batgrbproduct Analysis for Trigger=176818
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): Mon Dec 31 08:56:12 EST 2007
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger176818/SDC
======================================================================
Trigger: 00176818 Segment: 000
BAT Trigger Time: 158646187.072 [s; MET]
Trigger Stop: 158646187.584 [s; MET]
UTC: 2006-01-11T04:23:06.123420 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 276.212529459245 Dec: 37.6021981979871 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 7.47
Image Trigger?: NO
Rate S/N Ratio: 13.490737563232 [ if not an image trigger ]
Image S/N Ratio: 7.47
Flight Position: [ source = BAT ]
RA: 276.212529459245 Dec: 37.6021981979871 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 276.197841767289 Dec: 37.6025566787104 [deg; J2000]
{ 18h 24m 47.5s , +37d 36' 09.2" }
+/- 0.745167922406025 [arcmin] (estimated 90% radius based on SNR)
+/- 0.176203201094378 [arcmin] (formal 1-sigma fit error)
SNR: 46.303353899396
RA = 18h 24m 47.5s (276.197842 deg.)
Dec = 37d 36' 9" (37.602557 deg.)
Angular difference between Flight and Ground position is 0.698523 arcmin
Partial Coding Fraction: 0.9765625 [ including projection effects ]
Duration
T90: 13.2200000286102 +/- 1.15467742377442
Measured from: 0.42399999499321
to: 13.6440000236034 [s; relative to TRIGTIME]
T50: 5.86800000071526 +/- 0.370621082343099
Measured from: 3.11599999666214
to: 8.9839999973774 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 4.3120000064373
to: 5.3120000064373 [s; relative to TRIGTIME]
Total Fluence
Measured from: -0.65200001001358
to: 17.5760000050068 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.595927 0.850770 0.545648 0.082720
0.022919 0.024034 0.020888 0.017208 [error]
Peak 0.050848 0.088571 0.062827 0.015332
0.005658 0.006080 0.005331 0.004204 [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 2.01e-07 3.37e-07 4.31e-07 1.11e-06 1.27e-06 2.07e-06 erg/cm2
Error 1.35e-08 1.34e-08 2.12e-08 1.19e-07 5.05e-08 1.36e-07 erg/cm2
Peak flux Power-law 5.43e-01 5.79e-01 4.37e-01 5.38e-01 1.76e+00 2.10e+00 ph/cm2/s
Error 7.57e-02 5.04e-02 4.32e-02 1.08e-01 1.44e-01 1.72e-01 ph/cm2/s
Fluence Cutoff-PL 1.74e-07 3.58e-07 4.46e-07 4.32e-07 1.20e-06 1.43e-06 erg/cm2
Error 1.67e-08 1.61e-08 2.38e-08 1.54e-07 5.83e-08 1.64e-07 erg/cm2
Peak flux Cutoff-PL 4.62e-01 6.29e-01 4.72e-01 2.25e-01 1.71e+00 1.79e+00 ph/cm2/s
Error 9.10e-02 6.30e-02 5.17e-02 1.32e-01 1.49e-01 1.95e-01 ph/cm2/s
Fluence Band 1.74e-07 3.58e-07 4.41e-07 6.00e-07 1.20e-06 1.42e-06 erg/cm2
Error 1.71e-08 1.65e-08 2.67e-08 2.81e-07 5.74e-08 1.63e-07 erg/cm2
Peak flux Band 4.62e-01 6.30e-01 4.72e-01 2.25e-01 1.71e+00 1.79e+00 ph/cm2/s
Error 9.10e-02 4.73e-02 5.17e-02 1.32e-01 1.49e-01 1.95e-01 ph/cm2/s
=== Time-averaged spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.646 0.069 - - 7.51e-03 2.82e-04 69.036 57
CPL 0.915 0.315 74.5 14.2 1.73e-02 6.30e-03 50.366 56
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.404 0.134 - - 1.45e-02 1.17e-03 55.714 57
CPL 0.508 0.645 84.1 41.9 4.09e-02 3.45e-02 48.612 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: 11.008000 sec.
T50 in the 50-300 keV band: 5.248000 sec.
