batgrbproduct Analysis for Trigger=311159
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 7 04:26:53 EDT 2008
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger311159/GCN5_download_cron
======================================================================
Trigger: 00311159 Segment: 000
BAT Trigger Time: 231788784 [s; MET]
Trigger Stop: 231788848 [s; MET]
UTC: 2008-05-06T17:46:21.229360 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 329.434621981101 Dec: 39.002344120271 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 7.18
Image Trigger?: YES
Rate S/N Ratio: 0 [ if not an image trigger ]
Image S/N Ratio: 7.18
Flight Position: [ source = BAT ]
RA: 329.434621981101 Dec: 39.002344120271 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 329.466889012691 Dec: 38.9611140662285 [deg; J2000]
{ 21h 57m 52.1s , +38d 57' 40.0" }
+/- 2.53525564178275 [arcmin] (estimated 90% radius based on SNR)
+/- 1.75964491438809 [arcmin] (formal 1-sigma fit error)
SNR: 8.05275414818448
RA = 21h 57m 52.1s (329.466889 deg.)
Dec = 38d 57' 40" (38.961114 deg.)
Angular difference between Flight and Ground position is 2.895619 arcmin
Partial Coding Fraction: 0.609375 [ including projection effects ]
Duration
T90: 150.176000028849 +/- 10.0777854600822
Measured from: 33.6119999885559
to: 183.788000017405 [s; relative to TRIGTIME]
T50: 101.159999996424 +/- 55.6496299940482
Measured from: 60.0200000107288
to: 161.180000007153 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 134.476000010967
to: 135.476000010967 [s; relative to TRIGTIME]
Total Fluence
Measured from: 25.8280000090599
to: 188.796000003815 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.733492 0.868650 0.492548 0.226400
0.072733 0.073343 0.066421 0.061320 [error]
Peak 0.012036 0.017449 0.005770 0.010316
0.004954 0.005045 0.004637 0.004221 [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 2.61e-07 3.82e-07 4.18e-07 8.56e-07 1.32e-06 1.92e-06 erg/cm2
Error 4.13e-08 3.78e-08 6.72e-08 2.87e-07 1.52e-07 3.48e-07 erg/cm2
Peak flux Power-law 1.50e-01 1.25e-01 7.13e-02 6.02e-02 3.73e-01 4.06e-01 ph/cm2/s
Error 8.12e-02 4.41e-02 3.89e-02 7.61e-02 1.31e-01 1.44e-01 ph/cm2/s
Fluence Cutoff-PL 2.61e-07 3.83e-07 4.18e-07 8.50e-07 1.32e-06 1.91e-06 erg/cm2
Error 4.13e-08 3.78e-08 6.69e-08 2.85e-07 1.52e-07 3.46e-07 erg/cm2
Peak flux Cutoff-PL 1.49e-01 1.25e-01 7.13e-02 5.98e-02 3.72e-01 4.06e-01 ph/cm2/s
Error 8.12e-02 4.41e-02 3.89e-02 7.56e-02 1.31e-01 1.44e-01 ph/cm2/s
Fluence Band 2.61e-07 3.81e-07 4.12e-07 8.34e-07 1.31e-06 1.95e-06 erg/cm2
Error 2.57e-08 3.75e-08 4.84e-08 2.00e-07 1.43e-07 1.92e-07 erg/cm2
Peak flux Band 1.47e-01 1.27e-01 7.09e-02 5.83e-02 3.72e-01 4.03e-01 ph/cm2/s
Error 5.46e-02 5.57e-02 5.58e-02 5.32e-02 1.31e-01 1.52e-01 ph/cm2/s
=== Time-averaged spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.872 0.195 - - 8.83e-04 1.02e-04 47.159 57
CPL 1.795 0.000 127.1 0.0 9.70e-04 5.21e-04 47.384 56
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.812 0.722 - - 2.69e-03 1.13e-03 39.931 57
CPL 1.827 0.000 9886.9 0.0 2.68e-03 3.07e-01 39.933 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: 148.480000 sec.
T50 in the 50-300 keV band: 79.104000 sec.
