batgrbproduct Analysis for Trigger=208870
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): Mon Dec 31 22:36:03 EST 2007
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger208870/SDC
======================================================================
Trigger: 00208870 Segment: 000
BAT Trigger Time: 168659593.408 [s; MET]
Trigger Stop: 168659594.432 [s; MET]
UTC: 2006-05-07T01:53:12.230320 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 89.9718765738037 Dec: 75.2369661619308 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 7.19
Image Trigger?: NO
Rate S/N Ratio: 13.9283882771841 [ if not an image trigger ]
Image S/N Ratio: 7.19
Flight Position: [ source = BAT ]
RA: 89.9718765738037 Dec: 75.2369661619308 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 89.91075236342 Dec: 75.2449237328652 [deg; J2000]
{ 05h 59m 38.6s , +75d 14' 41.7" }
+/- 1.15636960817329 [arcmin] (estimated 90% radius based on SNR)
+/- 0.375890542072786 [arcmin] (formal 1-sigma fit error)
SNR: 24.7161192229184
RA = 5h 59m 38.6s (89.910752 deg.)
Dec = 75d 14' 42" (75.244924 deg.)
Angular difference between Flight and Ground position is 1.049229 arcmin
Partial Coding Fraction: 0.328125 [ including projection effects ]
Duration
T90: 183.263999998569 +/- 6.67312250940084
Measured from: -3.52799999713898
to: 179.736000001431 [s; relative to TRIGTIME]
T50: 114.344000011683 +/- 7.28259650942039
Measured from: 13.5960000157356
to: 127.940000027418 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 1.24400001764297
to: 2.24400001764297 [s; relative to TRIGTIME]
Total Fluence
Measured from: -11.0239999890327
to: 192.351999998093 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 2.587282 2.964220 1.747214 0.373225
0.108286 0.112182 0.098895 0.083517 [error]
Peak 0.049452 0.053313 0.041148 0.005736
0.008249 0.008764 0.008070 0.006158 [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 8.43e-07 1.27e-06 1.42e-06 3.04e-06 4.45e-06 6.57e-06 erg/cm2
Error 7.06e-08 6.27e-08 9.88e-08 4.53e-07 2.30e-07 5.30e-07 erg/cm2
Peak flux Power-law 4.82e-01 4.27e-01 2.60e-01 2.41e-01 1.27e+00 1.41e+00 ph/cm2/s
Error 1.24e-01 7.29e-02 6.22e-02 1.11e-01 2.16e-01 2.41e-01 ph/cm2/s
Fluence Cutoff-PL 7.92e-07 1.31e-06 1.45e-06 1.81e-06 4.33e-06 5.32e-06 erg/cm2
Error 8.63e-08 7.54e-08 1.06e-07 9.42e-07 3.23e-07 7.02e-07 erg/cm2
Peak flux Cutoff-PL 4.33e-01 4.70e-01 2.74e-01 1.02e-01 1.25e+00 1.28e+00 ph/cm2/s
Error 1.11e-01 9.95e-02 7.30e-02 1.53e-01 2.21e-01 2.71e-01 ph/cm2/s
Fluence Band 7.83e-07 1.30e-06 1.45e-06 1.81e-06 4.32e-06 5.53e-06 erg/cm2
Error 8.54e-08 7.51e-08 1.06e-07 6.87e-07 2.59e-07 1.05e-06 erg/cm2
Peak flux Band 4.30e-01 4.72e-01 2.72e-01 1.33e-01 1.25e+00 1.31e+00 ph/cm2/s
Error 1.46e-01 9.98e-02 7.44e-02 1.82e-01 2.19e-01 2.73e-01 ph/cm2/s
=== Time-averaged spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.830 0.092 - - 2.38e-03 1.21e-04 65.399 57
CPL 1.421 0.364 69.6 246.6 3.83e-03 1.64e-03 62.398 0
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.714 0.288 - - 9.53e-03 1.78e-03 49.787 57
CPL 0.907 1.413 63.4 4977.3 2.59e-02 9.00e-02 48.593 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: 183.296000 sec.
T50 in the 50-300 keV band: 115.136000 sec.
