batgrbproduct Analysis for Trigger=176620
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): Sat Dec 29 18:42:50 EST 2007
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger176620/SDC
======================================================================
Trigger: 00176620 Segment: 000
BAT Trigger Time: 158518482.176 [s; MET]
Trigger Stop: 158518490.368 [s; MET]
UTC: 2006-01-09T16:54:41.230260 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 282.709997814732 Dec: 31.9895994348777 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 7.1
Image Trigger?: NO
Rate S/N Ratio: 10.9087121146357 [ if not an image trigger ]
Image S/N Ratio: 7.1
Flight Position: [ source = BAT ]
RA: 282.709997814732 Dec: 31.9895994348777 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 282.737847414675 Dec: 32.0118226295464 [deg; J2000]
{ 18h 50m 57.1s , +32d 00' 42.6" }
+/- 2.99108083219458 [arcmin] (estimated 90% radius based on SNR)
+/- 1.72016101472721 [arcmin] (formal 1-sigma fit error)
SNR: 6.35863476778227
RA = 18h 50m 57.1s (282.737847 deg.)
Dec = 32d 0' 43" (32.011823 deg.)
Angular difference between Flight and Ground position is 1.945760 arcmin
Partial Coding Fraction: 0.921875 [ including projection effects ]
Duration
T90: 115.432000011206 +/- 10.9745261292203
Measured from: 1.43599998950958
to: 116.868000000715 [s; relative to TRIGTIME]
T50: 82.9000000059605 +/- 16.6602158190628
Measured from: 12.5600000023842
to: 95.4600000083447 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 90.1879999935627
to: 91.1879999935627 [s; relative to TRIGTIME]
Total Fluence
Measured from: -0.995999991893768
to: 126.759999990463 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.430976 0.492729 0.274388 0.022159
0.055247 0.055414 0.047497 0.040005 [error]
Peak 0.016148 0.022851 0.016463 0.006884
0.005011 0.005079 0.004413 0.003503 [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 1.39e-07 1.97e-07 2.07e-07 4.01e-07 6.69e-07 9.48e-07 erg/cm2
Error 2.59e-08 2.54e-08 4.59e-08 1.78e-07 1.05e-07 2.27e-07 erg/cm2
Peak flux Power-law 1.68e-01 1.60e-01 1.06e-01 1.10e-01 4.80e-01 5.45e-01 ph/cm2/s
Error 6.51e-02 4.04e-02 3.55e-02 7.33e-02 1.18e-01 1.37e-01 ph/cm2/s
Fluence Cutoff-PL 1.33e-07 2.10e-07 2.05e-07 1.73e-07 6.39e-07 7.23e-07 erg/cm2
Error 2.86e-08 3.40e-08 5.14e-08 2.49e-07 1.16e-07 3.01e-07 erg/cm2
Peak flux Cutoff-PL 1.46e-01 1.78e-01 1.13e-01 4.02e-02 4.65e-01 4.77e-01 ph/cm2/s
Error 7.64e-02 5.27e-02 4.25e-02 8.63e-02 1.22e-01 1.55e-01 ph/cm2/s
Fluence Band 1.31e-07 2.09e-07 2.05e-07 1.73e-07 6.38e-07 7.16e-07 erg/cm2
Error 2.83e-08 3.40e-08 5.13e-08 2.29e-07 1.17e-07 3.00e-07 erg/cm2
Peak flux Band 1.46e-01 1.78e-01 1.13e-01 4.03e-02 4.65e-01 4.77e-01 ph/cm2/s
Error 7.68e-02 4.12e-02 4.25e-02 8.59e-02 1.22e-01 1.37e-01 ph/cm2/s
=== Time-averaged spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.928 0.247 - - 5.69e-04 9.15e-05 75.493 57
CPL 1.229 0.000 47.6 5000.0 1.41e-03 2.36e-03 74.656 56
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.593 0.426 - - 3.74e-03 9.87e-04 48.592 57
CPL 0.617 2.054 67.1 5000.0 1.23e-02 1.34e-01 47.645 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: 31.360000 sec.
T50 in the 50-300 keV band: 16.192000 sec.
