batgrbproduct Analysis for Trigger=281993
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 01:06:10 EST 2007
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger281993/GCN5_download_cron
======================================================================
Trigger: 00281993 Segment: 000
BAT Trigger Time: 203201548.16 [s; MET]
Trigger Stop: 203201550.208 [s; MET]
UTC: 2007-06-10T20:52:26.146640 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 298.795395293668 Dec: 26.2137864105949 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 7.16
Image Trigger?: NO
Rate S/N Ratio: 10.770329614269 [ if not an image trigger ]
Image S/N Ratio: 7.16
Flight Position: [ source = BAT ]
RA: 298.795395293668 Dec: 26.2137864105949 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 298.804200034744 Dec: 26.2597554154888 [deg; J2000]
{ 19h 55m 13.0s , +26d 15' 35.1" }
+/- 1.87097185217072 [arcmin] (estimated 90% radius based on SNR)
+/- 0.731931251943604 [arcmin] (formal 1-sigma fit error)
SNR: 12.4294203184018
RA = 19h 55m 13.0s (298.804200 deg.)
Dec = 26d 15' 35" (26.259755 deg.)
Angular difference between Flight and Ground position is 2.798549 arcmin
Partial Coding Fraction: 0.5234375 [ including projection effects ]
Duration
T90: 4.67599999904633 +/- 0.611202075251207
Measured from: -0.551999986171722
to: 4.1240000128746 [s; relative to TRIGTIME]
T50: 1.88800001144409 +/- 0.689976831791477
Measured from: 1
to: 2.88800001144409 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 1.75999999046326
to: 2.75999999046326 [s; relative to TRIGTIME]
Total Fluence
Measured from: -0.831999987363815
to: 4.4200000166893 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.151513 0.129819 0.112121 0.015287
0.017117 0.017190 0.015376 0.013750 [error]
Peak 0.043980 0.035495 0.022092 0.012429
0.007564 0.007583 0.006684 0.006060 [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 4.18e-08 6.54e-08 7.72e-08 1.77e-07 2.36e-07 3.58e-07 erg/cm2
Error 8.50e-09 8.19e-09 1.56e-08 7.60e-08 3.55e-08 8.97e-08 erg/cm2
Peak flux Power-law 4.24e-01 3.08e-01 1.48e-01 1.00e-01 9.28e-01 9.80e-01 ph/cm2/s
Error 1.32e-01 6.37e-02 6.10e-02 8.33e-02 1.88e-01 2.03e-01 ph/cm2/s
Fluence Cutoff-PL 4.17e-08 6.55e-08 7.73e-08 1.76e-07 2.36e-07 3.39e-07 erg/cm2
Error 8.51e-09 8.20e-09 1.57e-08 7.55e-08 3.55e-08 1.07e-07 erg/cm2
Peak flux Cutoff-PL 0.00e+00 0.00e+00 0.00e+00 0.00e+00 0.00e+00 0.00e+00 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 Band 4.23e-08 6.52e-08 7.70e-08 1.76e-07 2.36e-07 3.49e-07 erg/cm2
Error 5.28e-09 8.13e-09 1.03e-08 5.13e-08 3.19e-08 4.45e-08 erg/cm2
Peak flux Band 4.03e-01 9.88e-01 0.00e+00 0.00e+00 0.00e+00 0.00e+00 ph/cm2/s
Error 2.01e-01 0.00e+00 0.00e+00 0.00e+00 0.00e+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 1.759 0.250 - - 4.87e-03 7.02e-04 71.331 57
CPL 1.752 0.454 9931.2 5000.0 4.89e-03 1.02e-03 71.335 0
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 2.058 0.488 - - 6.02e-03 1.81e-03 66.455 57
CPL 2.050 0.000 22.3 0.0 5.22e-03 0.00e+00 65.990 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: 6.400000 sec.
T50 in the 50-300 keV band: 2.624000 sec.
