batgrbproduct Analysis for Trigger=158261
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 Jan 9 14:34:11 EST 2008
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger158261/SDC
======================================================================
Trigger: 00158261 Segment: 000
BAT Trigger Time: 150116504 [s; MET]
Trigger Stop: 150116568 [s; MET]
UTC: 2005-10-04T11:01:44.235940 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 244.443493711151 Dec: -15.3465557326457 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 14.18
Image Trigger?: YES
Rate S/N Ratio: 0 [ if not an image trigger ]
Image S/N Ratio: 14.18
Flight Position: [ source = BAT ]
RA: 244.443493711151 Dec: -15.3465557326457 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 244.471836053379 Dec: -15.3456089354623 [deg; J2000]
{ 16h 17m 53.2s , -15d 20' 44.2" }
+/- 1.54707375962514 [arcmin] (estimated 90% radius based on SNR)
+/- 0.986522838607451 [arcmin] (formal 1-sigma fit error)
SNR: 16.3075362063898
RA = 16h 17m 53.2s (244.471836 deg.)
Dec = -15d 20' 44" (-15.345609 deg.)
Angular difference between Flight and Ground position is 1.640891 arcmin
Partial Coding Fraction: 0.5234375 [ including projection effects ]
Duration
T90: 44.7039999961853 +/- 9.41176497807657
Measured from: -1.47999998927116
to: 43.2240000069141 [s; relative to TRIGTIME]
T50: 22.3240000009537 +/- 4.2728898830851
Measured from: 15.0760000050068
to: 37.4000000059605 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 29.0839999914169
to: 30.0839999914169 [s; relative to TRIGTIME]
Total Fluence
Measured from: -6.99599999189377
to: 52.6159999966621 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 1.578197 0.198106 -0.015501 -0.007879
0.062245 0.053932 0.045130 0.039022 [error]
Peak 0.068163 0.004821 -0.005564 0.006284
0.008153 0.007037 0.005939 0.005040 [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 5.67e-07 9.74e-08 7.96e-09 6.98e-10 6.73e-07 6.73e-07 erg/cm2
Error 7.07e-08 2.69e-08 5.25e-09 8.25e-10 7.89e-08 7.89e-08 erg/cm2
Peak flux Power-law 7.63e-01 8.65e-02 4.14e-03 2.07e-04 8.54e-01 8.54e-01 ph/cm2/s
Error 1.74e-01 5.80e-02 7.33e-03 7.86e-04 2.06e-01 2.06e-01 ph/cm2/s
Fluence Cutoff-PL 5.67e-07 9.74e-08 7.93e-09 6.93e-10 6.73e-07 6.73e-07 erg/cm2
Error 7.06e-08 2.69e-08 5.24e-09 8.18e-10 7.88e-08 7.89e-08 erg/cm2
Peak flux Cutoff-PL 7.62e-01 8.64e-02 4.13e-03 2.05e-04 8.53e-01 8.53e-01 ph/cm2/s
Error 1.74e-01 5.80e-02 7.31e-03 7.80e-04 2.06e-01 2.06e-01 ph/cm2/s
Fluence Band 5.58e-07 9.66e-08 7.90e-09 9.41e-11 6.54e-07 6.65e-07 erg/cm2
Error 6.93e-08 2.67e-08 7.65e-08 7.81e-08 0.00e+00 0.00e+00 erg/cm2
Peak flux Band 7.85e-01 7.55e-02 7.42e-04 2.27e-06 8.60e-01 8.53e-01 ph/cm2/s
Error 1.78e-01 6.85e-02 2.98e-03 5.20e-04 2.02e-01 2.06e-01 ph/cm2/s
=== Time-averaged spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 5.498 0.555 - - 1.46e-04 7.13e-05 48.697 57
CPL 1.742 1.885 1.4 3.7 2.18e-01 4.19e+02 47.320 0
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 5.091 1.281 - - 5.16e-04 5.61e-04 56.303 57
CPL 1.642 3.435 2.0 5.6 4.57e-01 8.02e+02 55.764 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 59.612 -6.996 52.616
T90 44.704 -1.480 43.224
T50 22.324 15.076 37.400
Peak 1.000 29.084 30.084
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
244.4718 -15.3456 0.0117 33.2 -48.3 1.8721 16.3 TRIG_00158261
------------------------------------------
Foreground time interval of the image:
-6.996 52.616 (delta_t = 59.612 [sec])
Background time interval of the image:
-299.000 -6.996 (delta_t = 292.004 [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 -6.996 sec. to 52.616 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 5.49804 ( -0.420196 0.688950 )
Norm@50keV : 1.463952E-04 ( -7.243703E-05 7.014415E-05) )
------------------------------------------------------------
Chi-Squared = 48.69691 using 59 PHA bins.
