batgrbproduct Analysis for Trigger=287260
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): Fri Dec 14 07:55:05 EST 2007
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger287260/SDC
======================================================================
Trigger: 00287260 Segment: 000
BAT Trigger Time: 208290482.688 [s; MET]
Trigger Stop: 208290483.712 [s; MET]
UTC: 2007-08-08T18:28:00.545880 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 6.7657965873297 Dec: 1.16645825164436 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 13.2
Image Trigger?: NO
Rate S/N Ratio: 26.0959767013998 [ if not an image trigger ]
Image S/N Ratio: 13.2
Flight Position: [ source = BAT ]
RA: 6.7657965873297 Dec: 1.16645825164436 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 6.75455983772343 Dec: 1.17967616524712 [deg; J2000]
{ 00h 27m 01.1s , +01d 10' 46.8" }
+/- 1.21908865351562 [arcmin] (estimated 90% radius based on SNR)
+/- 0.452049698694845 [arcmin] (formal 1-sigma fit error)
SNR: 22.9198000224562
RA = 0h 27m 1.1s (6.754560 deg.)
Dec = 1d 10' 47" (1.179676 deg.)
Angular difference between Flight and Ground position is 1.040831 arcmin
Partial Coding Fraction: 0.4726562 [ including projection effects ]
Duration
T90: 58.7520000040531 +/- 12.1164694385092
Measured from: -0.00799998641014099
to: 58.744000017643 [s; relative to TRIGTIME]
T50: 20.7360000312328 +/- 5.85905928317912
Measured from: 1.91200000047684
to: 22.6480000317097 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 0.740000009536743
to: 1.74000000953674 [s; relative to TRIGTIME]
Total Fluence
Measured from: -0.711999982595444
to: 71.7360000014305 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.504489 0.750115 0.538813 0.192944
0.052596 0.053441 0.047949 0.041608 [error]
Peak 0.038724 0.084944 0.079300 0.018941
0.007681 0.008327 0.008178 0.006336 [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 1.77e-07 3.18e-07 4.41e-07 1.27e-06 1.27e-06 2.20e-06 erg/cm2
Error 2.65e-08 2.84e-08 4.66e-08 2.97e-07 1.13e-07 3.28e-07 erg/cm2
Peak flux Power-law 5.06e-01 6.06e-01 5.25e-01 7.78e-01 1.91e+00 2.42e+00 ph/cm2/s
Error 1.06e-01 7.94e-02 6.39e-02 1.95e-01 2.19e-01 2.73e-01 ph/cm2/s
Fluence Cutoff-PL 1.71e-07 3.24e-07 4.49e-07 9.85e-07 1.26e-06 1.88e-06 erg/cm2
Error 3.21e-08 3.28e-08 5.26e-08 5.46e-07 8.78e-08 5.62e-07 erg/cm2
Peak flux Cutoff-PL 4.04e-01 6.42e-01 5.89e-01 3.74e-01 1.86e+00 2.01e+00 ph/cm2/s
Error 1.30e-01 9.19e-02 8.50e-02 2.41e-01 2.24e-01 3.24e-01 ph/cm2/s
Fluence Band 1.68e-07 3.23e-07 4.48e-07 9.81e-07 1.26e-06 1.94e-06 erg/cm2
Error 3.18e-08 3.26e-08 5.26e-08 5.46e-07 1.19e-07 5.31e-07 erg/cm2
Peak flux Band 4.04e-01 6.42e-01 5.89e-01 3.75e-01 1.86e+00 2.01e+00 ph/cm2/s
Error 1.30e-01 9.19e-02 8.50e-02 2.40e-01 2.24e-01 3.25e-01 ph/cm2/s
=== Time-averaged spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.530 0.149 - - 1.85e-03 1.53e-04 61.821 57
CPL 1.286 0.479 156.1 4959.9 2.43e-03 1.33e-03 61.526 0
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.207 0.181 - - 1.63e-02 1.79e-03 53.952 57
CPL 0.291 0.843 105.9 118.6 4.24e-02 4.32e-02 49.578 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: 31.040000 sec.
T50 in the 50-300 keV band: 13.056000 sec.
