batgrbproduct Analysis for Trigger=321481
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): Sat Aug 23 17:51:12 EDT 2008
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger321481/GCN5_download_cron
======================================================================
Trigger: 00321481 Segment: 000
BAT Trigger Time: 241159671.64 [s; MET]
Trigger Stop: 241159671.656 [s; MET]
UTC: 2008-08-23T04:47:48.599800 [includes UTCF correction]
Where From?: (*SHORT BURST*) TDRSS scaled map message
BAT
RA: 75.2703524009689 Dec: 45.278018692367 [deg; J2000]
Catalogged Source?: YES
Point Source?: YES
GRB Indicated?: NO [ by BAT flight software ]
Image S/N Ratio: 24.4
Image Trigger?: NO
Rate S/N Ratio: 255.998046867549 [ if not an image trigger ]
Image S/N Ratio: 24.4
Flight Position: [ source = BAT ]
RA: 75.2703524009689 Dec: 45.278018692367 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 75.2764024988385 Dec: 45.2725594512674 [deg; J2000]
{ 05h 01m 06.3s , +45d 16' 21.2" }
+/- 0.431402087600575 [arcmin] (estimated 90% radius based on SNR)
+/- 0.098125458672936 [arcmin] (formal 1-sigma fit error)
SNR: 101.091624749558
Angular difference between Flight and Ground position is 0.415386 arcmin
Partial Coding Fraction: 1.015625 [ including projection effects ]
Duration
T90: 0.708000004291534 +/- 0.0126491268505387
Measured from: -0.0119999051094055
to: 0.696000099182129 [s; relative to TRIGTIME]
T50: 0.0879999995231628 +/- 0.0160000026226044
Measured from: 0.00400009751319885
to: 0.0920000970363617 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: -0.0759999752044678
to: 0.924000024795532 [s; relative to TRIGTIME]
Total Fluence
Measured from: -0.0599999725818634
to: 0.904000014066696 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 1.605612 1.450156 0.380357 0.004141
0.016744 0.015991 0.009658 0.006492 [error]
Peak 1.605822 1.450241 0.380596 0.004371
0.016750 0.015995 0.009666 0.006504 [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 6.36e-07 5.26e-07 2.95e-07 2.45e-07 1.57e-06 1.70e-06 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 Power-law 2.18e+01 1.01e+01 2.84e+00 9.98e-01 3.53e+01 3.58e+01 ph/cm2/s
Error 0.00e+00 0.00e+00 0.00e+00 0.00e+00 0.00e+00 0.00e+00 ph/cm2/s
Fluence Cutoff-PL 4.52e-07 5.99e-07 2.82e-07 3.59e-08 1.37e-06 1.35e-06 erg/cm2
Error 1.49e-08 1.22e-08 8.06e-09 3.95e-08 0.00e+00 0.00e+00 erg/cm2
Peak flux Cutoff-PL 1.54e+01 1.13e+01 2.83e+00 1.95e-01 2.98e+01 2.98e+01 ph/cm2/s
Error 9.99e-01 2.81e-01 1.11e-01 4.09e-02 1.11e+00 1.11e+00 ph/cm2/s
Fluence Band 4.62e-07 5.99e-07 2.77e-07 6.05e-08 1.37e-06 1.56e-06 erg/cm2
Error 1.32e-08 8.93e-09 1.90e-08 3.26e-08 0.00e+00 0.00e+00 erg/cm2
Peak flux Band 1.56e+01 1.13e+01 2.83e+00 2.93e-01 2.97e+01 3.11e+01 ph/cm2/s
Error 4.72e-01 2.76e-01 8.18e-02 5.69e-02 1.13e+00 0.00e+00 ph/cm2/s
=== Time-averaged spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 2.833 0.000 - - 1.45e-01 0.00e+00 270.798 57
CPL 0.837 0.272 25.6 2.6 1.71e+00 5.87e-01 41.093 56
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 2.832 0.000 - - 1.45e-01 0.00e+00 270.377 57
CPL 0.841 0.271 25.6 2.6 1.70e+00 5.81e-01 41.618 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: 0.768000 sec.
T50 in the 50-300 keV band: 0.384000 sec.
