batgrbproduct Analysis for Trigger=308797
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 12:42:23 EDT 2008
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger308797/GCN5_download_cron
======================================================================
Trigger: 00308797 Segment: 000
BAT Trigger Time: 229382896 [s; MET]
Trigger Stop: 229383216 [s; MET]
UTC: 2008-04-08T21:28:13.296660 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 264.841713908155 Dec: -30.3656230660562 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: NO [ by BAT flight software ]
Image S/N Ratio: 7.83
Image Trigger?: YES
Rate S/N Ratio: 0 [ if not an image trigger ]
Image S/N Ratio: 7.83
Flight Position: [ source = BAT ]
RA: 264.841713908155 Dec: -30.3656230660562 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 264.873522780921 Dec: -30.3003980532069 [deg; J2000]
{ 17h 39m 29.6s , -30d 18' 01.4" }
+/- 3.63312750453367 [arcmin] (estimated 90% radius based on SNR)
+/- 2.36002677387066 [arcmin] (formal 1-sigma fit error)
SNR: 4.81634364482239
RA = 17h 39m 29.6s (264.873523 deg.)
Dec = -30d 18' 1" (-30.300398 deg.)
Angular difference between Flight and Ground position is 4.246053 arcmin
Partial Coding Fraction: 1.03125 [ including projection effects ]
Duration
T90: 320 +/- 0.004
Measured from: 0
to: 320 [s; relative to TRIGTIME]
T50: 320 +/- 0.004
Measured from: 0
to: 320 [s; relative to TRIGTIME]
WARNING: battblocks failed. Used TDRSS fore/background intervals
Fluence
Peak Flux (peak 320 second)
Measured from: 0
to: 320 [s; relative to TRIGTIME]
Total Fluence
Measured from: 0
to: 320 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.637311 0.449114 0.161080 0.098520
0.095742 0.084713 0.070523 0.058842 [error]
Peak 0.637311 0.449114 0.161080 0.098520
0.095742 0.084713 0.070523 0.058842 [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 1.88e-07 1.39e-07 1.64e-07 5.71e-07 6.74e-07 erg/cm2
Error 4.20e-08 4.02e-08 5.68e-08 1.28e-07 1.36e-07 2.12e-07 erg/cm2
Peak flux Power-law 1.86e-02 1.08e-02 3.98e-03 1.94e-03 3.45e-02 3.54e-02 ph/cm2/s
Error 4.42e-03 2.24e-03 1.58e-03 1.84e-03 6.54e-03 6.78e-03 ph/cm2/s
Fluence Cutoff-PL 1.81e-07 2.16e-07 6.87e-08 3.42e-09 4.69e-07 4.69e-07 erg/cm2
Error 4.64e-08 5.44e-08 8.57e-08 1.12e-07 1.49e-07 2.13e-07 erg/cm2
Peak flux Cutoff-PL 1.83e-02 1.26e-02 2.15e-03 5.86e-05 3.31e-02 3.31e-02 ph/cm2/s
Error 4.76e-03 3.05e-03 2.47e-03 1.30e-03 6.61e-03 6.62e-03 ph/cm2/s
Fluence Band 1.83e-07 2.10e-07 8.11e-08 4.11e-08 4.98e-07 5.98e-07 erg/cm2
Error 4.71e-08 4.82e-08 7.08e-08 6.07e-08 1.08e-07 0.00e+00 erg/cm2
Peak flux Band 1.84e-02 1.20e-02 3.28e-03 1.04e-03 3.43e-02 3.48e-02 ph/cm2/s
Error 4.21e-03 2.28e-03 1.75e-03 1.25e-03 6.47e-03 6.87e-03 ph/cm2/s
=== Time-averaged spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 2.442 0.398 - - 1.82e-04 5.51e-05 44.076 57
CPL 1.480 0.000 17.0 21.4 8.37e-04 0.00e+00 42.335 0
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 2.442 0.398 - - 1.82e-04 5.51e-05 44.076 57
CPL 1.480 0.000 17.0 21.4 8.37e-04 0.00e+00 42.335 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 320.000 0.000 320.000
T90 320.000 0.000 320.000
T50 320.000 0.000 320.000
Peak 320.000 0.000 320.000
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
264.8735 -30.3004 0.0393 11.7 -157.3 1.2382 4.8 TRIG_00308797
------------------------------------------
Foreground time interval of the image:
0.000 178.230 (delta_t = 178.230 [sec])
179.000 320.000 (delta_t = 141.000 [sec])
Background time interval of the image:
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
Multiple GTIs in the spectrum
tstart tstop
0.000000 178.230000
179.000000 320.000000
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.44250 ( -0.373857 0.421217 )
Norm@50keV : 1.816250E-04 ( -5.496865E-05 5.529790E-05) )
------------------------------------------------------------
Chi-Squared = 44.07636 using 59 PHA bins.