=== Table of the duration information ==
Value tstart tstop
T100 18.228 -0.652 17.576
T90 13.220 0.424 13.644
T50 5.868 3.116 8.984
Peak 1.000 4.312 5.312
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
276.1978 +37.6026 0.0042 18.0 -34.1 2.0054 46.3 TRIG_00176818
------------------------------------------
Foreground time interval of the image:
-0.652 13.733 (delta_t = 14.385 [sec])
Background time interval of the image:
-299.072 -0.652 (delta_t = 298.420 [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 -0.652 sec. to 17.576 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.64582 ( -6.847370E-02 6.871891E-02) )
Norm@50keV : 7.511824E-03 ( -2.826252E-04 2.821158E-04) )
------------------------------------------------------------
Chi-Squared = 69.03595 using 59 PHA bins.
Reduced chi-squared = 1.211157 for 57 degrees of freedom
Null hypothesis probability = 0.132
Photon flux (15-150 keV) in 18.23 sec: 0.979511 ( -0.038634 0.038749 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.27413e-06 ( -5.03987e-08 5.06685e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.652 sec. to 17.576 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.915179 ( -0.326793 0.302950 )
Epeak [keV] : 74.4674 ( -9.54633 18.7982 )
Norm@50keV : 1.729456E-02 ( -4.961866E-03 7.628424E-03) )
------------------------------------------------------------
Chi-Squared = 50.36561 using 59 PHA bins.
Reduced chi-squared = 0.8993859 for 56 degrees of freedom
Null hypothesis probability = 0.687
Photon flux (15-150 keV) in 18.23 sec: 0.935705 ( -0.042192 0.042244 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.20342e-06 ( -5.80862e-08 5.85019e-08 ) ergs/cm2
Band function
Time interval is from -0.652 sec. to 17.576 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.876532 ( -0.329238 0.838681 )
beta : -2.41822 ( -7.58178 0.508229 )
Epeak [keV] : 72.2664 ( -43.9644 19.7546 )
Norm@50keV : 1.820990E-02 ( -5.703785E-03 0.127079 )
------------------------------------------------------------
Chi-Squared = 50.13775 using 59 PHA bins.
Reduced chi-squared = 0.9115954 for 55 degrees of freedom
Null hypothesis probability = 0.661
Photon flux (15-150 keV) in 18.23 sec: 0.934540 ( -0.042567 0.041857 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.20177e-06 ( -5.68357e-08 5.78802e-08 ) ergs/cm2
Peak spectrum fit using the pre-slew DRM
Power-law model
Time interval is from 4.312 sec. to 5.312 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.40409 ( -0.134240 0.134707 )
Norm@50keV : 1.447233E-02 ( -1.172553E-03 1.170114E-03) )
------------------------------------------------------------
Chi-Squared = 55.71385 using 59 PHA bins.
Reduced chi-squared = 0.9774360 for 57 degrees of freedom
Null hypothesis probability = 0.523
Photon flux (15-150 keV) in 1.000 sec: 1.76411 ( -0.14368 0.14384 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.39703e-07 ( -1.2452e-08 1.2592e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 4.312 sec. to 5.312 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.507783 ( -0.695344 0.594884 )
Epeak [keV] : 84.0535 ( -17.9855 65.7798 )
Norm@50keV : 4.085133E-02 ( -1.999430E-02 4.895781E-02) )
------------------------------------------------------------
Chi-Squared = 48.61208 using 59 PHA bins.
Reduced chi-squared = 0.8680729 for 56 degrees of freedom
Null hypothesis probability = 0.748
Photon flux (15-150 keV) in 1.000 sec: 1.71088 ( -0.14869 0.14832 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.32068e-07 ( -1.3772e-08 1.3795e-08 ) ergs/cm2
Band function
Time interval is from 4.312 sec. to 5.312 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.507493 ( -0.595147 0.666948 )
beta : -9.15908 ( -0.840919 19.1590 )
Epeak [keV] : 84.0350 ( -18.9956 65.5971 )
Norm@50keV : 4.086256E-02 ( -2.001852E-02 4.898617E-02) )
------------------------------------------------------------
Chi-Squared = 48.61200 using 59 PHA bins.
Reduced chi-squared = 0.8838544 for 55 degrees of freedom
Null hypothesis probability = 0.716
Photon flux (15-150 keV) in 1.000 sec: 1.71068 ( -0.14849 0.14862 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.32037e-07 ( -1.3815e-08 1.3729e-08 ) ergs/cm2
Plot creation:
Mon Dec 31 09:06:08 EST 2007