=== Table of the duration information ==
Value tstart tstop
T100 5.252 -0.832 4.420
T90 4.676 -0.552 4.124
T50 1.888 1.000 2.888
Peak 1.000 1.760 2.760
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
298.8042 +26.2598 0.0155 26.0 110.4 0.4053 12.4 TRIG_00281993
------------------------------------------
Foreground time interval of the image:
-0.832 4.420 (delta_t = 5.252 [sec])
Background time interval of the image:
-239.160 -0.832 (delta_t = 238.328 [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 -0.832 sec. to 4.420 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.75918 ( -0.244595 0.255571 )
Norm@50keV : 4.871818E-03 ( -7.137470E-04 6.902656E-04) )
------------------------------------------------------------
Chi-Squared = 71.33138 using 59 PHA bins.
Reduced chi-squared = 1.251428 for 57 degrees of freedom
Null hypothesis probability = 9.593E-02
Photon flux (15-150 keV) in 5.252 sec: 0.660996 ( -0.08338 0.083532 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.35858e-07 ( -3.5056e-08 3.59893e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.832 sec. to 4.420 sec.
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.75240 ( -0.644307 0.263127 )
Epeak [keV] : 9931.23 ( -9931.22 68.7705 )
Norm@50keV : 4.889102E-03 ( -7.290617E-04 1.307799E-03) )
------------------------------------------------------------
Chi-Squared = 71.33524 using 59 PHA bins.
but latest trial 5.573611E-03 gives Chi-Squared = 0.271599
Reduced chi-squared = 1.273844 for 56 degrees of freedom
Null hypothesis probability = 8.131E-02
Photon flux (15-150 keV) in 5.252 sec: 0.660742 ( -0.083351 0.083502 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.35983e-07 ( -3.51763e-08 3.58874e-08 ) ergs/cm2
Band function
Time interval is from -0.832 sec. to 4.420 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.75872 ( -8.24128 0.246368 )
beta : -8.27878 ( -1.72122 6.76393 )
Epeak [keV] : 9999.16 ( -9999.06 0.841797 )
Norm@50keV : 4.881521E-03 ( -7.224134E-04 8.151089E-04) )
------------------------------------------------------------
Chi-Squared = 71.33404 using 59 PHA bins.
Reduced chi-squared = 1.296983 for 55 degrees of freedom
Null hypothesis probability = 6.843E-02
Photon flux (15-150 keV) in 5.252 sec: 0.660742 ( -0.083135 0.083476 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.35591e-07 ( -3.44316e-08 2.93487e-08 ) ergs/cm2
Peak spectrum fit using the pre-slew DRM
Power-law model
Time interval is from 1.760 sec. to 2.760 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.05833 ( -0.454165 0.522212 )
Norm@50keV : 6.015935E-03 ( -1.899836E-03 1.726795E-03) )
------------------------------------------------------------
Chi-Squared = 66.45495 using 59 PHA bins.
Reduced chi-squared = 1.165876 for 57 degrees of freedom
Null hypothesis probability = 0.183
Photon flux (15-150 keV) in 1.000 sec: 0.927501 ( -0.188172 0.188169 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.57461e-08 ( -1.4854e-08 1.55737e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 1.760 sec. to 2.760 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.05043 ( )
Epeak [keV] : 22.3006 ( )
Norm@50keV : 5.217161E-03 ( )
------------------------------------------------------------
Chi-Squared = 65.98959 using 59 PHA bins.
Reduced chi-squared = 1.178385 for 56 degrees of freedom
Null hypothesis probability = 0.170
Photon flux (15-150 keV) in 1.000 sec: ( ) ph/cm2/s
Energy fluence (15-150 keV) : 0 ( 0 0 ) ergs/cm2
Band function
Time interval is from 1.760 sec. to 2.760 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.54757 ( -7.81243 7.18757 )
beta : -2.01615 ( -0.522702 0.453431 )
Epeak [keV] : 7.76313 ( -7.66313 9992.24 )
Norm@50keV : 2.309167E-02 ( -0.258404 0.234537 )
------------------------------------------------------------
Chi-Squared = 66.47686 using 59 PHA bins.
Reduced chi-squared = 1.208670 for 55 degrees of freedom
Null hypothesis probability = 0.138
Photon flux (15-150 keV) in 1.000 sec: ( ) ph/cm2/s
Energy fluence (15-150 keV) : 0 ( 0 0 ) ergs/cm2
Plot creation:
Fri Dec 14 01:23:03 EST 2007