batgrbproduct Analysis for Trigger=302506
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): Tue Feb 5 22:34:47 EST 2008
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger302506/GCN5_download_cron
======================================================================
Trigger: 00302506 Segment: 000
BAT Trigger Time: 223890954.304 [s; MET]
Trigger Stop: 223890955.328 [s; MET]
UTC: 2008-02-05T07:55:51.751640 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 98.2192547486492 Dec: 62.7686859637972 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 8.53
Image Trigger?: NO
Rate S/N Ratio: 15.0996688705415 [ if not an image trigger ]
Image S/N Ratio: 8.53
Flight Position: [ source = BAT ]
RA: 98.2192547486492 Dec: 62.7686859637972 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 98.2609154800131 Dec: 62.7821541810855 [deg; J2000]
{ 06h 33m 02.6s , +62d 46' 55.8" }
+/- 1.53703698888576 [arcmin] (estimated 90% radius based on SNR)
+/- 0.687964869330796 [arcmin] (formal 1-sigma fit error)
SNR: 16.4598735983302
RA = 6h 33m 2.6s (98.260915 deg.)
Dec = 62d 46' 56" (62.782154 deg.)
Angular difference between Flight and Ground position is 1.400246 arcmin
Partial Coding Fraction: 0.5234375 [ including projection effects ]
Duration
T90: 106.460000008345 +/- 4.95726093935357
Measured from: -5.4879999756813
to: 100.972000032663 [s; relative to TRIGTIME]
T50: 84.7800000011921 +/- 4.9962742211341
Measured from: 5.14000001549721
to: 89.9200000166893 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 0.224000006914139
to: 1.22400000691414 [s; relative to TRIGTIME]
Total Fluence
Measured from: -10.0760000050068
to: 105.332000017166 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 1.396616 1.403651 0.732437 0.087069
0.067148 0.067055 0.058464 0.049381 [error]
Peak 0.054059 0.061526 0.023801 0.010011
0.008203 0.008200 0.006981 0.005630 [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 4.99e-07 6.45e-07 6.10e-07 1.02e-06 2.09e-06 2.77e-06 erg/cm2
Error 4.90e-08 3.82e-08 6.00e-08 2.09e-07 1.35e-07 2.63e-07 erg/cm2
Peak flux Power-law 6.21e-01 4.59e-01 2.25e-01 1.57e-01 1.38e+00 1.46e+00 ph/cm2/s
Error 1.46e-01 7.34e-02 5.92e-02 7.95e-02 2.23e-01 2.34e-01 ph/cm2/s
Fluence Cutoff-PL 4.89e-07 6.54e-07 6.11e-07 8.20e-07 2.07e-06 2.56e-06 erg/cm2
Error 5.77e-08 4.62e-08 6.13e-08 4.07e-07 1.17e-07 4.51e-07 erg/cm2
Peak flux Cutoff-PL 6.08e-01 4.72e-01 2.26e-01 1.13e-01 1.37e+00 1.42e+00 ph/cm2/s
Error 1.63e-01 9.93e-02 6.46e-02 9.77e-02 1.70e-01 2.67e-01 ph/cm2/s
Fluence Band 4.83e-07 6.51e-07 6.10e-07 8.24e-07 2.07e-06 2.62e-06 erg/cm2
Error 5.71e-08 4.60e-08 6.15e-08 4.07e-07 1.54e-07 4.44e-07 erg/cm2
Peak flux Band 5.87e-01 4.93e-01 2.19e-01 1.18e-01 1.36e+00 1.42e+00 ph/cm2/s
Error 1.74e-01 1.03e-01 5.62e-02 1.19e-01 2.28e-01 2.54e-01 ph/cm2/s
=== Time-averaged spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 2.081 0.122 - - 1.96e-03 1.36e-04 41.991 57
CPL 1.852 0.000 30.8 0.0 2.57e-03 1.53e-03 41.874 0
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 2.026 0.305 - - 9.08e-03 1.81e-03 60.433 57
CPL 1.796 1.094 37.9 4999.7 1.23e-02 7.69e-02 60.345 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: 105.344000 sec.
T50 in the 50-300 keV band: 27.840000 sec.
