batgrbproduct Analysis for Trigger=318094
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): Sun Jul 27 12:29:20 EDT 2008
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger318094/GCN5_download_cron
======================================================================
Trigger: 00318094 Segment: 000
BAT Trigger Time: 238831062.336 [s; MET]
Trigger Stop: 238831067.84 [s; MET]
UTC: 2008-07-27T05:57:39.363900 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 208.388757842545 Dec: -18.5488483391044 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 7.3
Image Trigger?: NO
Rate S/N Ratio: 14.422205101856 [ if not an image trigger ]
Image S/N Ratio: 7.3
Flight Position: [ source = BAT ]
RA: 208.388757842545 Dec: -18.5488483391044 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 208.416380284615 Dec: -18.5718420085568 [deg; J2000]
{ 13h 53m 39.9s , -18d 34' 18.6" }
+/- 2.39435934121462 [arcmin] (estimated 90% radius based on SNR)
+/- 1.1996653999803 [arcmin] (formal 1-sigma fit error)
SNR: 8.73814683747778
Angular difference between Flight and Ground position is 2.090897 arcmin
Partial Coding Fraction: 0.9765625 [ including projection effects ]
Duration
T90: 4.91600000858307 +/- 1.00712658759602
Measured from: 0.0559999942779541
to: 4.97200000286102 [s; relative to TRIGTIME]
T50: 2.58799999952316 +/- 1.3130879625801
Measured from: 1.09600001573563
to: 3.68400001525879 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 1.20000001788139
to: 2.20000001788139 [s; relative to TRIGTIME]
Total Fluence
Measured from: -0.139999985694885
to: 5.14800000190735 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.045554 0.068484 0.069502 0.022855
0.013834 0.012244 0.011265 0.010005 [error]
Peak 0.012621 0.012939 0.014094 0.016293
0.006017 0.005343 0.004923 0.004417 [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 1.32e-08 2.83e-08 4.76e-08 1.84e-07 1.31e-07 2.75e-07 erg/cm2
Error 4.66e-09 5.89e-09 1.08e-08 9.69e-08 2.71e-08 1.03e-07 erg/cm2
Peak flux Power-law 3.79e-02 7.56e-02 1.17e-01 4.01e-01 3.28e-01 6.31e-01 ph/cm2/s
Error 5.18e-02 6.65e-02 7.75e-02 4.44e-01 2.27e-01 3.89e-01 ph/cm2/s
Fluence Cutoff-PL 1.17e-08 2.92e-08 4.96e-08 9.77e-08 1.27e-07 1.86e-07 erg/cm2
Error 5.67e-09 6.63e-09 1.23e-08 1.43e-07 2.94e-08 1.37e-07 erg/cm2
Peak flux Cutoff-PL 3.77e-02 7.55e-02 1.17e-01 3.99e-01 3.27e-01 6.29e-01 ph/cm2/s
Error 5.17e-02 6.65e-02 3.76e-02 4.41e-01 2.27e-01 3.87e-01 ph/cm2/s
Fluence Band 1.17e-08 2.91e-08 4.94e-08 9.88e-08 1.27e-07 2.07e-07 erg/cm2
Error 5.72e-09 6.59e-09 1.23e-08 1.31e-07 2.95e-08 1.37e-07 erg/cm2
Peak flux Band 3.77e-02 7.55e-02 1.17e-01 3.99e-01 3.27e-01 6.29e-01 ph/cm2/s
Error 5.17e-02 6.64e-02 3.76e-02 9.03e-01 2.27e-01 4.00e-01 ph/cm2/s
=== Time-averaged spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.247 0.341 - - 2.47e-03 4.53e-04 43.537 57
CPL 0.773 1.707 141.4 5000.0 4.09e-03 1.03e-02 43.158 0
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 0.366 0.997 - - 2.70e-03 1.40e-03 47.039 57
CPL 0.338 1.029 9975.3 0.0 2.53e-03 1.40e-03 47.173 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: 0.000000 sec.
T50 in the 50-300 keV band: 0.000000 sec.
