batgrbproduct Analysis for Trigger=180977
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 11:53:41 EST 2007
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger180977/SDC
======================================================================
Trigger: 00180977 Segment: 000
BAT Trigger Time: 161240330.816 [s; MET]
Trigger Stop: 161240331.84 [s; MET]
UTC: 2006-02-10T04:58:49.809180 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 57.7298227424729 Dec: 27.025788071336 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 8.42
Image Trigger?: NO
Rate S/N Ratio: 27.5862284482674 [ if not an image trigger ]
Image S/N Ratio: 8.42
Flight Position: [ source = BAT ]
RA: 57.7298227424729 Dec: 27.025788071336 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 57.7288641318885 Dec: 27.0206039565173 [deg; J2000]
{ 03h 50m 54.9s , +27d 01' 14.2" }
+/- 1.02641962322374 [arcmin] (estimated 90% radius based on SNR)
+/- 0.283890145105799 [arcmin] (formal 1-sigma fit error)
SNR: 29.3048758077687
RA = 3h 50m 54.9s (57.728864 deg.)
Dec = 27d 1' 14" (27.020604 deg.)
Angular difference between Flight and Ground position is 0.315239 arcmin
Partial Coding Fraction: 0.4101562 [ including projection effects ]
Duration
T90: 255.004000008106 +/- 121.976522977757
Measured from: -149.636000007391
to: 105.368000000715 [s; relative to TRIGTIME]
T50: 43.6879999935627 +/- 8.34129296384666
Measured from: -43.3840000033379
to: 0.303999990224838 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: -0.0200000107288361
to: 0.979999989271164 [s; relative to TRIGTIME]
Total Fluence
Measured from: -227.300000011921
to: 205.815999984741 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 2.913514 4.237575 3.407556 1.063277
0.190651 0.193605 0.171066 0.149648 [error]
Peak 0.062702 0.116985 0.102077 0.055851
0.009510 0.010634 0.010319 0.008577 [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 1.06e-06 1.91e-06 2.66e-06 7.71e-06 7.65e-06 1.33e-05 erg/cm2
Error 1.07e-07 1.13e-07 1.65e-07 1.08e-06 4.09e-07 1.17e-06 erg/cm2
Peak flux Power-law 6.96e-01 8.56e-01 7.63e-01 1.18e+00 2.72e+00 3.49e+00 ph/cm2/s
Error 1.39e-01 1.04e-01 7.83e-02 2.61e-01 2.79e-01 3.39e-01 ph/cm2/s
Fluence Cutoff-PL 1.01e-06 1.94e-06 2.71e-06 6.09e-06 7.59e-06 1.21e-05 erg/cm2
Error 1.35e-07 1.26e-07 2.28e-07 2.05e-06 4.27e-07 2.42e-06 erg/cm2
Peak flux Cutoff-PL 6.95e-01 8.56e-01 7.64e-01 1.17e+00 2.72e+00 3.48e+00 ph/cm2/s
Error 1.39e-01 1.04e-01 7.84e-02 2.59e-01 2.78e-01 3.38e-01 ph/cm2/s
Fluence Band 1.00e-06 1.93e-06 2.71e-06 6.09e-06 7.58e-06 1.23e-05 erg/cm2
Error 1.34e-07 1.25e-07 1.95e-07 2.39e-06 4.30e-07 1.91e-06 erg/cm2
Peak flux Band 6.45e-01 8.85e-01 7.64e-01 1.13e+00 2.70e+00 3.41e+00 ph/cm2/s
Error 1.81e-01 1.14e-01 7.53e-02 2.89e-01 2.83e-01 3.88e-01 ph/cm2/s
=== Time-averaged spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.525 0.094 - - 1.87e-03 9.56e-05 64.780 57
CPL 1.285 0.333 164.2 4950.8 2.41e-03 9.02e-04 64.150 0
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.165 0.168 - - 2.33e-02 2.25e-03 53.535 57
CPL 1.107 0.372 862.9 0.0 2.48e-02 2.25e-03 53.650 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: 76.416000 sec.
T50 in the 50-300 keV band: 35.392000 sec.
