batgrbproduct Analysis for Trigger=252588
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 17:12:54 EST 2008
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger252588/SDC
======================================================================
Trigger: 00252588 Segment: 000
BAT Trigger Time: 188450933.76 [s; MET]
Trigger Stop: 188450937.856 [s; MET]
UTC: 2006-12-22T03:28:52.110840 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 358.243358155449 Dec: 46.5262619462849 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 7.21
Image Trigger?: NO
Rate S/N Ratio: 13.3790881602597 [ if not an image trigger ]
Image S/N Ratio: 7.21
Flight Position: [ source = BAT ]
RA: 358.243358155449 Dec: 46.5262619462849 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 358.258734824257 Dec: 46.5140823857324 [deg; J2000]
{ 23h 53m 02.1s , +46d 30' 50.7" }
+/- 1.35042785693989 [arcmin] (estimated 90% radius based on SNR)
+/- 0.489233379155699 [arcmin] (formal 1-sigma fit error)
SNR: 19.802986102959
RA = 23h 53m 2.1s (358.258735 deg.)
Dec = 46d 30' 51" (46.514082 deg.)
Angular difference between Flight and Ground position is 0.968015 arcmin
Partial Coding Fraction: 0.703125 [ including projection effects ]
Duration
T90: 96 +/- 16
Measured from: 0.240000009536743
to: 96.2400000095367 [s; relative to TRIGTIME]
T50: 16 +/- 16
Measured from: 64.2400000095367
to: 80.2400000095367 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 87.7400000095367
to: 88.7400000095367 [s; relative to TRIGTIME]
Total Fluence
Measured from: -15.7599999904633
to: 112.240000009537 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 3.185902 4.484800 3.742085 0.983701
0.062134 0.064520 0.058008 0.047429 [error]
Peak 1.493786 2.432849 2.330172 0.607544
0.024019 0.027411 0.026755 0.019805 [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 9.89e-07 1.95e-06 2.99e-06 9.99e-06 8.37e-06 1.59e-05 erg/cm2
Error 4.67e-08 5.22e-08 6.63e-08 5.54e-07 1.68e-07 5.66e-07 erg/cm2
Peak flux Power-law 9.62e-01 1.14e+00 9.79e-01 1.43e+00 3.59e+00 4.51e+00 ph/cm2/s
Error 3.97e-02 2.80e-02 1.71e-02 5.76e-02 7.20e-02 7.53e-02 ph/cm2/s
Fluence Cutoff-PL 9.61e-07 1.95e-06 3.02e-06 9.00e-06 8.33e-06 1.49e-05 erg/cm2
Error 6.60e-08 4.98e-08 7.67e-08 1.47e-06 1.35e-07 1.48e-06 erg/cm2
Peak flux Cutoff-PL 8.52e-01 1.14e+00 1.02e+00 1.10e+00 3.49e+00 4.11e+00 ph/cm2/s
Error 5.73e-02 2.89e-02 2.36e-02 1.20e-01 8.07e-02 1.58e-01 ph/cm2/s
Fluence Band 9.53e-07 1.95e-06 3.01e-06 8.99e-06 8.32e-06 1.47e-05 erg/cm2
Error 6.53e-08 5.27e-08 8.25e-08 1.47e-06 1.80e-07 1.10e-06 erg/cm2
Peak flux Band 8.52e-01 1.14e+00 1.02e+00 1.10e+00 3.49e+00 4.42e+00 ph/cm2/s
Error 5.74e-02 2.89e-02 2.37e-02 1.20e-01 8.10e-02 0.00e+00 ph/cm2/s
=== Time-averaged spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.385 0.041 - - 6.74e-03 1.37e-04 42.406 57
CPL 1.284 0.146 429.0 5000.0 7.41e-03 1.01e-03 41.541 0
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.222 0.033 - - 3.05e-02 5.42e-04 51.452 57
CPL 0.884 0.148 210.7 74.1 4.13e-02 5.42e-03 34.858 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: 66.752000 sec.
T50 in the 50-300 keV band: 15.104000 sec.