Reduced chi-squared = 0.8543318 for 57 degrees of freedom
Null hypothesis probability = 0.775
Photon flux (15-150 keV) in 59.61 sec: 0.368102 ( -0.043903 0.043935 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.72937e-07 ( -7.88426e-08 7.88998e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -6.996 sec. to 52.616 sec.
Parameters : value lower 90% higher 90%
Photon index: 1.74218 ( -0.993008 2.77707 )
Epeak [keV] : 1.36571 ( -0.888808 6.46830 )
Norm@50keV : 0.217589 ( -0.125984 838.353 )
------------------------------------------------------------
Chi-Squared = 47.32039 using 59 PHA bins.
but latest trial 0.228348 gives Chi-Squared = 1.088333E-02
but latest trial 7.83401 gives Chi-Squared = 0.372036
Reduced chi-squared = 0.8450070 for 56 degrees of freedom
Null hypothesis probability = 0.789
Photon flux (15-150 keV) in 59.61 sec: 0.366222 ( -0.045038 0.044829 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.72615e-07 ( -7.88473e-08 7.88223e-08 ) ergs/cm2
Band function
Time interval is from -6.996 sec. to 52.616 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -9.05670 ( -0.943295 7.71289 )
beta : -5.61600 ( -0.557324 0.525788 )
Epeak [keV] : 146.637 ( -146.537 9853.36 )
Norm@50keV : 1.782084E-02 ( -7.623540E-03 1.128535E-02) )
------------------------------------------------------------
Chi-Squared = 48.56587 using 59 PHA bins.
Reduced chi-squared = 0.8830159 for 55 degrees of freedom
Null hypothesis probability = 0.717
Photon flux (15-150 keV) in 59.61 sec: 0.366591 ( -0.04601 0.042762 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.53713e-07 ( -7.51718e-08 7.7791e-08 ) ergs/cm2
Peak spectrum fit using the pre-slew DRM
Power-law model
Time interval is from 29.084 sec. to 30.084 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 5.09093 ( -0.787412 1.77485 )
Norm@50keV : 5.157458E-04 ( -5.157458E-04 6.060675E-04) )
------------------------------------------------------------
Chi-Squared = 56.30316 using 59 PHA bins.
Reduced chi-squared = 0.9877748 for 57 degrees of freedom
Null hypothesis probability = 0.501
Photon flux (15-150 keV) in 1.000 sec: 0.853928 ( -0.205948 0.206242 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.65618e-08 ( -7.1741e-09 7.5882e-09 ) ergs/cm2
Cutoff power-law model
Time interval is from 29.084 sec. to 30.084 sec.
Parameters : value lower 90% higher 90%
Photon index: 1.64224 ( -1.40147 5.46867 )
Epeak [keV] : 2.01674 ( -2.00674 9.14109 )
Norm@50keV : 0.457462 ( -0.457462 1603.70 )
------------------------------------------------------------
Chi-Squared = 55.76426 using 59 PHA bins.
but latest trial 0.240770 gives Chi-Squared = 23.4502
but latest trial 1.82858 gives Chi-Squared = 0.00000
Reduced chi-squared = 0.9957904 for 56 degrees of freedom
Null hypothesis probability = 0.484
Photon flux (15-150 keV) in 1.000 sec: 0.853076 ( -0.205883 0.206174 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.65573e-08 ( -7.1843e-09 7.5858e-09 ) ergs/cm2
Band function
Time interval is from 29.084 sec. to 30.084 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -8.36420 ( -1.63580 2.79259 )
beta : -5.38657 ( -1.42419 1.05212 )
Epeak [keV] : 316.641 ( -316.541 9683.36 )
Norm@50keV : 5.179013E-02 ( -5.179013E-02 9.644864E-02) )
------------------------------------------------------------
Chi-Squared = 56.12565 using 59 PHA bins.
Reduced chi-squared = 1.020466 for 55 degrees of freedom
Null hypothesis probability = 0.432
Photon flux (15-150 keV) in 1.000 sec: 0.860199 ( -0.201145 0.202511 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.64573e-08 ( -7.2021e-09 6.1302e-09 ) ergs/cm2
Plot creation:
Wed Jan 9 15:09:06 EST 2008