batgrbproduct Analysis for Trigger=278693
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): Thu Dec 13 20:09:37 EST 2007
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger278693/GCN5_download_cron
======================================================================
Trigger: 00278693 Segment: 000
BAT Trigger Time: 200122560 [s; MET]
Trigger Stop: 200122624 [s; MET]
UTC: 2007-05-06T05:35:58.063600 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 347.217597658185 Dec: 10.7283397482321 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 8.48
Image Trigger?: YES
Rate S/N Ratio: 0 [ if not an image trigger ]
Image S/N Ratio: 8.48
Flight Position: [ source = BAT ]
RA: 347.217597658185 Dec: 10.7283397482321 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 347.209186486155 Dec: 10.7132068124771 [deg; J2000]
{ 23h 08m 50.2s , +10d 42' 47.5" }
+/- 1.94973610311329 [arcmin] (estimated 90% radius based on SNR)
+/- 0.825189602697911 [arcmin] (formal 1-sigma fit error)
SNR: 11.7183695340514
RA = 23h 8m 50.2s (347.209186 deg.)
Dec = 10d 42' 48" (10.713207 deg.)
Angular difference between Flight and Ground position is 1.034553 arcmin
Partial Coding Fraction: 0.96875 [ including projection effects ]
Duration
T90: 4.32800000905991 +/- 0.485254568684771
Measured from: 4.27599999308586
to: 8.60400000214577 [s; relative to TRIGTIME]
T50: 1.95600000023842 +/- 0.633567695499284
Measured from: 5.30799999833107
to: 7.26399999856949 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 6.15599998831749
to: 7.15599998831749 [s; relative to TRIGTIME]
Total Fluence
Measured from: 4.0959999859333
to: 9.02399998903275 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.113144 0.151125 0.085871 0.006504
0.011011 0.011402 0.010319 0.009841 [error]
Peak 0.039354 0.054248 0.026396 -0.000544
0.005190 0.005318 0.004723 0.004441 [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 3.58e-08 5.75e-08 6.95e-08 1.65e-07 2.10e-07 3.30e-07 erg/cm2
Error 4.94e-09 5.22e-09 9.93e-09 4.79e-08 2.32e-08 5.76e-08 erg/cm2
Peak flux Power-law 3.82e-01 3.38e-01 2.05e-01 1.89e-01 1.01e+00 1.11e+00 ph/cm2/s
Error 6.85e-02 4.20e-02 3.74e-02 6.51e-02 1.25e-01 1.43e-01 ph/cm2/s
Fluence Cutoff-PL 3.32e-08 6.33e-08 6.81e-08 4.66e-08 1.93e-07 2.11e-07 erg/cm2
Error 5.54e-09 7.37e-09 1.18e-08 5.93e-08 2.70e-08 6.55e-08 erg/cm2
Peak flux Cutoff-PL 3.30e-01 4.14e-01 1.94e-01 2.59e-02 9.61e-01 9.64e-01 ph/cm2/s
Error 7.76e-02 6.26e-02 5.22e-02 3.96e-02 1.26e-01 1.29e-01 ph/cm2/s
Fluence Band 2.76e-07 0.00e+00 0.00e+00 0.00e+00 0.00e+00 0.00e+00 erg/cm2
Error 0.00e+00 0.00e+00 0.00e+00 0.00e+00 0.00e+00 0.00e+00 erg/cm2
Peak flux Band 3.32e-01 4.13e-01 1.95e-01 2.68e-02 9.62e-01 9.66e-01 ph/cm2/s
Error 5.96e-02 5.06e-02 2.35e-02 5.77e-02 1.19e-01 1.21e-01 ph/cm2/s
=== Time-averaged spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.725 0.165 - - 4.61e-03 4.82e-04 55.755 57
CPL 0.924 0.770 57.8 50.6 1.31e-02 1.68e-02 51.804 0
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.719 0.207 - - 7.52e-03 1.07e-03 55.899 57
CPL -0.045 1.227 47.3 12.0 8.12e-02 2.75e-01 46.263 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: 8.640000 sec.
T50 in the 50-300 keV band: 3.264000 sec.