=== Table of the duration information ==
Value tstart tstop
T100 5.288 -0.140 5.148
T90 4.916 0.056 4.972
T50 2.588 1.096 3.684
Peak 1.000 1.200 2.200
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
208.4164 -18.5718 0.0218 16.9 -141.7 0.2141 8.7 TRIG_00318094
------------------------------------------
Foreground time interval of the image:
-0.140 5.148 (delta_t = 5.288 [sec])
Background time interval of the image:
-239.336 -56.308 (delta_t = 183.028 [sec])
-55.336 -0.140 (delta_t = 55.196 [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 -0.140 sec. to 5.148 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.24666 ( -0.342886 0.338928 )
Norm@50keV : 2.471522E-03 ( -4.536342E-04 4.532856E-04) )
------------------------------------------------------------
Chi-Squared = 43.53725 using 59 PHA bins.
Reduced chi-squared = 0.7638114 for 57 degrees of freedom
Null hypothesis probability = 0.905
Photon flux (15-150 keV) in 5.288 sec: 0.292157 ( -0.05509 0.055381 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.30925e-07 ( -2.67821e-08 2.73416e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.140 sec. to 5.148 sec.
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.772602 ( -1.70572 1.70850 )
Epeak [keV] : 141.354 ( -141.344 9858.65 )
Norm@50keV : 4.091874E-03 ( -2.031965E-03 1.847107E-02) )
------------------------------------------------------------
Chi-Squared = 43.15781 using 59 PHA bins.
but latest trial 2.47633 gives Chi-Squared = 2.58552
Reduced chi-squared = 0.7706751 for 56 degrees of freedom
Null hypothesis probability = 0.896
Photon flux (15-150 keV) in 5.288 sec: 0.284134 ( -0.059478 0.029949 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.26619e-07 ( -2.93748e-08 2.95002e-08 ) ergs/cm2
Band function
Time interval is from -0.140 sec. to 5.148 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.755732 ( -2.22560 1.68857 )
beta : -8.81132 ( -1.18868 7.88149 )
Epeak [keV] : 138.152 ( -138.052 9861.85 )
Norm@50keV : 4.164515E-03 ( -4.164516E-03 1.770208E-02) )
------------------------------------------------------------
Chi-Squared = 43.15833 using 59 PHA bins.
Reduced chi-squared = 0.7846968 for 55 degrees of freedom
Null hypothesis probability = 0.876
Photon flux (15-150 keV) in 5.288 sec: 0.284199 ( -0.059545 0.059267 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.26629e-07 ( -2.94441e-08 2.95932e-08 ) ergs/cm2
Peak spectrum fit using the pre-slew DRM
Power-law model
Time interval is from 1.200 sec. to 2.200 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.366482 ( -1.15540 0.837627 )
Norm@50keV : 2.697527E-03 ( -1.539565E-03 1.251098E-03) )
------------------------------------------------------------
Chi-Squared = 47.03912 using 59 PHA bins.
Reduced chi-squared = 0.8252478 for 57 degrees of freedom
Null hypothesis probability = 0.824
Photon flux (15-150 keV) in 1.000 sec: 0.327758 ( -0.327758 0.126335 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.8879e-08 ( -1.2773e-08 1.26776e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 1.200 sec. to 2.200 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.337801 ( -1.17686 0.880764 )
Epeak [keV] : 9975.27 ( )
Norm@50keV : 2.527236E-03 ( -1.540945E-03 1.255692E-03) )
------------------------------------------------------------
Chi-Squared = 47.17325 using 59 PHA bins.
Reduced chi-squared = 0.8423795 for 56 degrees of freedom
Null hypothesis probability = 0.793
Photon flux (15-150 keV) in 1.000 sec: 0.327476 ( -0.327476 0.126278 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.89011e-08 ( -1.27923e-08 1.26925e-08 ) ergs/cm2
Band function
Time interval is from 1.200 sec. to 2.200 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.948757 ( -2.613068E-04 14.9997 )
beta : -0.652868 ( -0.830978 1.16279 )
Epeak [keV] : 8.90541 ( -8.80541 9991.09 )
Norm@50keV : 5.218582E-03 ( -0.367912 0.168971 )
------------------------------------------------------------
Chi-Squared = 47.34018 using 59 PHA bins.
Reduced chi-squared = 0.8607306 for 55 degrees of freedom
Null hypothesis probability = 0.759
Photon flux (15-150 keV) in 1.000 sec: 0.327478 ( -0.327478 0.126276 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.88752e-08 ( -1.27846e-08 1.2696e-08 ) ergs/cm2
Plot creation:
Sun Jul 27 12:59:53 EDT 2008