batgrbproduct Analysis for Trigger=308812
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 Apr 9 14:19:57 EDT 2008
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger308812/GCN5_download_cron
======================================================================
Trigger: 00308812 Segment: 000
BAT Trigger Time: 229396980.288 [s; MET]
Trigger Stop: 229396980.8 [s; MET]
UTC: 2008-04-09T01:22:57.584260 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 84.3330381966349 Dec: 5.08532726901622 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 14.13
Image Trigger?: NO
Rate S/N Ratio: 19.8494332412792 [ if not an image trigger ]
Image S/N Ratio: 14.13
Flight Position: [ source = BAT ]
RA: 84.3330381966349 Dec: 5.08532726901622 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 84.3035363954213 Dec: 5.07585078237677 [deg; J2000]
{ 05h 37m 12.8s , +05d 04' 33.1" }
+/- 1.81642060564332 [arcmin] (estimated 90% radius based on SNR)
+/- 0.750105367157048 [arcmin] (formal 1-sigma fit error)
SNR: 12.9660952801952
RA = 5h 37m 12.8s (84.303536 deg.)
Dec = 5d 4' 33" (5.075851 deg.)
Angular difference between Flight and Ground position is 1.852567 arcmin
Partial Coding Fraction: 0.4609375 [ including projection effects ]
Duration
T90: 22.66400000453 +/- 10.2328170104824
Measured from: -12.7719999849796
to: 9.89200001955032 [s; relative to TRIGTIME]
T50: 3.74000000953674 +/- 4.81666771923104
Measured from: 0.232000023126602
to: 3.97200003266335 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 0
to: 1 [s; relative to TRIGTIME]
Total Fluence
Measured from: -13.0999999940395
to: 10.4000000059605 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.400807 0.424474 0.197226 -0.013938
0.037986 0.038344 0.033090 0.028885 [error]
Peak 0.106739 0.163520 0.123272 0.018619
0.009635 0.010331 0.008812 0.006547 [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 1.47e-07 1.88e-07 1.76e-07 2.89e-07 6.07e-07 8.00e-07 erg/cm2
Error 2.19e-08 2.00e-08 3.18e-08 1.02e-07 7.43e-08 1.39e-07 erg/cm2
Peak flux Power-law 1.31e+00 1.24e+00 8.26e-01 8.52e-01 3.72e+00 4.23e+00 ph/cm2/s
Error 1.59e-01 9.66e-02 7.19e-02 1.46e-01 2.80e-01 3.02e-01 ph/cm2/s
Fluence Cutoff-PL 1.31e-07 2.15e-07 1.67e-07 5.68e-08 5.56e-07 5.68e-07 erg/cm2
Error 2.58e-08 2.90e-08 3.94e-08 9.48e-08 7.99e-08 1.19e-07 erg/cm2
Peak flux Cutoff-PL 1.11e+00 1.36e+00 9.01e-01 3.73e-01 3.63e+00 3.75e+00 ph/cm2/s
Error 1.88e-01 1.20e-01 8.78e-02 1.71e-01 2.85e-01 3.28e-01 ph/cm2/s
Fluence Band 1.31e-07 2.14e-07 1.66e-07 8.19e-08 5.58e-07 5.79e-07 erg/cm2
Error 2.53e-08 2.16e-08 3.40e-08 1.09e-07 7.49e-08 1.56e-07 erg/cm2
Peak flux Band 1.11e+00 1.36e+00 8.98e-01 4.43e-01 3.62e+00 3.80e+00 ph/cm2/s
Error 1.91e-01 1.25e-01 1.26e-01 2.33e-01 2.85e-01 3.71e-01 ph/cm2/s
=== Time-averaged spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 2.097 0.197 - - 2.78e-03 3.70e-04 54.696 57
CPL 0.910 1.051 38.5 13.9 1.33e-02 3.13e-02 49.738 56
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.592 0.116 - - 2.90e-02 2.11e-03 68.395 57
CPL 0.685 0.539 73.3 21.5 8.35e-02 5.60e-02 58.289 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: 0.768000 sec.
T50 in the 50-300 keV band: 0.448000 sec.