=== Table of the duration information ==
Value tstart tstop
T100 128.000 -15.760 112.240
T90 96.000 0.240 96.240
T50 16.000 64.240 80.240
Peak 1.000 87.740 88.740
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
358.2587 +46.5141 0.0097 28.1 -136.1 1.8401 19.8 TRIG_00252588
------------------------------------------
Foreground time interval of the image:
-15.760 40.845 (delta_t = 56.605 [sec])
Background time interval of the image:
-239.760 -15.760 (delta_t = 224.000 [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 -15.760 sec. to 112.240 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.38476 ( -4.064107E-02 4.052746E-02) )
Norm@50keV : 6.742119E-03 ( -1.375796E-04 1.373570E-04) )
------------------------------------------------------------
Chi-Squared = 42.40638 using 59 PHA bins.
Reduced chi-squared = 0.7439716 for 57 degrees of freedom
Null hypothesis probability = 0.925
Photon flux (15-150 keV) in 128.0 sec: 0.818269 ( -0.019731 0.019836 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.36627e-06 ( -1.69114e-07 1.67104e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -15.760 sec. to 112.240 sec.
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.28377 ( -0.159945 0.131510 )
Epeak [keV] : 428.974 ( -428.964 9571.03 )
Norm@50keV : 7.408045E-03 ( -8.327155E-04 1.187906E-03) )
------------------------------------------------------------
Chi-Squared = 41.54098 using 59 PHA bins.
but latest trial 6.770328E-03 gives Chi-Squared = 0.793026
Reduced chi-squared = 0.7418032 for 56 degrees of freedom
Null hypothesis probability = 0.925
Photon flux (15-150 keV) in 128.0 sec: 0.811447 ( -0.011552 0.021858 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.33046e-06 ( -9.08032e-08 1.78202e-07 ) ergs/cm2
Band function
Time interval is from -15.760 sec. to 112.240 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.02111 ( -8.97889 2.50263 )
beta : -1.38686 ( -8.41202 0.235712 )
Epeak [keV] : 67.5149 ( -479.129 9520.77 )
Norm@50keV : 1.249183E-02 ( -4.860396E-04 132.716 )
------------------------------------------------------------
Chi-Squared = 42.35683 using 59 PHA bins.
Reduced chi-squared = 0.7701241 for 55 degrees of freedom
Null hypothesis probability = 0.894
Photon flux (15-150 keV) in 128.0 sec: 0.811332 ( -0.022887 0.023003 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.32315e-06 ( -1.81965e-07 1.77946e-07 ) ergs/cm2
Peak spectrum fit using the pre-slew DRM
Power-law model
Time interval is from 80.240 sec. to 96.240 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.22178 ( -3.323352E-02 3.312504E-02) )
Norm@50keV : 3.048709E-02 ( -5.425625E-04 5.414654E-04) )
------------------------------------------------------------
Chi-Squared = 51.45208 using 59 PHA bins.
Reduced chi-squared = 0.9026681 for 57 degrees of freedom
Null hypothesis probability = 0.682
Photon flux (15-150 keV) in 16.00 sec: 3.58991 ( -0.07184 0.07212 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.91907e-06 ( -8.3424e-08 8.3264e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 80.240 sec. to 96.240 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.884323 ( -0.153327 0.141794 )
Epeak [keV] : 210.670 ( -45.9166 102.373 )
Norm@50keV : 4.132410E-02 ( -4.852194E-03 5.982649E-03) )
------------------------------------------------------------
Chi-Squared = 34.85776 using 59 PHA bins.
Reduced chi-squared = 0.6224600 for 56 degrees of freedom
Null hypothesis probability = 0.988
Photon flux (15-150 keV) in 16.00 sec: 3.49222 ( -0.08046 0.08088 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.86278e-06 ( -8.7984e-08 8.7552e-08 ) ergs/cm2
Band function
Time interval is from 80.240 sec. to 96.240 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.880984 ( -0.145001 0.149949 )
beta : -8.86027 ( -1.13973 7.45559 )
Epeak [keV] : 209.156 ( -44.4209 103.763 )
Norm@50keV : 4.145355E-02 ( -4.983015E-03 5.850345E-03) )
------------------------------------------------------------
Chi-Squared = 34.85653 using 59 PHA bins.
Reduced chi-squared = 0.6337551 for 55 degrees of freedom
Null hypothesis probability = 0.985
Photon flux (15-150 keV) in 16.00 sec: 3.49210 ( -0.08066 0.08125 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.85939e-06 ( -8.7872e-08 8.7456e-08 ) ergs/cm2
Plot creation:
Wed Jan 2 17:40:59 EST 2008