batgrbproduct Analysis for Trigger=280706
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 00:18:04 EST 2007
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger280706/GCN5_download_cron
======================================================================
Trigger: 00280706 Segment: 000
BAT Trigger Time: 202135710.336 [s; MET]
Trigger Stop: 202135722.496 [s; MET]
UTC: 2007-05-29T12:48:28.349220 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 283.750487750051 Dec: 20.6391633973926 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 6.76
Image Trigger?: NO
Rate S/N Ratio: 12.1243556529821 [ if not an image trigger ]
Image S/N Ratio: 6.76
Flight Position: [ source = BAT ]
RA: 283.750487750051 Dec: 20.6391633973926 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 283.717770281458 Dec: 20.6511734073084 [deg; J2000]
{ 18h 54m 52.3s , +20d 39' 04.2" }
+/- 1.79667723081054 [arcmin] (estimated 90% radius based on SNR)
+/- 0.844764743630404 [arcmin] (formal 1-sigma fit error)
SNR: 13.1701195448271
RA = 18h 54m 52.3s (283.717770 deg.)
Dec = 20d 39' 4" (20.651173 deg.)
Angular difference between Flight and Ground position is 1.973266 arcmin
Partial Coding Fraction: 0.1699219 [ including projection effects ]
Duration
T90: 89.4840000271797 +/- 19.9827798950972
Measured from: 2.29199999570847
to: 91.7760000228882 [s; relative to TRIGTIME]
T50: 55.8680000007153 +/- 8.49368732032293
Measured from: 12.7960000038147
to: 68.66400000453 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 2.02400001883507
to: 3.02400001883507 [s; relative to TRIGTIME]
Total Fluence
Measured from: -1.24799999594688
to: 120.884000003338 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.875772 1.308735 1.187886 0.395743
0.111638 0.113693 0.101069 0.084914 [error]
Peak 0.025654 0.066584 0.059403 0.026683
0.012874 0.014163 0.013169 0.010562 [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 3.03e-07 6.01e-07 9.27e-07 3.13e-06 2.59e-06 4.94e-06 erg/cm2
Error 5.23e-08 6.19e-08 9.80e-08 7.43e-07 2.45e-07 7.98e-07 erg/cm2
Peak flux Power-law 3.94e-01 4.59e-01 3.85e-01 5.47e-01 1.43e+00 1.78e+00 ph/cm2/s
Error 1.73e-01 1.29e-01 1.02e-01 2.94e-01 3.57e-01 4.32e-01 ph/cm2/s
Fluence Cutoff-PL 2.93e-07 6.08e-07 9.40e-07 2.67e-06 2.58e-06 4.19e-06 erg/cm2
Error 6.05e-08 5.14e-08 1.12e-07 1.32e-06 2.86e-07 1.60e-06 erg/cm2
Peak flux Cutoff-PL 2.84e-01 4.92e-01 4.49e-01 2.23e-01 1.38e+00 1.45e+00 ph/cm2/s
Error 2.05e-01 1.55e-01 1.35e-01 3.59e-01 3.65e-01 3.50e-01 ph/cm2/s
Fluence Band 2.87e-07 6.18e-07 9.24e-07 2.97e-06 2.58e-06 4.89e-06 erg/cm2
Error 8.20e-08 8.07e-08 9.67e-08 1.20e-06 2.64e-07 9.50e-07 erg/cm2
Peak flux Band 2.84e-01 4.91e-01 4.49e-01 2.24e-01 1.38e+00 1.45e+00 ph/cm2/s
Error 2.05e-01 1.56e-01 1.35e-01 3.19e-01 3.65e-01 4.81e-01 ph/cm2/s
=== Time-averaged spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.375 0.158 - - 2.19e-03 1.94e-04 50.747 57
CPL 1.182 0.450 229.6 4951.5 2.69e-03 0.00e+00 50.641 56
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.252 0.389 - - 1.21e-02 2.88e-03 49.210 57
CPL -0.013 1.913 91.0 4969.5 4.47e-02 2.02e-01 47.311 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: 75.328000 sec.
T50 in the 50-300 keV band: 47.168000 sec.