=== Table of the duration information ==
Value tstart tstop
T100 115.408 -10.076 105.332
T90 106.460 -5.488 100.972
T50 84.780 5.140 89.920
Peak 1.000 0.224 1.224
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
98.2609 +62.7822 0.0116 38.4 -145.0 1.1546 16.5 TRIG_00302506
------------------------------------------
Foreground time interval of the image:
-10.076 14.297 (delta_t = 24.373 [sec])
Background time interval of the image:
-179.203 -79.634 (delta_t = 99.569 [sec])
-78.304 -10.076 (delta_t = 68.228 [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 -10.076 sec. to 105.332 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.08141 ( -0.120004 0.123499 )
Norm@50keV : 1.957224E-03 ( -1.374340E-04 1.354236E-04) )
------------------------------------------------------------
Chi-Squared = 41.99075 using 59 PHA bins.
Reduced chi-squared = 0.7366797 for 57 degrees of freedom
Null hypothesis probability = 0.932
Photon flux (15-150 keV) in 115.4 sec: 0.305127 ( -0.019179 0.019258 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.09491e-06 ( -1.34845e-07 1.35699e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -10.076 sec. to 105.332 sec.
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.85193 ( )
Epeak [keV] : 30.8467 ( )
Norm@50keV : 2.569687E-03 ( -1.332084E-03 1.735340E-03) )
------------------------------------------------------------
Chi-Squared = 41.87393 using 59 PHA bins.
but latest trial 1.904428E-03 gives Chi-Squared = 0.308491
Reduced chi-squared = 0.7477487 for 56 degrees of freedom
Null hypothesis probability = 0.920
Photon flux (15-150 keV) in 115.4 sec: 0.302514 ( -0.019171 0.018929 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.07293e-06 ( -1.60833e-07 7.2425e-08 ) ergs/cm2
Band function
Time interval is from -10.076 sec. to 105.332 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.71300 ( -2.24352 8.23275 )
beta : -2.12670 ( -0.123470 0.120023 )
Epeak [keV] : 25.8729 ( -25.7729 9974.13 )
Norm@50keV : 3.360493E-03 ( -1.867864E-02 1.840696E-02) )
------------------------------------------------------------
Chi-Squared = 42.28710 using 59 PHA bins.
Reduced chi-squared = 0.7688563 for 55 degrees of freedom
Null hypothesis probability = 0.895
Photon flux (15-150 keV) in 115.4 sec: 0.302519 ( -0.021021 0.020894 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.06972e-06 ( -1.56402e-07 1.51705e-07 ) ergs/cm2
Peak spectrum fit using the pre-slew DRM
Power-law model
Time interval is from 0.224 sec. to 1.224 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.02634 ( -0.292143 0.318150 )
Norm@50keV : 9.082811E-03 ( -1.849898E-03 1.771701E-03) )
------------------------------------------------------------
Chi-Squared = 60.43256 using 59 PHA bins.
Reduced chi-squared = 1.060220 for 57 degrees of freedom
Null hypothesis probability = 0.353
Photon flux (15-150 keV) in 1.000 sec: 1.37918 ( -0.22265 0.22284 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.38432e-08 ( -1.55359e-08 1.59599e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.224 sec. to 1.224 sec.
Parameters : value lower 90% higher 90%
Photon index: 1.79564 ( -1.85710 0.331623 )
Epeak [keV] : 37.8555 ( -37.2557 9962.14 )
Norm@50keV : 1.232777E-02 ( -1.232777E-02 0.141554 )
------------------------------------------------------------
Chi-Squared = 60.34454 using 59 PHA bins.
but latest trial 2.12726 gives Chi-Squared = 0.165596
but latest trial 0.674587 gives Chi-Squared = 0.158138
Reduced chi-squared = 1.077581 for 56 degrees of freedom
Null hypothesis probability = 0.322
Photon flux (15-150 keV) in 1.000 sec: 1.36981 ( -0.11706 0.22332 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.20413e-08 ( -1.84896e-08 1.74937e-08 ) ergs/cm2
Band function
Time interval is from 0.224 sec. to 1.224 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.37492 ( -8.62508 3.51800 )
beta : -2.28140 ( -7.71860 0.520287 )
Epeak [keV] : 36.8736 ( -36.7736 232.215 )
Norm@50keV : 2.240369E-02 ( -9.967863E-03 1269.88 )
------------------------------------------------------------
Chi-Squared = 59.95060 using 59 PHA bins.
Reduced chi-squared = 1.090011 for 55 degrees of freedom
Null hypothesis probability = 0.301
Photon flux (15-150 keV) in 1.000 sec: 1.35909 ( -0.22977 0.22679 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.13841e-08 ( -1.64866e-08 1.60039e-08 ) ergs/cm2
Plot creation:
Tue Feb 5 22:59:16 EST 2008