=== Table of the duration information ==
Value tstart tstop
T100 4.928 4.096 9.024
T90 4.328 4.276 8.604
T50 1.956 5.308 7.264
Peak 1.000 6.156 7.156
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
347.2092 +10.7132 0.0164 15.3 22.0 0.3228 11.7 TRIG_00278693
------------------------------------------
Foreground time interval of the image:
4.096 9.024 (delta_t = 4.928 [sec])
Background time interval of the image:
-2.999 4.096 (delta_t = 7.095 [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 4.096 sec. to 9.024 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.72468 ( -0.163175 0.167757 )
Norm@50keV : 4.613278E-03 ( -4.858011E-04 4.786635E-04) )
------------------------------------------------------------
Chi-Squared = 55.75463 using 59 PHA bins.
Reduced chi-squared = 0.9781515 for 57 degrees of freedom
Null hypothesis probability = 0.522
Photon flux (15-150 keV) in 4.928 sec: 0.618076 ( -0.056344 0.056361 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.1013e-07 ( -2.29921e-08 2.33888e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 4.096 sec. to 9.024 sec.
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.923532 ( -0.842688 0.696347 )
Epeak [keV] : 57.8278 ( -12.9723 88.2389 )
Norm@50keV : 1.309995E-02 ( -7.269081E-03 2.642961E-02) )
------------------------------------------------------------
Chi-Squared = 51.80378 using 59 PHA bins.
but latest trial 5.472643E-03 gives Chi-Squared = 12.4676
Reduced chi-squared = 0.9250675 for 56 degrees of freedom
Null hypothesis probability = 0.634
Photon flux (15-150 keV) in 4.928 sec: 0.598879 ( -0.058636 0.058628 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.92575e-07 ( -2.64121e-08 2.76293e-08 ) ergs/cm2
Band function
Time interval is from 4.096 sec. to 9.024 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.244192 ( -1.36916 2.07866 )
beta : -2.00497 ( -0.340079 0.309355 )
Epeak [keV] : 40.0976 ( -7.91207 22.4762 )
Norm@50keV : 4.112087E-02 ( -1.73677 129.019 )
------------------------------------------------------------
Chi-Squared = 50.56925 using 59 PHA bins.
Reduced chi-squared = 0.9194409 for 55 degrees of freedom
Null hypothesis probability = 0.644
Photon flux (15-150 keV) in 4.928 sec: 0.608455 ( -0.062142 0.055573 ) ph/cm2/s
Energy fluence (15-150 keV) : 0 ( 0 0 ) ergs/cm2
Peak spectrum fit using the pre-slew DRM
Power-law model
Time interval is from 6.156 sec. to 7.156 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.71918 ( -0.203369 0.210207 )
Norm@50keV : 7.521256E-03 ( -1.075432E-03 1.057391E-03) )
------------------------------------------------------------
Chi-Squared = 55.89936 using 59 PHA bins.
Reduced chi-squared = 0.9806906 for 57 degrees of freedom
Null hypothesis probability = 0.516
Photon flux (15-150 keV) in 1.000 sec: 1.00567 ( -0.124859 0.1249 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.95343e-08 ( -1.02408e-08 1.04904e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 6.156 sec. to 7.156 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -4.503339E-02 ( -1.40298 1.05059 )
Epeak [keV] : 47.3216 ( -8.09228 15.8147 )
Norm@50keV : 8.116731E-02 ( -6.115714E-02 0.488021 )
------------------------------------------------------------
Chi-Squared = 46.26309 using 59 PHA bins.
Reduced chi-squared = 0.8261266 for 56 degrees of freedom
Null hypothesis probability = 0.820
Photon flux (15-150 keV) in 1.000 sec: 0.961115 ( -0.125237 0.126055 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.88494e-08 ( -1.0098e-08 1.1383e-08 ) ergs/cm2
Band function
Time interval is from 6.156 sec. to 7.156 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : 9.177110E-02 ( -1.01219 1.13242 )
beta : -9.11135 ( -0.888653 7.23536 )
Epeak [keV] : 47.0559 ( -10.3221 9.56414 )
Norm@50keV : 8.655546E-02 ( -124.696 25.1487 )
------------------------------------------------------------
Chi-Squared = 46.26656 using 59 PHA bins.
Reduced chi-squared = 0.8412102 for 55 degrees of freedom
Null hypothesis probability = 0.793
Photon flux (15-150 keV) in 1.000 sec: 0.961588 ( -0.116307 0.121372 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.3562e-08 ( -1.04542e-08 9.6852e-09 ) ergs/cm2
Plot creation:
Thu Dec 13 20:27:39 EST 2007