23.888 108.620
T90 80.104 -0.968 79.136
T50 25.908 34.480 60.388
Peak 1.000 55.340 56.340
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
237.7331 +44.9863 0.0117 13.7 132.6 1.6080 16.3 TRIG_00227996
------------------------------------------
Foreground time interval of the image:
-23.888 14.277 (delta_t = 38.165 [sec])
Background time interval of the image:
-47.623 -23.888 (delta_t = 23.735 [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 -23.888 sec. to 108.620 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.52321 ( -4.128277E-02 4.128277E-02) )
Norm@50keV : 6.236782E-03 ( -1.215185E-04 1.214580E-04) )
------------------------------------------------------------
Chi-Squared = 45.56607 using 59 PHA bins.
Reduced chi-squared = 0.7994048 for 57 degrees of freedom
Null hypothesis probability = 0.862
Photon flux (15-150 keV) in 132.5 sec: 0.783556 ( -0.018688 0.018814 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.81074e-06 ( -1.53488e-07 1.53395e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -23.888 sec. to 108.620 sec.
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.38863 ( -0.169013 0.159042 )
Epeak [keV] : 268.173 ( -115.955 9731.83 )
Norm@50keV : 7.100334E-03 ( -9.442260E-04 1.225987E-03) )
------------------------------------------------------------
Chi-Squared = 43.96004 using 59 PHA bins.
but latest trial 6.296546E-03 gives Chi-Squared = 1.85981
Reduced chi-squared = 0.7850008 for 56 degrees of freedom
Null hypothesis probability = 0.878
Photon flux (15-150 keV) in 132.5 sec: 0.773010 ( -0.022797 0.022226 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.75244e-06 ( -1.8179e-07 1.67241e-07 ) ergs/cm2
Band function
Time interval is from -23.888 sec. to 108.620 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.19699 ( -8.80301 5.25116 )
beta : -1.52479 ( -8.12926 0.373827 )
Epeak [keV] : 58.7518 ( -286.010 9713.89 )
Norm@50keV : 1.101747E-02 ( -8.584084E-04 76479.4 )
------------------------------------------------------------
Chi-Squared = 45.48241 using 59 PHA bins.
Reduced chi-squared = 0.8269529 for 55 degrees of freedom
Null hypothesis probability = 0.816
Photon flux (15-150 keV) in 132.5 sec: 0.773068 ( -0.022858 0.021577 ) ph/cm2/s
Energy fluence (15-150 keV) : 0 ( 0 0 ) ergs/cm2
Peak spectrum fit using the pre-slew DRM
Power-law model
Time interval is from 55.340 sec. to 56.340 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.10649 ( -7.560074E-02 7.529724E-02) )
Norm@50keV : 4.198594E-02 ( -1.648910E-03 1.646306E-03) )
------------------------------------------------------------
Chi-Squared = 65.50271 using 59 PHA bins.
Reduced chi-squared = 1.149170 for 57 degrees of freedom
Null hypothesis probability = 0.206
Photon flux (15-150 keV) in 1.000 sec: 4.87315 ( -0.19937 0.19994 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.38055e-07 ( -1.8779e-08 1.8876e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 55.340 sec. to 56.340 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.04655 ( -0.223713 0.132929 )
Epeak [keV] : 965.159 ( )
Norm@50keV : 4.455722E-02 ( -1.654085E-03 1.650881E-03) )
------------------------------------------------------------
Chi-Squared = 65.68541 using 59 PHA bins.
Reduced chi-squared = 1.172954 for 56 degrees of freedom
Null hypothesis probability = 0.176
Photon flux (15-150 keV) in 1.000 sec: 4.87133 ( -0.19933 0.19985 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.38168e-07 ( -1.8775e-08 1.8909e-08 ) ergs/cm2
Band function
Time interval is from 55.340 sec. to 56.340 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.880879 ( -10.2507 2.15917 )
beta : -1.10649 ( -7.725799E-02 7.634580E-02) )
Epeak [keV] : 61.6826 ( -31.0767 207.909 )
Norm@50keV : 7.201484E-02 ( -0.616975 13560.9 )
------------------------------------------------------------
Chi-Squared = 65.50272 using 59 PHA bins.
Reduced chi-squared = 1.190958 for 55 degrees of freedom
Null hypothesis probability = 0.157
Photon flux (15-150 keV) in 1.000 sec: 4.87132 ( -0.19932 0.19985 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.37892e-07 ( -1.8793e-08 1.8854e-08 ) ergs/cm2
Plot creation:
Wed Jan 2 02:58:08 EST 2008