=== Table of the duration information ==
Value tstart tstop
T100 72.448 -0.712 71.736
T90 58.752 -0.008 58.744
T50 20.736 1.912 22.648
Peak 1.000 0.740 1.740
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
6.7546 +1.1797 0.0084 39.4 168.4 1.5778 22.9 TRIG_00287260
------------------------------------------
Foreground time interval of the image:
-0.712 21.917 (delta_t = 22.629 [sec])
Background time interval of the image:
-239.688 -0.712 (delta_t = 238.976 [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 -0.712 sec. to 71.736 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.53001 ( -0.148626 0.149558 )
Norm@50keV : 1.854504E-03 ( -1.533927E-04 1.527801E-04) )
------------------------------------------------------------
Chi-Squared = 61.82070 using 59 PHA bins.
Reduced chi-squared = 1.084574 for 57 degrees of freedom
Null hypothesis probability = 0.308
Photon flux (15-150 keV) in 72.45 sec: 0.233433 ( -0.020152 0.020247 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.26866e-06 ( -1.12442e-07 1.12841e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.712 sec. to 71.736 sec.
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.28576 ( -0.574269 0.383760 )
Epeak [keV] : 156.080 ( -75.9830 9843.92 )
Norm@50keV : 2.429168E-03 ( -6.072919E-04 2.059053E-03) )
------------------------------------------------------------
Chi-Squared = 61.52605 using 59 PHA bins.
but latest trial 1.560560E-03 gives Chi-Squared = 10.4738
Reduced chi-squared = 1.098679 for 56 degrees of freedom
Null hypothesis probability = 0.285
Photon flux (15-150 keV) in 72.45 sec: 0.231294 ( -0.020636 0.020799 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.25718e-06 ( -6.01915e-08 1.15406e-07 ) ergs/cm2
Band function
Time interval is from -0.712 sec. to 71.736 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.07655 ( -6.72348 5.85038 )
beta : -1.62657 ( -0.149351 0.148520 )
Epeak [keV] : 85.0507 ( -84.9507 9914.95 )
Norm@50keV : 3.294902E-03 ( -2.084525E-02 2.076602E-02) )
------------------------------------------------------------
Chi-Squared = 62.01270 using 59 PHA bins.
Reduced chi-squared = 1.127504 for 55 degrees of freedom
Null hypothesis probability = 0.240
Photon flux (15-150 keV) in 72.45 sec: 0.231270 ( -0.021151 0.02112 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.25587e-06 ( -1.19666e-07 1.17999e-07 ) ergs/cm2
Peak spectrum fit using the pre-slew DRM
Power-law model
Time interval is from 0.760 sec. to 1.720 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.20661 ( -0.182456 0.179972 )
Norm@50keV : 1.626762E-02 ( -1.787217E-03 1.786312E-03) )
------------------------------------------------------------
Chi-Squared = 53.95243 using 59 PHA bins.
Reduced chi-squared = 0.9465338 for 57 degrees of freedom
Null hypothesis probability = 0.590
Photon flux (15-150 keV) in 0.9600 sec: 1.91129 ( -0.21877 0.21944 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.58141e-07 ( -1.8527e-08 1.86346e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.760 sec. to 1.720 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.291244 ( -0.925576 0.760379 )
Epeak [keV] : 105.872 ( -28.3300 208.826 )
Norm@50keV : 4.239981E-02 ( -2.286702E-02 6.348130E-02) )
------------------------------------------------------------
Chi-Squared = 49.57780 using 59 PHA bins.
Reduced chi-squared = 0.8853179 for 56 degrees of freedom
Null hypothesis probability = 0.715
Photon flux (15-150 keV) in 0.9600 sec: 1.85895 ( -0.22319 0.22397 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.53957e-07 ( -1.94477e-08 1.95946e-08 ) ergs/cm2
Band function
Time interval is from 0.760 sec. to 1.720 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.292074 ( -0.759581 0.494228 )
beta : -7.87585 ( -2.12415 6.65295 )
Epeak [keV] : 105.905 ( -21.9031 208.572 )
Norm@50keV : 4.236411E-02 ( -2.283166E-02 6.374553E-02) )
------------------------------------------------------------
Chi-Squared = 49.57787 using 59 PHA bins.
Reduced chi-squared = 0.9014159 for 55 degrees of freedom
Null hypothesis probability = 0.681
Photon flux (15-150 keV) in 0.9600 sec: 1.85913 ( -0.22337 0.2238 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.5399e-07 ( -1.95533e-08 1.94506e-08 ) ergs/cm2
Plot creation:
Fri Dec 14 08:10:49 EST 2007