batgrbproduct Analysis for Trigger=255445
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): Thu Dec 13 10:58:15 EST 2007
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger255445/GCN5_download_cron
======================================================================
Trigger: 00255445 Segment: 000
BAT Trigger Time: 190106563.264 [s; MET]
Trigger Stop: 190106566.336 [s; MET]
UTC: 2007-01-10T07:22:41.574460 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 0.910178868837273 Dec: -52.9610973406944 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 10.23
Image Trigger?: NO
Rate S/N Ratio: 9.69535971483266 [ if not an image trigger ]
Image S/N Ratio: 10.23
Flight Position: [ source = BAT ]
RA: 0.910178868837273 Dec: -52.9610973406944 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 0.924597187395145 Dec: -52.9737642631847 [deg; J2000]
{ 00h 03m 41.9s , -52d 58' 25.6" }
+/- 1.15367253451586 [arcmin] (estimated 90% radius based on SNR)
+/- 0.338564726316806 [arcmin] (formal 1-sigma fit error)
SNR: 24.7987058840151
RA = 0h 3m 41.9s (0.924597 deg.)
Dec = -52d 58' 26" (-52.973764 deg.)
Angular difference between Flight and Ground position is 0.921459 arcmin
Partial Coding Fraction: 0.9765625 [ including projection effects ]
Duration
T90: 88.4160000085831 +/- 14.4780330174947
Measured from: -0.388000011444092
to: 88.027999997139 [s; relative to TRIGTIME]
T50: 30.2479999959469 +/- 5.84655522874835
Measured from: 9.77200001478195
to: 40.0200000107288 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: -0.159999996423721
to: 0.840000003576279 [s; relative to TRIGTIME]
Total Fluence
Measured from: -2.74399998784065
to: 108.175999999046 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.833805 0.976814 0.710297 0.173371
0.051089 0.051185 0.045693 0.041352 [error]
Peak 0.023422 0.031811 0.013441 0.008325
0.005281 0.005105 0.004599 0.004021 [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 2.41e-07 4.20e-07 5.59e-07 1.52e-06 1.63e-06 2.74e-06 erg/cm2
Error 2.68e-08 2.66e-08 4.67e-08 2.85e-07 1.09e-07 3.16e-07 erg/cm2
Peak flux Power-law 2.24e-01 2.02e-01 1.26e-01 1.19e-01 6.02e-01 6.71e-01 ph/cm2/s
Error 7.45e-02 4.22e-02 3.85e-02 7.49e-02 1.24e-01 1.41e-01 ph/cm2/s
Fluence Cutoff-PL 2.41e-07 4.20e-07 5.59e-07 1.51e-06 1.63e-06 2.60e-06 erg/cm2
Error 2.68e-08 2.66e-08 4.67e-08 2.83e-07 1.09e-07 4.76e-07 erg/cm2
Peak flux Cutoff-PL 2.24e-01 2.02e-01 1.26e-01 1.19e-01 6.02e-01 6.70e-01 ph/cm2/s
Error 7.45e-02 4.22e-02 3.86e-02 7.44e-02 1.24e-01 1.41e-01 ph/cm2/s
Fluence Band 2.36e-07 4.17e-07 5.60e-07 1.53e-06 1.63e-06 2.78e-06 erg/cm2
Error 1.85e-08 2.59e-08 1.05e-07 1.52e-07 8.47e-07 1.64e-07 erg/cm2
Peak flux Band 6.70e-01 0.00e+00 0.00e+00 0.00e+00 0.00e+00 0.00e+00 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
=== Time-averaged spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.587 0.118 - - 1.57e-03 9.61e-05 50.513 57
CPL 1.561 0.219 899.2 0.0 1.61e-03 3.60e-04 50.652 56
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.683 0.395 - - 4.56e-03 1.06e-03 49.629 57
CPL 1.682 0.400 9985.7 5000.0 4.57e-03 1.07e-03 49.630 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: 42.624000 sec.
T50 in the 50-300 keV band: 22.400000 sec.
