batgrbproduct Analysis for Trigger=325827
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 Sep 25 02:22:54 EDT 2008
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger325827/GCN5_download_cron
======================================================================
Trigger: 00325827 Segment: 000
BAT Trigger Time: 243980067.328 [s; MET]
Trigger Stop: 243980067.84 [s; MET]
UTC: 2008-09-24T20:14:24.204500 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 272.140237836602 Dec: -37.0151707107451 [deg; J2000]
Catalogged Source?: YES
Point Source?: YES
GRB Indicated?: NO [ by BAT flight software ]
Image S/N Ratio: 9.32
Image Trigger?: NO
Rate S/N Ratio: 15.0332963783729 [ if not an image trigger ]
Image S/N Ratio: 9.32
Flight Position: [ source = BAT ]
RA: 272.140237836602 Dec: -37.0151707107451 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 272.110208332205 Dec: -36.9737592329997 [deg; J2000]
{ 18h 08m 26.4s , -36d 58' 25.5" }
+/- 1.29953214745963 [arcmin] (estimated 90% radius based on SNR)
+/- 0.482635135039953 [arcmin] (formal 1-sigma fit error)
SNR: 20.9201832143059
Angular difference between Flight and Ground position is 2.871337 arcmin
Partial Coding Fraction: 0.796875 [ including projection effects ]
Duration
T90: 7.74400001764297 +/- 0.603367237293625
Measured from: 0.0480000674724579
to: 7.79200008511543 [s; relative to TRIGTIME]
T50: 4.62800002098083 +/- 1.2237189127495
Measured from: 1.62800008058548
to: 6.25600010156631 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 5.45999997854233
to: 6.45999997854233 [s; relative to TRIGTIME]
Total Fluence
Measured from: -0.216000020503998
to: 8.2960000038147 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.543404 0.067344 0.017191 0.005697
0.020507 0.017025 0.014384 0.012246 [error]
Peak 0.098538 0.011749 0.003860 0.005631
0.007346 0.005994 0.004878 0.004193 [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 1.81e-07 3.31e-08 2.92e-09 2.79e-10 2.17e-07 2.17e-07 erg/cm2
Error 2.08e-08 8.59e-09 1.83e-09 3.61e-10 2.32e-08 2.32e-08 erg/cm2
Peak flux Power-law 1.05e+00 1.44e-01 8.88e-03 5.79e-04 1.20e+00 1.20e+00 ph/cm2/s
Error 1.70e-01 5.90e-02 8.75e-03 1.14e-03 1.92e-01 1.92e-01 ph/cm2/s
Fluence Cutoff-PL 1.86e-07 2.19e-08 7.02e-11 6.34e-16 2.09e-07 2.13e-07 erg/cm2
Error 2.29e-08 1.42e-08 2.40e-09 2.95e-10 2.37e-08 3.33e-08 erg/cm2
Peak flux Cutoff-PL 1.04e+00 1.44e-01 8.85e-03 5.74e-04 1.20e+00 1.20e+00 ph/cm2/s
Error 1.70e-01 5.89e-02 8.73e-03 1.13e-03 1.92e-01 1.92e-01 ph/cm2/s
Fluence Band 1.78e-07 3.28e-08 2.90e-09 2.76e-10 2.15e-07 2.15e-07 erg/cm2
Error 2.04e-08 8.55e-09 1.82e-09 3.58e-10 1.90e-08 2.30e-08 erg/cm2
Peak flux Band 1.04e+00 1.44e-01 8.85e-03 5.74e-04 1.20e+00 1.20e+00 ph/cm2/s
Error 1.75e-01 5.89e-02 8.99e-03 1.13e-03 1.92e-01 1.92e-01 ph/cm2/s
=== Time-averaged spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 5.504 0.516 - - 3.29e-04 1.65e-04 46.393 57
CPL 1.498 0.000 2.5 6.1 7.54e-01 1.55e+03 45.701 0
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 5.022 0.778 - - 7.61e-04 7.61e-04 63.896 57
CPL 1.833 1.599 1.0 5.4 4.17e-01 0.00e+00 64.350 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 8.512 -0.216 8.296
T90 7.744 0.048 7.792
T50 4.628 1.628 6.256
Peak 1.000 5.460 6.460
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
272.1102 -36.9738 0.0092 32.2 -159.7 0.6888 20.9 TRIG_00325827
------------------------------------------
Foreground time interval of the image:
-0.216 8.296 (delta_t = 8.512 [sec])
Background time interval of the image:
-239.328 -0.216 (delta_t = 239.112 [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.