=== Table of the duration information ==
Value tstart tstop
T100 23.500 -13.100 10.400
T90 22.664 -12.772 9.892
T50 3.740 0.232 3.972
Peak 1.000 0.000 1.000
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
84.3035 +5.0759 0.0147 39.9 -146.3 0.9779 13.0 TRIG_00308812
------------------------------------------
Foreground time interval of the image:
-13.100 9.513 (delta_t = 22.613 [sec])
Background time interval of the image:
-239.288 -13.100 (delta_t = 226.188 [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 -13.100 sec. to 10.400 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.09688 ( -0.190971 0.202744 )
Norm@50keV : 2.782823E-03 ( -3.737956E-04 3.655658E-04) )
------------------------------------------------------------
Chi-Squared = 54.69557 using 59 PHA bins.
Reduced chi-squared = 0.9595714 for 57 degrees of freedom
Null hypothesis probability = 0.562
Photon flux (15-150 keV) in 23.50 sec: 0.437139 ( -0.04673 0.046772 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.07466e-07 ( -7.37454e-08 7.48005e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -13.100 sec. to 10.400 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.909602 ( -1.17026 0.931642 )
Epeak [keV] : 38.4770 ( -17.4049 10.4687 )
Norm@50keV : 1.333256E-02 ( -1.333256E-02 4.922157E-02) )
------------------------------------------------------------
Chi-Squared = 49.73819 using 59 PHA bins.
Reduced chi-squared = 0.8881819 for 56 degrees of freedom
Null hypothesis probability = 0.709
Photon flux (15-150 keV) in 23.50 sec: 0.419642 ( -0.048807 0.048726 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.55914e-07 ( -7.72163e-08 8.26659e-08 ) ergs/cm2
Band function
Time interval is from -13.100 sec. to 10.400 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.26700 ( -0.550480 2.29417 )
beta : -3.83993 ( -6.16007 13.6975 )
Epeak [keV] : 37.7955 ( -13.7072 11.3888 )
Norm@50keV : 8.254215E-03 ( -1.004059E-02 0.201664 )
------------------------------------------------------------
Chi-Squared = 50.11080 using 59 PHA bins.
Reduced chi-squared = 0.9111055 for 55 degrees of freedom
Null hypothesis probability = 0.662
Photon flux (15-150 keV) in 23.50 sec: 0.420305 ( -0.047843 0.046849 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.57911e-07 ( -6.83051e-08 8.15121e-08 ) ergs/cm2
Peak spectrum fit using the pre-slew DRM
Power-law model
Time interval is from 0.000 sec. to 1.000 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.59204 ( -0.115666 0.115635 )
Norm@50keV : 2.903978E-02 ( -2.109818E-03 2.107618E-03) )
------------------------------------------------------------
Chi-Squared = 68.39483 using 59 PHA bins.
Reduced chi-squared = 1.199909 for 57 degrees of freedom
Null hypothesis probability = 0.143
Photon flux (15-150 keV) in 1.000 sec: 3.72241 ( -0.27924 0.27977 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.71847e-07 ( -2.0709e-08 2.0832e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.000 sec. to 1.000 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.684842 ( -0.570980 0.507518 )
Epeak [keV] : 73.3179 ( -12.0943 30.9173 )
Norm@50keV : 8.346461E-02 ( -3.652573E-02 7.551397E-02) )
------------------------------------------------------------
Chi-Squared = 58.28885 using 59 PHA bins.
Reduced chi-squared = 1.040872 for 56 degrees of freedom
Null hypothesis probability = 0.391
Photon flux (15-150 keV) in 1.000 sec: 3.62609 ( -0.28506 0.28558 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.61339e-07 ( -2.1936e-08 2.19e-08 ) ergs/cm2
Band function
Time interval is from 0.000 sec. to 1.000 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.684304 ( -0.508025 0.569874 )
beta : -9.23333 ( -0.766668 5.75657 )
Epeak [keV] : 73.2963 ( -12.0798 30.9511 )
Norm@50keV : 8.351048E-02 ( -3.657466E-02 7.552374E-02) )
------------------------------------------------------------
Chi-Squared = 58.28874 using 59 PHA bins.
Reduced chi-squared = 1.059795 for 55 degrees of freedom
Null hypothesis probability = 0.355
Photon flux (15-150 keV) in 1.000 sec: 3.62250 ( -0.28262 0.2864 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.61207e-07 ( -2.1977e-08 2.185e-08 ) ergs/cm2
Plot creation:
Wed Apr 9 14:44:36 EDT 2008