batgrbproduct Analysis for Trigger=312579
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): Wed May 28 19:36:55 EDT 2008
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger312579/GCN5_download_cron
======================================================================
Trigger: 00312579 Segment: 000
BAT Trigger Time: 233655706.528 [s; MET]
Trigger Stop: 233655706.56 [s; MET]
UTC: 2008-05-28T08:21:43.704560 [includes UTCF correction]
Where From?: (*SHORT BURST*) TDRSS scaled map message
BAT
RA: 248.967167947589 Dec: -47.5927372406783 [deg; J2000]
Catalogged Source?: YES
Point Source?: YES
GRB Indicated?: NO [ by BAT flight software ]
Image S/N Ratio: 10.59
Image Trigger?: NO
Rate S/N Ratio: 37.841775856849 [ if not an image trigger ]
Image S/N Ratio: 10.59
Flight Position: [ source = BAT ]
RA: 248.967167947589 Dec: -47.5927372406783 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 248.977798157898 Dec: -47.5880364999673 [deg; J2000]
{ 16h 35m 54.7s , -47d 35' 16.9" }
+/- 1.5004932007499 [arcmin] (estimated 90% radius based on SNR)
+/- 0.522050503653956 [arcmin] (formal 1-sigma fit error)
SNR: 17.0355232426315
Angular difference between Flight and Ground position is 0.514378 arcmin
Partial Coding Fraction: 0.1035156 [ including projection effects ]
Duration
T90: 0.26800000667572 +/- 0.0494772521259706
Measured from: -0.00799998641014099
to: 0.260000020265579 [s; relative to TRIGTIME]
T50: 0.0719999969005585 +/- 0.0243310406358178
Measured from: 0.0200000107288361
to: 0.0920000076293945 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: -0.354000002145767
to: 0.645999997854233 [s; relative to TRIGTIME]
Total Fluence
Measured from: -0.0160000026226044
to: 0.303999990224838 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.377146 0.195742 0.040013 0.000991
0.025135 0.018422 0.010310 0.006746 [error]
Peak 0.377151 0.194476 0.038930 0.000991
0.025135 0.018465 0.010367 0.006746 [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 1.38e-07 8.35e-08 3.24e-08 1.68e-08 2.62e-07 2.70e-07 erg/cm2
Error 1.67e-08 9.96e-09 7.45e-09 6.80e-09 2.77e-08 2.95e-08 erg/cm2
Peak flux Power-law 1.43e+01 4.87e+00 9.41e-01 2.14e-01 2.02e+01 2.03e+01 ph/cm2/s
Error 1.76e+00 5.69e-01 2.13e-01 8.29e-02 2.15e+00 2.15e+00 ph/cm2/s
Fluence Cutoff-PL 1.38e-07 8.36e-08 3.24e-08 1.67e-08 2.62e-07 2.69e-07 erg/cm2
Error 1.67e-08 9.97e-09 7.45e-09 6.75e-09 2.77e-08 2.95e-08 erg/cm2
Peak flux Cutoff-PL 1.42e+01 4.87e+00 9.40e-01 2.12e-01 2.02e+01 2.03e+01 ph/cm2/s
Error 1.76e+00 5.69e-01 2.13e-01 8.24e-02 2.15e+00 2.15e+00 ph/cm2/s
Fluence Band 1.36e-07 8.35e-08 3.28e-08 1.73e-08 2.61e-07 2.70e-07 erg/cm2
Error 1.49e-08 9.13e-09 3.70e-09 3.48e-09 2.70e-08 2.81e-08 erg/cm2
Peak flux Band 1.41e+01 5.45e+00 7.39e-01 3.69e-02 2.03e+01 2.04e+01 ph/cm2/s
Error 1.92e+00 8.15e-01 5.89e-02 2.09e+00 2.14e+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 3.366 0.213 - - 5.64e-02 9.98e-03 61.133 57
CPL 1.149 1.895 11.5 9.7 1.98e+00 1.58e+02 52.471 0
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 3.373 0.216 - - 5.53e-02 9.94e-03 61.257 57
CPL 0.863 2.095 13.3 10.4 3.22e+00 3.18e+02 52.008 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 0.320 -0.016 0.304
T90 0.268 -0.008 0.260
T50 0.072 0.020 0.092
Peak 1.000 -0.354 0.646
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
248.9778 -47.5880 0.0113 39.5 64.8 0.6491 17.0 TRIG_00312579
------------------------------------------
Foreground time interval of the image:
-0.016 0.304 (delta_t = 0.320 [sec])
Background time interval of the image:
-227.027 -57.213 (delta_t = 169.814 [sec])
-56.528 -0.016 (delta_t = 56.512 [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 -0.016 sec. to 0.304 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 3.36570 ( -0.204372 0.221559 )
Norm@50keV : 5.643921E-02 ( -9.939387E-03 1.002481E-02) )
------------------------------------------------------------
Chi-Squared = 61.13298 using 59 PHA bins.