- 4) For short bursts (T90<1sec), the specrtum is also fit with Blackbody, OTTB, and Double Blackbody.
Time averaged spectrum fit using the pre-slew DRM
Power-law model
Time interval is from -0.216 sec. to 8.296 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 5.50352 ( -0.502838 0.529283 )
Norm@50keV : 3.290978E-04 ( -1.342957E-04 1.955888E-04) )
------------------------------------------------------------
Chi-Squared = 46.39313 using 59 PHA bins.
Reduced chi-squared = 0.8139146 for 57 degrees of freedom
Null hypothesis probability = 0.841
Photon flux (15-150 keV) in 8.512 sec: 0.827046 ( -0.090037 0.090129 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.17362e-07 ( -2.31654e-08 2.32182e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.216 sec. to 8.296 sec.
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.49808 ( )
Epeak [keV] : 2.52172 ( -4.72662 7.56830 )
Norm@50keV : 0.753827 ( -2.30262 3093.95 )
------------------------------------------------------------
Chi-Squared = 45.70064 using 59 PHA bins.
but latest trial 2873.09 gives Chi-Squared = 45.5183
Reduced chi-squared = 0.8160828 for 56 degrees of freedom
Null hypothesis probability = 0.836
Photon flux (15-150 keV) in 8.512 sec: 0.826166 ( -0.089912 0.090004 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.08636e-07 ( -2.36966e-08 2.36404e-08 ) ergs/cm2
Band function
Time interval is from -0.216 sec. to 8.296 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -8.72122 ( -1.27878 2.54270 )
beta : -5.50351 ( -0.529940 0.503800 )
Epeak [keV] : 189.344 ( -189.244 9810.66 )
Norm@50keV : 4.473019E-02 ( -1.825355E-02 2.658270E-02) )
------------------------------------------------------------
Chi-Squared = 46.39313 using 59 PHA bins.
Reduced chi-squared = 0.8435115 for 55 degrees of freedom
Null hypothesis probability = 0.789
Photon flux (15-150 keV) in 8.512 sec: 0.822908 ( -0.089173 0.094912 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.14906e-07 ( -1.50722e-08 2.29381e-08 ) ergs/cm2
Peak spectrum fit using the pre-slew DRM
Power-law model
Time interval is from 5.460 sec. to 6.460 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 5.02182 ( -0.723925 0.831827 )
Norm@50keV : 7.610174E-04 ( -7.610174E-04 7.618236E-04) )
------------------------------------------------------------
Chi-Squared = 63.89568 using 59 PHA bins.
Reduced chi-squared = 1.120977 for 57 degrees of freedom
Null hypothesis probability = 0.247
Photon flux (15-150 keV) in 1.000 sec: 1.19899 ( -0.19208 0.19218 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.83204e-08 ( -6.7889e-09 7.0058e-09 ) ergs/cm2
Cutoff power-law model
Time interval is from 5.460 sec. to 6.460 sec.
Photon index: 1.83346 ( -0.738181 2.46069 )
Epeak [keV] : 1.00474 ( -0.296944 10.4857 )
Norm@50keV : 0.416567 ( )
------------------------------------------------------------
Chi-Squared = 64.34988 using 59 PHA bins.
but latest trial 1.09528 gives Chi-Squared = 1.505280E-02
but latest trial 0.491832 gives Chi-Squared = 0.00000
but latest trial 11.4904 gives Chi-Squared = 0.00000
Reduced chi-squared = 1.149105 for 56 degrees of freedom
Null hypothesis probability = 0.207
Photon flux (15-150 keV) in 1.000 sec: 1.19790 ( -0.19195 0.19204 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.82986e-08 ( -6.7767e-09 7.021e-09 ) ergs/cm2
Band function
Time interval is from 5.460 sec. to 6.460 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.65413 ( -7.58785 0.379010 )
beta : -8.76465 ( -0.831649 0.724468 )
Epeak [keV] : 8.61293 ( -8.51293 9991.39 )
Norm@50keV : 2.629349E-02 ( -22.9858 264.192 )
------------------------------------------------------------
Chi-Squared = 96.12817 using 59 PHA bins.
Reduced chi-squared = 1.747785 for 55 degrees of freedom
Null hypothesis probability = 5.041E-04
Photon flux (15-150 keV) in 1.000 sec: 1.19790 ( -0.19195 0.19204 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.88964e-08 ( -7.15e-09 6.2118e-09 ) ergs/cm2
Plot creation:
Thu Sep 25 02:47:21 EDT 2008