=== Table of the duration information ==
Value tstart tstop
T100 433.116 -227.300 205.816
T90 255.004 -149.636 105.368
T50 43.688 -43.384 0.304
Peak 1.000 -0.020 0.980
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
57.7289 +27.0206 0.0065 44.1 178.6 3.0528 29.3 TRIG_00180977
------------------------------------------
Foreground time interval of the image:
-17.411 19.189 (delta_t = 36.600 [sec])
Background time interval of the image:
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 -227.300 sec. to 205.816 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.52524 ( -9.401011E-02 9.395897E-02) )
Norm@50keV : 1.868388E-03 ( -9.563915E-05 9.563658E-05) )
------------------------------------------------------------
Chi-Squared = 64.78001 using 59 PHA bins.
Reduced chi-squared = 1.136491 for 57 degrees of freedom
Null hypothesis probability = 0.224
Photon flux (15-150 keV) in 433.1 sec: 0.234867 ( -0.013366 0.013427 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.64573e-06 ( -4.0811e-07 4.08976e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -227.300 sec. to 205.816 sec.
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.28476 ( -0.344583 0.320763 )
Epeak [keV] : 164.246 ( -65.8428 9835.75 )
Norm@50keV : 2.408367E-03 ( -7.708974E-04 1.033504E-03) )
------------------------------------------------------------
Chi-Squared = 64.15029 using 59 PHA bins.
but latest trial 1.289758E-03 gives Chi-Squared = 100.799
Reduced chi-squared = 1.145541 for 56 degrees of freedom
Null hypothesis probability = 0.212
Photon flux (15-150 keV) in 433.1 sec: 0.232367 ( -0.014237 0.014221 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.58575e-06 ( -4.31974e-07 4.22446e-07 ) ergs/cm2
Band function
Time interval is from -227.300 sec. to 205.816 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.988881 ( -9.01112 1.02418 )
beta : -1.61689 ( -7.87594 0.680096 )
Epeak [keV] : 79.0928 ( -176.085 9823.81 )
Norm@50keV : 3.669316E-03 ( -5.598064E-04 4.386157E-03) )
------------------------------------------------------------
Chi-Squared = 64.27714 using 59 PHA bins.
Reduced chi-squared = 1.168675 for 55 degrees of freedom
Null hypothesis probability = 0.184
Photon flux (15-150 keV) in 433.1 sec: 0.232341 ( -0.014227 0.014286 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.57851e-06 ( -4.31194e-07 4.29245e-07 ) ergs/cm2
Peak spectrum fit using the pre-slew DRM
Power-law model
Time interval is from -0.020 sec. to 0.980 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.16528 ( -0.170419 0.165913 )
Norm@50keV : 2.330068E-02 ( -2.249464E-03 2.240812E-03) )
------------------------------------------------------------
Chi-Squared = 53.53515 using 59 PHA bins.
Reduced chi-squared = 0.9392132 for 57 degrees of freedom
Null hypothesis probability = 0.606
Photon flux (15-150 keV) in 1.000 sec: 2.72240 ( -0.27793 0.2791 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.38768e-07 ( -2.3811e-08 2.3891e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.020 sec. to 0.980 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.10730 ( -0.520425 0.223515 )
Epeak [keV] : 862.868 ( )
Norm@50keV : 2.480368E-02 ( -2.256270E-03 2.248472E-03) )
------------------------------------------------------------
Chi-Squared = 53.64987 using 59 PHA bins.
Reduced chi-squared = 0.9580334 for 56 degrees of freedom
Null hypothesis probability = 0.564
Photon flux (15-150 keV) in 1.000 sec: 2.72179 ( -0.27786 0.27901 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.38874e-07 ( -2.3829e-08 2.3904e-08 ) ergs/cm2
Band function
Time interval is from -0.020 sec. to 0.980 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.524487 ( -11.8398 3.16021 )
beta : -1.23235 ( -0.198894 0.191750 )
Epeak [keV] : 85.7667 ( -33.7122 619.961 )
Norm@50keV : 5.599031E-02 ( -147.895 333.641 )
------------------------------------------------------------
Chi-Squared = 52.98808 using 59 PHA bins.
Reduced chi-squared = 0.9634196 for 55 degrees of freedom
Null hypothesis probability = 0.552
Photon flux (15-150 keV) in 1.000 sec: 2.69748 ( -0.28883 0.27707 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.38613e-07 ( -2.3723e-08 2.3955e-08 ) ergs/cm2
Plot creation:
Mon Dec 31 12:07:10 EST 2007