=== Table of the duration information ==
Value tstart tstop
T100 162.968 25.828 188.796
T90 150.176 33.612 183.788
T50 101.160 60.020 161.180
Peak 1.000 134.476 135.476
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
329.4669 +38.9611 0.0237 37.5 -19.4 0.7522 8.1 TRIG_00311159
------------------------------------------
Foreground time interval of the image:
25.828 72.301 (delta_t = 46.473 [sec])
Background time interval of the image:
-134.799 25.828 (delta_t = 160.627 [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 25.828 sec. to 188.796 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.87170 ( -0.191349 0.198253 )
Norm@50keV : 8.829434E-04 ( -1.028287E-04 1.003661E-04) )
------------------------------------------------------------
Chi-Squared = 47.15920 using 59 PHA bins.
Reduced chi-squared = 0.8273544 for 57 degrees of freedom
Null hypothesis probability = 0.821
Photon flux (15-150 keV) in 163.0 sec: 0.125216 ( -0.012607 0.012632 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.32313e-06 ( -1.51432e-07 1.5351e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from 25.828 sec. to 188.796 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.79455 ( )
Epeak [keV] : 127.069 ( )
Norm@50keV : 9.695257E-04 ( -1.175917E-04 9.246962E-04) )
------------------------------------------------------------
Chi-Squared = 47.38449 using 59 PHA bins.
Reduced chi-squared = 0.8461517 for 56 degrees of freedom
Null hypothesis probability = 0.787
Photon flux (15-150 keV) in 163.0 sec: 0.125169 ( -0.012603 0.012627 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.32325e-06 ( -1.51606e-07 1.53388e-07 ) ergs/cm2
Band function
Time interval is from 25.828 sec. to 188.796 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.42026 ( -8.57974 6.42026 )
beta : -1.87119 ( -0.205234 0.190653 )
Epeak [keV] : 18.4182 ( -18.3182 330.417 )
Norm@50keV : 2.435761E-03 ( -2.435761E-03 1.52632 )
------------------------------------------------------------
Chi-Squared = 47.15982 using 59 PHA bins.
Reduced chi-squared = 0.8574513 for 55 degrees of freedom
Null hypothesis probability = 0.765
Photon flux (15-150 keV) in 163.0 sec: 0.125256 ( -0.012497 0.012358 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.31472e-06 ( -1.29499e-07 1.57481e-07 ) ergs/cm2
Peak spectrum fit using the pre-slew DRM
Power-law model
Time interval is from 134.476 sec. to 135.476 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.81209 ( -0.668691 0.774808 )
Norm@50keV : 2.691033E-03 ( -1.186659E-03 1.078287E-03) )
------------------------------------------------------------
Chi-Squared = 39.93102 using 59 PHA bins.
Reduced chi-squared = 0.7005442 for 57 degrees of freedom
Null hypothesis probability = 0.958
Photon flux (15-150 keV) in 1.000 sec: 0.372573 ( -0.131093 0.131239 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.47722e-08 ( -1.0162e-08 1.07157e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 134.476 sec. to 135.476 sec.
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.82733 ( )
Epeak [keV] : 9886.93 ( )
Norm@50keV : 2.679408E-03 ( -1.221426E-03 0.613593 )
------------------------------------------------------------
Chi-Squared = 39.93286 using 59 PHA bins.
but latest trial 1.11765 gives Chi-Squared = 0.398331
Reduced chi-squared = 0.7130868 for 56 degrees of freedom
Null hypothesis probability = 0.948
Photon flux (15-150 keV) in 1.000 sec: 0.372452 ( -0.131053 0.131198 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.47551e-08 ( -1.01562e-08 1.07427e-08 ) ergs/cm2
Band function
Time interval is from 134.476 sec. to 135.476 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.28333 ( -8.71667 6.28333 )
beta : -1.86354 ( -8.13646 0.720239 )
Epeak [keV] : 41.2929 ( -41.1929 9958.71 )
Norm@50keV : 6.118696E-03 ( -6.118697E-03 8.628553E-02) )
------------------------------------------------------------
Chi-Squared = 39.93154 using 59 PHA bins.
Reduced chi-squared = 0.7260280 for 55 degrees of freedom
Null hypothesis probability = 0.937
Photon flux (15-150 keV) in 1.000 sec: 0.371793 ( -0.130847 0.131072 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.46962e-08 ( -8.98e-09 8.6405e-09 ) ergs/cm2
Plot creation:
Wed May 7 04:59:44 EDT 2008