batgrbproduct Analysis for Trigger=279418
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 21:40:13 EST 2007
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger279418/GCN5_download_cron
======================================================================
Trigger: 00279418 Segment: 000
BAT Trigger Time: 201042026.752 [s; MET]
Trigger Stop: 201042027.776 [s; MET]
UTC: 2007-05-16T21:00:24.792620 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 256.569892291802 Dec: -43.0312373655654 [deg; J2000]
Catalogged Source?: YES
Point Source?: YES
GRB Indicated?: NO [ by BAT flight software ]
Image S/N Ratio: 7.44
Image Trigger?: NO
Rate S/N Ratio: 9.4339811320566 [ if not an image trigger ]
Image S/N Ratio: 7.44
Flight Position: [ source = BAT ]
RA: 256.569892291802 Dec: -43.0312373655654 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 256.551056909043 Dec: -43.0569971159623 [deg; J2000]
{ 17h 06m 12.3s , -43d 03' 25.2" }
+/- 3.39974869156029 [arcmin] (estimated 90% radius based on SNR)
+/- 2.46238245278211 [arcmin] (formal 1-sigma fit error)
SNR: 5.29552038073527
RA = 17h 6m 12.3s (256.551057 deg.)
Dec = -43d 3' 25" (-43.056997 deg.)
Angular difference between Flight and Ground position is 1.752423 arcmin
Partial Coding Fraction: 0.8359375 [ including projection effects ]
Duration
T90: 6 +/- 2.23606797749979
Measured from: -3.75200000405312
to: 2.24799999594688 [s; relative to TRIGTIME]
T50: 3 +/- 2.23606797749979
Measured from: -1.75200000405312
to: 1.24799999594688 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: -1.75200000405312
to: -0.752000004053116 [s; relative to TRIGTIME]
Total Fluence
Measured from: -3.75200000405312
to: 3.24799999594688 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.226623 0.004722 0.010906 -0.015797
0.015724 0.013929 0.011611 0.010265 [error]
Peak 0.032974 0.011990 0.001436 0.001401
0.006037 0.005228 0.004327 0.003897 [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 6.99e-08 1.34e-08 1.24e-09 1.26e-10 8.46e-08 8.46e-08 erg/cm2
Error 1.10e-08 5.57e-09 1.18e-09 2.36e-10 1.48e-08 1.48e-08 erg/cm2
Peak flux Power-law 3.72e-01 8.18e-02 9.12e-03 1.12e-03 4.63e-01 4.64e-01 ph/cm2/s
Error 1.08e-01 5.61e-02 1.57e-02 4.48e-03 1.38e-01 1.38e-01 ph/cm2/s
Fluence Cutoff-PL 7.68e-08 7.17e-09 3.18e-12 7.42e-20 8.40e-08 8.39e-08 erg/cm2
Error 1.18e-08 4.22e-09 4.22e-11 3.85e-14 1.31e-08 1.31e-08 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 6.89e-08 1.32e-08 1.24e-09 8.37e-08 0.00e+00 0.00e+00 erg/cm2
Error 1.08e-08 5.54e-09 1.48e-08 0.00e+00 0.00e+00 0.00e+00 erg/cm2
Peak flux Band 3.69e-01 8.63e-02 1.04e-02 1.39e-03 6.54e+00 3.37e-01 ph/cm2/s
Error 1.04e-01 2.40e-02 1.22e-02 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 5.263 0.732 - - 1.97e-04 1.66e-04 55.657 57
CPL -2.024 0.000 10.8 6.4 3.24e+02 0.00e+00 50.049 0
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 4.164 1.469 - - 6.51e-04 8.64e-04 42.672 57
CPL 1.871 0.000 1.4 0.0 3.42e-02 0.00e+00 43.313 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: 0.000000 sec.
T50 in the 50-300 keV band: 0.000000 sec.