=== Table of the duration information ==
Value tstart tstop
T100 203.376 -11.024 192.352
T90 183.264 -3.528 179.736
T50 114.344 13.596 127.940
Peak 1.000 1.244 2.244
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
89.9108 +75.2449 0.0078 32.6 -84.7 6.8758 24.7 TRIG_00208870
------------------------------------------
Foreground time interval of the image:
-11.024 175.397 (delta_t = 186.421 [sec])
Background time interval of the image:
-239.408 -11.024 (delta_t = 228.384 [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 -11.024 sec. to 192.352 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.83027 ( -9.138739E-02 9.251142E-02) )
Norm@50keV : 2.377522E-03 ( -1.214964E-04 1.206475E-04) )
------------------------------------------------------------
Chi-Squared = 65.39904 using 59 PHA bins.
Reduced chi-squared = 1.147352 for 57 degrees of freedom
Null hypothesis probability = 0.208
Photon flux (15-150 keV) in 203.4 sec: 0.331542 ( -0.016963 0.017021 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.44773e-06 ( -2.28845e-07 2.30981e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -11.024 sec. to 192.352 sec.
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.42084 ( -0.348204 0.380408 )
Epeak [keV] : 69.6182 ( -13.9860 479.142 )
Norm@50keV : 3.826154E-03 ( -1.407489E-03 1.866950E-03) )
------------------------------------------------------------
Chi-Squared = 62.39789 using 59 PHA bins.
but latest trial 1.80125 gives Chi-Squared = 2.33037
Reduced chi-squared = 1.114248 for 56 degrees of freedom
Null hypothesis probability = 0.259
Photon flux (15-150 keV) in 203.4 sec: 0.323934 ( -0.018434 0.018416 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.32813e-06 ( -2.60942e-07 3.84507e-07 ) ergs/cm2
Band function
Time interval is from -11.024 sec. to 192.352 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.46772 ( -0.355357 0.391785 )
beta : -9.27264 ( -0.727356 7.44081 )
Epeak [keV] : 72.2281 ( -16.5502 410.162 )
Norm@50keV : 3.628402E-03 ( -1.203817E-03 2.041081E-03) )
------------------------------------------------------------
Chi-Squared = 62.35376 using 59 PHA bins.
Reduced chi-squared = 1.133705 for 55 degrees of freedom
Null hypothesis probability = 0.231
Photon flux (15-150 keV) in 203.4 sec: 0.323954 ( -0.018443 0.018475 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.32323e-06 ( -2.60555e-07 2.58135e-07 ) ergs/cm2
Peak spectrum fit using the pre-slew DRM
Power-law model
Time interval is from 1.244 sec. to 2.244 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.71376 ( -0.280029 0.296865 )
Norm@50keV : 9.526943E-03 ( -1.802142E-03 1.755361E-03) )
------------------------------------------------------------
Chi-Squared = 49.78691 using 59 PHA bins.
Reduced chi-squared = 0.8734546 for 57 degrees of freedom
Null hypothesis probability = 0.740
Photon flux (15-150 keV) in 1.000 sec: 1.27143 ( -0.21574 0.21586 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.81003e-08 ( -1.70516e-08 1.74127e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 1.244 sec. to 2.244 sec.
Parameters : value lower 90% higher 90%
Photon index: 0.906775 ( -1.66501 1.16133 )
Epeak [keV] : 63.3726 ( -17.9839 9936.63 )
Norm@50keV : 2.593142E-02 ( -1.000000E-02 0.170043 )
------------------------------------------------------------
Chi-Squared = 48.59295 using 59 PHA bins.
but latest trial 27.5876 gives Chi-Squared = 2.73542
but latest trial 7.087054E-03 gives Chi-Squared = 6.09271
Reduced chi-squared = 0.8677313 for 56 degrees of freedom
Null hypothesis probability = 0.748
Photon flux (15-150 keV) in 1.000 sec: 1.24663 ( -0.22203 0.22028 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.38645e-08 ( -1.82385e-08 1.87695e-08 ) ergs/cm2
Band function
Time interval is from 1.244 sec. to 2.244 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.842128 ( -9.15787 3.51651 )
beta : -2.53450 ( -7.46550 1.02269 )
Epeak [keV] : 61.0733 ( -60.9733 320.676 )
Norm@50keV : 2.832640E-02 ( -1.566296E-02 1456.82 )
------------------------------------------------------------
Chi-Squared = 48.48639 using 59 PHA bins.
Reduced chi-squared = 0.8815708 for 55 degrees of freedom
Null hypothesis probability = 0.720
Photon flux (15-150 keV) in 1.000 sec: 1.24558 ( -0.22076 0.21766 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.4344e-08 ( -1.53788e-08 1.8023e-08 ) ergs/cm2
Plot creation:
Mon Dec 31 22:58:54 EST 2007