=== Table of the duration information ==
Value tstart tstop
T100 0.964 -0.060 0.904
T90 0.708 -0.012 0.696
T50 0.088 0.004 0.092
Peak 1.000 -0.076 0.924
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
75.2764 +45.2726 0.0019 0.0 60.3 3.4237 101.1 TRIG_00321481
------------------------------------------
Foreground time interval of the image:
-0.060 0.904 (delta_t = 0.964 [sec])
Background time interval of the image:
-119.640 -56.621 (delta_t = 63.019 [sec])
-55.640 -0.060 (delta_t = 55.580 [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 -0.060 sec. to 0.904 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.83302 ( )
Norm@50keV : 0.145304 ( )
------------------------------------------------------------
Chi-Squared = 270.7980 using 59 PHA bins.
Reduced chi-squared = 4.750842 for 57 degrees of freedom
Null hypothesis probability = 1.430E-29
Photon flux (15-150 keV) in 0.9640 sec: 35.4902 ( ) ph/cm2/s
Energy fluence (15-150 keV) : 1.56632e-06 ( 0 0 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.060 sec. to 0.904 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.836663 ( -0.278616 0.264665 )
Epeak [keV] : 25.6338 ( -2.90549 2.37116 )
Norm@50keV : 1.71184 ( -0.474395 0.700057 )
------------------------------------------------------------
Chi-Squared = 41.09258 using 59 PHA bins.
Reduced chi-squared = 0.7337961 for 56 degrees of freedom
Null hypothesis probability = 0.932
Photon flux (15-150 keV) in 0.9640 sec: 29.8710 ( -1.1078 1.1216 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.37373e-06 ( -3.92531e-08 3.9792e-08 ) ergs/cm2
Band function
Time interval is from -0.060 sec. to 0.904 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.30681 ( -0.309299 0.269364 )
beta : -9.16770 ( -5.45772 0.525171 )
Epeak [keV] : 20.1143 ( -3.49032 1.99981 )
Norm@50keV : 0.959433 ( -0.801327 0.912237 )
------------------------------------------------------------
Chi-Squared = 50.14321 using 59 PHA bins.
Reduced chi-squared = 0.9116948 for 55 degrees of freedom
Null hypothesis probability = 0.660
Photon flux (15-150 keV) in 0.9640 sec: 29.7662 ( -1.1181 1.1486 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.37079e-06 ( -3.52679e-08 2.98917e-08 ) ergs/cm2
Peak spectrum fit using the pre-slew DRM
Power-law model
Time interval is from -0.060 sec. to 0.908 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.83219 ( )
Norm@50keV : 0.144789 ( )
------------------------------------------------------------
Chi-Squared = 270.3770 using 59 PHA bins.
Reduced chi-squared = 4.743455 for 57 degrees of freedom
Null hypothesis probability = 1.692E-29
Photon flux (15-150 keV) in 0.9680 sec: 35.3437 ( ) ph/cm2/s
Energy fluence (15-150 keV) : 1.56673e-06 ( 0 0 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.060 sec. to 0.908 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.840740 ( -0.278515 0.264451 )
Epeak [keV] : 25.6083 ( -2.91500 2.37868 )
Norm@50keV : 1.69536 ( -0.469529 0.693008 )
------------------------------------------------------------
Chi-Squared = 41.61842 using 59 PHA bins.
Reduced chi-squared = 0.7431861 for 56 degrees of freedom
Null hypothesis probability = 0.924
Photon flux (15-150 keV) in 0.9680 sec: 29.7588 ( -1.1027 1.118 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.37441e-06 ( -3.92902e-08 3.97964e-08 ) ergs/cm2
Band function
Time interval is from -0.060 sec. to 0.908 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.30672 ( -0.191045 0.302912 )
beta : -9.20854 ( )
Epeak [keV] : 20.1293 ( )
Norm@50keV : 0.954923 ( )
------------------------------------------------------------
Chi-Squared = 50.51973 using 59 PHA bins.
Reduced chi-squared = 0.9185405 for 55 degrees of freedom
Null hypothesis probability = 0.646
Photon flux (15-150 keV) in 0.9680 sec: 29.6634 ( -1.1257 1.1327 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.37522e-06 ( -3.30514e-08 3.39845e-08 ) ergs/cm2
Plot creation:
Sat Aug 23 18:05:03 EDT 2008