=== Table of the duration information ==
Value tstart tstop
T100 110.920 -2.744 108.176
T90 88.416 -0.388 88.028
T50 30.248 9.772 40.020
Peak 1.000 -0.160 0.840
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
0.9246 -52.9738 0.0077 20.9 -11.1 1.9795 24.8 TRIG_00255445
------------------------------------------
Foreground time interval of the image:
-2.744 39.237 (delta_t = 41.981 [sec])
Background time interval of the image:
-57.863 -2.744 (delta_t = 55.119 [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 -2.744 sec. to 108.176 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.58711 ( -0.117582 0.118214 )
Norm@50keV : 1.567782E-03 ( -9.642635E-05 9.583542E-05) )
------------------------------------------------------------
Chi-Squared = 50.51276 using 59 PHA bins.
Reduced chi-squared = 0.8861887 for 57 degrees of freedom
Null hypothesis probability = 0.715
Photon flux (15-150 keV) in 110.9 sec: 0.200671 ( -0.012495 0.012545 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.62864e-06 ( -1.0846e-07 1.09248e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -2.744 sec. to 108.176 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.56076 ( -0.291374 0.146158 )
Epeak [keV] : 899.153 ( )
Norm@50keV : 1.612941E-03 ( -9.979482E-05 6.209434E-04) )
------------------------------------------------------------
Chi-Squared = 50.65192 using 59 PHA bins.
Reduced chi-squared = 0.9044986 for 56 degrees of freedom
Null hypothesis probability = 0.677
Photon flux (15-150 keV) in 110.9 sec: 0.200581 ( -0.01249 0.01254 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.62882e-06 ( -1.08593e-07 1.09181e-07 ) ergs/cm2
Band function
Time interval is from -2.744 sec. to 108.176 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.21463 ( -8.76537 6.23463 )
beta : -1.58464 ( -0.122518 0.113299 )
Epeak [keV] : 40.3424 ( -17.7019 1610.66 )
Norm@50keV : 3.250900E-03 ( -4.194135E-03 0.172711 )
------------------------------------------------------------
Chi-Squared = 50.54932 using 59 PHA bins.
Reduced chi-squared = 0.9190786 for 55 degrees of freedom
Null hypothesis probability = 0.645
Photon flux (15-150 keV) in 110.9 sec: 0.200650 ( -0.01188 0.012271 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.63001e-06 ( -1.10445e-07 1.58266e-06 ) ergs/cm2
Peak spectrum fit using the pre-slew DRM
Power-law model
Time interval is from -0.160 sec. to 0.840 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.68326 ( -0.383768 0.405659 )
Norm@50keV : 4.557837E-03 ( -1.081952E-03 1.035338E-03) )
------------------------------------------------------------
Chi-Squared = 49.62946 using 59 PHA bins.
Reduced chi-squared = 0.8706922 for 57 degrees of freedom
Null hypothesis probability = 0.745
Photon flux (15-150 keV) in 1.000 sec: 0.601835 ( -0.124259 0.124374 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.22381e-08 ( -1.02631e-08 1.06393e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.160 sec. to 0.840 sec.
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.68186 ( -0.393150 0.407502 )
Epeak [keV] : 9985.73 ( -9985.72 14.2715 )
Norm@50keV : 4.566489E-03 ( -1.089301E-03 1.041708E-03) )
------------------------------------------------------------
Chi-Squared = 49.63024 using 59 PHA bins.
but latest trial 1.29592 gives Chi-Squared = 0.394875
Reduced chi-squared = 0.8862543 for 56 degrees of freedom
Null hypothesis probability = 0.713
Photon flux (15-150 keV) in 1.000 sec: 0.601642 ( -0.124219 0.124337 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.22492e-08 ( -1.02697e-08 1.06333e-08 ) ergs/cm2
Band function
Time interval is from -0.160 sec. to 0.840 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.24311 ( -8.59689 6.40311 )
beta : -1.70028 ( -8.33064 0.370319 )
Epeak [keV] : 42.8053 ( -24.7447 9975.16 )
Norm@50keV : 9.748204E-03 ( -8.859850E-03 0.741176 )
------------------------------------------------------------
Chi-Squared = 49.64752 using 59 PHA bins.
Reduced chi-squared = 0.9026821 for 55 degrees of freedom
Null hypothesis probability = 0.679
Photon flux (15-150 keV) in 1.000 sec: ( ) ph/cm2/s
Energy fluence (15-150 keV) : 0 ( 0 0 ) ergs/cm2
Plot creation:
Thu Dec 13 11:27:27 EST 2007