=== Table of the duration information ==
Value tstart tstop
T100 7.000 -3.752 3.248
T90 6.000 -3.752 2.248
T50 3.000 -1.752 1.248
Peak 1.000 -1.752 -0.752
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
256.5511 -43.0570 0.0360 21.8 148.7 0.2064 5.3 TRIG_00279418
------------------------------------------
Foreground time interval of the image:
-3.752 3.248 (delta_t = 7.000 [sec])
Background time interval of the image:
-10.752 -3.752 (delta_t = 7.000 [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 -3.752 sec. to 3.248 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 5.26338 ( -0.525043 0.938812 )
Norm@50keV : 1.970118E-04 ( -1.970118E-04 1.359182E-04) )
------------------------------------------------------------
Chi-Squared = 55.65685 using 59 PHA bins.
Reduced chi-squared = 0.9764360 for 57 degrees of freedom
Null hypothesis probability = 0.526
Photon flux (15-150 keV) in 7.000 sec: 0.389363 ( -0.062315 0.062381 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.45978e-08 ( -1.46305e-08 1.49835e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -3.752 sec. to 3.248 sec.
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -2.02401 ( )
Epeak [keV] : 10.7857 ( -10.8294 1.90726 )
Norm@50keV : 324.066 ( )
------------------------------------------------------------
Chi-Squared = 50.04914 using 59 PHA bins.
but latest trial 12.8854 gives Chi-Squared = 2.72199
Reduced chi-squared = 0.8937346 for 56 degrees of freedom
Null hypothesis probability = 0.698
Photon flux (15-150 keV) in 7.000 sec: 0.388971 ( -0.062271 0.062339 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.39559e-08 ( -1.30872e-08 1.31649e-08 ) ergs/cm2
Band function
Time interval is from -3.752 sec. to 3.248 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -9.29637 ( -0.703629 14.2964 )
beta : -5.42526 ( -0.754622 0.669479 )
Epeak [keV] : 369.931 ( -369.831 9630.07 )
Norm@50keV : 2.273931E-02 ( -1.273957E-02 2.178973E-02) )
------------------------------------------------------------
Chi-Squared = 55.51326 using 59 PHA bins.
Reduced chi-squared = 1.009332 for 55 degrees of freedom
Null hypothesis probability = 0.455
Photon flux (15-150 keV) in 7.000 sec: 0.402983 ( -0.061759 0.061792 ) 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 -1.752 sec. to -0.752 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 4.16381 ( -1.09909 1.83961 )
Norm@50keV : 6.505666E-04 ( -6.505666E-04 1.077571E-03) )
------------------------------------------------------------
Chi-Squared = 42.67203 using 59 PHA bins.
Reduced chi-squared = 0.7486321 for 57 degrees of freedom
Null hypothesis probability = 0.921
Photon flux (15-150 keV) in 1.000 sec: 0.463442 ( -0.137708 0.137555 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.61835e-08 ( -5.9086e-09 6.8269e-09 ) ergs/cm2
Cutoff power-law model
Time interval is from -1.752 sec. to -0.752 sec.
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.87145 ( )
Epeak [keV] : 1.42939 ( )
Norm@50keV : 3.424468E-02 ( )
------------------------------------------------------------
Chi-Squared = 43.31339 using 59 PHA bins.
but latest trial 0.841433 gives Chi-Squared = 0.401138
Reduced chi-squared = 0.7734534 for 56 degrees of freedom
Null hypothesis probability = 0.892
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 -1.752 sec. to -0.752 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.94340 ( -4.97477 10.0252 )
beta : -3.86259 ( -1.83941 1.10107 )
Epeak [keV] : 0.358569 ( -0.258569 9999.64 )
Norm@50keV : 9.150593E-02 ( -7.610139E-02 0.146579 )
------------------------------------------------------------
Chi-Squared = 42.86409 using 59 PHA bins.
Reduced chi-squared = 0.7793470 for 55 degrees of freedom
Null hypothesis probability = 0.883
Photon flux (15-150 keV) in 1.000 sec: 6.53542 ( ) ph/cm2/s
Energy fluence (15-150 keV) : 0 ( 0 0 ) ergs/cm2
Plot creation:
Thu Dec 13 21:44:03 EST 2007