=== Table of the duration information ==
Value tstart tstop
T100 122.132 -1.248 120.884
T90 89.484 2.292 91.776
T50 55.868 12.796 68.664
Peak 1.000 2.024 3.024
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
283.7178 +20.6512 0.0146 41.1 45.0 2.5978 13.2 TRIG_00280706
------------------------------------------
Foreground time interval of the image:
-1.248 53.365 (delta_t = 54.613 [sec])
Background time interval of the image:
-239.336 -224.496 (delta_t = 14.840 [sec])
-223.336 -223.046 (delta_t = 0.290 [sec])
-222.336 -1.248 (delta_t = 221.088 [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 -1.248 sec. to 120.884 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.37514 ( -0.158847 0.156573 )
Norm@50keV : 2.185766E-03 ( -1.943952E-04 1.943866E-04) )
------------------------------------------------------------
Chi-Squared = 50.74672 using 59 PHA bins.
Reduced chi-squared = 0.8902933 for 57 degrees of freedom
Null hypothesis probability = 0.707
Photon flux (15-150 keV) in 122.1 sec: 0.264719 ( -0.025276 0.025365 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.59234e-06 ( -2.44969e-07 2.45616e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -1.248 sec. to 120.884 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.18189 ( -0.555527 0.344373 )
Epeak [keV] : 229.559 ( -132.533 9770.44 )
Norm@50keV : 2.694515E-03 ( )
------------------------------------------------------------
Chi-Squared = 50.64058 using 59 PHA bins.
Reduced chi-squared = 0.9042961 for 56 degrees of freedom
Null hypothesis probability = 0.677
Photon flux (15-150 keV) in 122.1 sec: 0.263425 ( -0.025711 0.025883 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.58127e-06 ( -3.30732e-07 2.41697e-07 ) ergs/cm2
Band function
Time interval is from -1.248 sec. to 120.884 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.914725 ( -11.3224 1.28000 )
beta : -1.41242 ( -0.204006 0.211401 )
Epeak [keV] : 76.9221 ( -25.3010 433.404 )
Norm@50keV : 4.340556E-03 ( -18.1168 69.9513 )
------------------------------------------------------------
Chi-Squared = 50.24399 using 59 PHA bins.
Reduced chi-squared = 0.9135271 for 55 degrees of freedom
Null hypothesis probability = 0.657
Photon flux (15-150 keV) in 122.1 sec: 0.262533 ( -0.02461 0.026108 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.57624e-06 ( -2.54029e-07 2.74261e-07 ) ergs/cm2
Peak spectrum fit using the pre-slew DRM
Power-law model
Time interval is from 2.024 sec. to 3.024 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.25197 ( -0.393673 0.384045 )
Norm@50keV : 1.212235E-02 ( -2.881238E-03 2.878637E-03) )
------------------------------------------------------------
Chi-Squared = 49.21000 using 59 PHA bins.
Reduced chi-squared = 0.8633333 for 57 degrees of freedom
Null hypothesis probability = 0.759
Photon flux (15-150 keV) in 1.000 sec: 1.43422 ( -0.35526 0.35804 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.2125e-07 ( -3.04262e-08 3.0733e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 2.024 sec. to 3.024 sec.
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.262228E-02 ( -2.35596 1.46939 )
Epeak [keV] : 91.0186 ( -30.0768 9908.98 )
Norm@50keV : 4.468483E-02 ( -3.409874E-02 0.370325 )
------------------------------------------------------------
Chi-Squared = 47.31051 using 59 PHA bins.
but latest trial 52.6399 gives Chi-Squared = 5.32298
Reduced chi-squared = 0.8448306 for 56 degrees of freedom
Null hypothesis probability = 0.789
Photon flux (15-150 keV) in 1.000 sec: 1.37513 ( -0.36385 0.36653 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.17522e-07 ( -3.17054e-08 3.1729e-08 ) ergs/cm2
Band function
Time interval is from 2.024 sec. to 3.024 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : 1.449688E-02 ( -1.51978 1.57765 )
beta : -9.25415 ( -0.745850 8.21191 )
Epeak [keV] : 90.9659 ( -29.9357 9909.03 )
Norm@50keV : 4.476022E-02 ( -3.063653E-02 0.378096 )
------------------------------------------------------------
Chi-Squared = 47.31059 using 59 PHA bins.
Reduced chi-squared = 0.8601926 for 55 degrees of freedom
Null hypothesis probability = 0.760
Photon flux (15-150 keV) in 1.000 sec: 1.37519 ( -0.36382 0.36651 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.17257e-07 ( -3.14064e-08 3.1909e-08 ) ergs/cm2
Plot creation:
Fri Dec 14 00:38:44 EST 2007