Reduced chi-squared = 1.072508 for 57 degrees of freedom
Null hypothesis probability = 0.330
Photon flux (15-150 keV) in 0.3200 sec: 20.4975 ( -2.1721 2.1731 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.62391e-07 ( -2.76947e-08 2.77766e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.016 sec. to 0.304 sec.
Photon index: 1.14889 ( -2.95930 0.831090 )
Epeak [keV] : 11.5036 ( -10.2421 9.11095 )
Norm@50keV : 1.98098 ( -1.98098 314.818 )
------------------------------------------------------------
Chi-Squared = 52.47075 using 59 PHA bins.
but latest trial 1.97997 gives Chi-Squared = 1.66358
but latest trial 1.27016 gives Chi-Squared = 0.653881
but latest trial 20.6131 gives Chi-Squared = 2.67274
Reduced chi-squared = 0.9369776 for 56 degrees of freedom
Null hypothesis probability = 0.609
Photon flux (15-150 keV) in 0.3200 sec: 20.4887 ( -2.1704 2.1726 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.6243e-07 ( -2.76989e-08 2.77798e-08 ) ergs/cm2
Band function
Time interval is from -0.016 sec. to 0.304 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.69816 ( -4.879141E-02 0.453911 )
beta : -9.27874 ( -5.73831 14.2617 )
Epeak [keV] : 12.7884 ( -15.6280 2.79202 )
Norm@50keV : 0.283156 ( -44234.0 20008.3 )
------------------------------------------------------------
Chi-Squared = 92.52045 using 59 PHA bins.
Reduced chi-squared = 1.682190 for 55 degrees of freedom
Null hypothesis probability = 1.158E-03
Photon flux (15-150 keV) in 0.3200 sec: 20.5606 ( -2.1556 2.2391 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.60823e-07 ( -2.69539e-08 2.70403e-08 ) ergs/cm2
Peak spectrum fit using the pre-slew DRM
Power-law model
Time interval is from -0.016 sec. to 0.308 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 3.37274 ( -0.206974 0.224385 )
Norm@50keV : 5.533695E-02 ( -9.883672E-03 9.996593E-03) )
------------------------------------------------------------
Chi-Squared = 61.25690 using 59 PHA bins.
Reduced chi-squared = 1.074683 for 57 degrees of freedom
Null hypothesis probability = 0.326
Photon flux (15-150 keV) in 0.3240 sec: 20.2095 ( -2.1465 2.1474 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.61531e-07 ( -2.77616e-08 2.78721e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.016 sec. to 0.308 sec.
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.863070 ( -3.07239 1.11755 )
Epeak [keV] : 13.3033 ( -13.2933 7.50287 )
Norm@50keV : 3.22302 ( -3.22302 631.893 )
------------------------------------------------------------
Chi-Squared = 52.00789 using 59 PHA bins.
but latest trial 20.8061 gives Chi-Squared = 2.50955
Reduced chi-squared = 0.9287124 for 56 degrees of freedom
Null hypothesis probability = 0.627
Photon flux (15-150 keV) in 0.3240 sec: 20.2010 ( -2.145 2.1467 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.61581e-07 ( -2.77736e-08 2.78672e-08 ) ergs/cm2
Band function
Time interval is from -0.016 sec. to 0.308 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.69748 ( -8.30252 6.69748 )
beta : -9.29269 ( -5.98264 0.532153 )
Epeak [keV] : 12.6738 ( -16.2084 2.67219 )
Norm@50keV : 0.278788 ( -47519.4 12928.9 )
------------------------------------------------------------
Chi-Squared = 92.06863 using 59 PHA bins.
Reduced chi-squared = 1.673975 for 55 degrees of freedom
Null hypothesis probability = 1.282E-03
Photon flux (15-150 keV) in 0.3240 sec: 20.2767 ( -2.052 2.1283 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.55805e-07 ( -2.72484e-08 2.58069e-08 ) ergs/cm2
Plot creation:
Wed May 28 20:22:00 EDT 2008