=== Table of the duration information ==
Value tstart tstop
T100 127.756 -0.996 126.760
T90 115.432 1.436 116.868
T50 82.900 12.560 95.460
Peak 1.000 90.188 91.188
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
282.7378 +32.0118 0.0302 18.2 -44.3 0.4684 6.4 TRIG_00176620
------------------------------------------
Foreground time interval of the image:
-0.996 54.029 (delta_t = 55.025 [sec])
Background time interval of the image:
-299.176 -0.996 (delta_t = 298.180 [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 -0.996 sec. to 126.760 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.92815 ( -0.238504 0.254557 )
Norm@50keV : 5.693019E-04 ( -9.283915E-05 9.008497E-05) )
------------------------------------------------------------
Chi-Squared = 75.49346 using 59 PHA bins.
Reduced chi-squared = 1.324447 for 57 degrees of freedom
Null hypothesis probability = 5.105E-02
Photon flux (15-150 keV) in 127.8 sec: 8.269466E-02 ( -0.0106395 0.0106422 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.69168e-07 ( -1.03794e-07 1.06639e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.996 sec. to 126.760 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.22858 ( )
Epeak [keV] : 47.5845 ( -48.5592 9951.43 )
Norm@50keV : 1.412676E-03 ( -1.076283E-03 3.645273E-03) )
------------------------------------------------------------
Chi-Squared = 74.65574 using 59 PHA bins.
Reduced chi-squared = 1.333138 for 56 degrees of freedom
Null hypothesis probability = 4.851E-02
Photon flux (15-150 keV) in 127.8 sec: 8.120176E-02 ( -0.0109468 0.0109119 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.38663e-07 ( -1.1472e-07 1.17111e-07 ) ergs/cm2
Band function
Time interval is from -0.996 sec. to 126.760 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.42038 ( -8.57962 1.01368 )
beta : -8.62326 ( -1.37674 6.88822 )
Epeak [keV] : 49.2493 ( -20.5416 9950.75 )
Norm@50keV : 1.104278E-03 ( -1.104278E-03 3.616367E-03) )
------------------------------------------------------------
Chi-Squared = 74.54893 using 59 PHA bins.
Reduced chi-squared = 1.355435 for 55 degrees of freedom
Null hypothesis probability = 4.077E-02
Photon flux (15-150 keV) in 127.8 sec: 8.120212E-02 ( -0.0109473 0.0109385 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.37831e-07 ( -1.14562e-07 1.18763e-07 ) ergs/cm2
Peak spectrum fit using the pre-slew DRM
Power-law model
Time interval is from 90.188 sec. to 91.188 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.59322 ( -0.415032 0.437750 )
Norm@50keV : 3.743449E-03 ( -1.000185E-03 9.729855E-04) )
------------------------------------------------------------
Chi-Squared = 48.59188 using 59 PHA bins.
Reduced chi-squared = 0.8524891 for 57 degrees of freedom
Null hypothesis probability = 0.778
Photon flux (15-150 keV) in 1.000 sec: 0.480031 ( -0.118294 0.118452 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.50242e-08 ( -9.7834e-09 1.01339e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 90.188 sec. to 91.188 sec.
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.616535 ( -2.55703 1.55050 )
Epeak [keV] : 67.0719 ( -67.0619 9932.93 )
Norm@50keV : 1.231493E-02 ( -1.231493E-02 0.256141 )
------------------------------------------------------------
Chi-Squared = 47.64513 using 59 PHA bins.
but latest trial 2.16817 gives Chi-Squared = 2.73300
Reduced chi-squared = 0.8508058 for 56 degrees of freedom
Null hypothesis probability = 0.779
Photon flux (15-150 keV) in 1.000 sec: 0.465223 ( -0.122144 0.121563 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.26732e-08 ( -1.02123e-08 1.09768e-08 ) ergs/cm2
Band function
Time interval is from 90.188 sec. to 91.188 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.620099 ( -1.32012 1.02834 )
beta : -9.24365 ( -0.756347 7.98331 )
Epeak [keV] : 67.1164 ( -26.6733 9932.88 )
Norm@50keV : 1.226361E-02 ( -1.226361E-02 0.435176 )
------------------------------------------------------------
Chi-Squared = 47.64515 using 59 PHA bins.
Reduced chi-squared = 0.8662755 for 55 degrees of freedom
Null hypothesis probability = 0.749
Photon flux (15-150 keV) in 1.000 sec: 0.465285 ( -0.122191 0.121522 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.26752e-08 ( -1.01563e-08 1.09491e-08 ) ergs/cm2
Plot creation:
Sat Dec 29 18:56:38 EST 2007