Reduced chi-squared = 0.7732695 for 57 degrees of freedom
Null hypothesis probability = 0.895
Photon flux (15-150 keV) in 319.2 sec: 3.446100E-02 ( -0.00654058 0.00654151 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.71208e-07 ( -1.31574e-07 1.40011e-07 ) ergs/cm2
Cutoff power-law model
Multiple GTIs in the spectrum
tstart tstop
0.000000 178.230000
179.000000 320.000000
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.47955 ( )
Epeak [keV] : 17.0264 ( -25.0697 17.6361 )
Norm@50keV : 8.374729E-04 ( )
------------------------------------------------------------
Chi-Squared = 42.33462 using 59 PHA bins.
but latest trial 49.9202 gives Chi-Squared = 5.76014
Reduced chi-squared = 0.7559753 for 56 degrees of freedom
Null hypothesis probability = 0.911
Photon flux (15-150 keV) in 319.2 sec: 3.308998E-02 ( -0.00661972 0.00660459 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.6893e-07 ( -1.2678e-07 1.72049e-07 ) ergs/cm2
Band function
Multiple GTIs in the spectrum
tstart tstop
0.000000 178.230000
179.000000 320.000000
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.36417 ( -8.63583 6.36417 )
beta : -3.83212 ( -6.16788 1.63714 )
Epeak [keV] : 19.7710 ( -19.6710 24.8076 )
Norm@50keV : 9.371351E-04 ( -2.65333 33.9445 )
------------------------------------------------------------
Chi-Squared = 42.25825 using 59 PHA bins.
Reduced chi-squared = 0.7683318 for 55 degrees of freedom
Null hypothesis probability = 0.896
Photon flux (15-150 keV) in 319.2 sec: 3.433717E-02 ( -0.00640991 0.0065359 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.97891e-07 ( -1.20364e-07 9.4879e-08 ) ergs/cm2
Peak spectrum fit using the pre-slew DRM
Power-law model
Time interval is from 179.000 sec. to 320.000 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.44250 ( -0.373857 0.421217 )
Norm@50keV : 1.816250E-04 ( -5.496865E-05 5.529790E-05) )
------------------------------------------------------------
Chi-Squared = 44.07636 using 59 PHA bins.
Reduced chi-squared = 0.7732695 for 57 degrees of freedom
Null hypothesis probability = 0.895
Photon flux (15-150 keV) in 319.2 sec: 3.446100E-02 ( -0.00654058 0.00654151 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.71208e-07 ( -1.31574e-07 1.40011e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from 179.000 sec. to 320.000 sec.
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.47955 ( )
Epeak [keV] : 17.0264 ( -25.0697 17.6361 )
Norm@50keV : 8.374729E-04 ( )
------------------------------------------------------------
Chi-Squared = 42.33462 using 59 PHA bins.
but latest trial 49.9202 gives Chi-Squared = 5.76014
Reduced chi-squared = 0.7559753 for 56 degrees of freedom
Null hypothesis probability = 0.911
Photon flux (15-150 keV) in 319.2 sec: 3.308998E-02 ( -0.00661972 0.00660459 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.6893e-07 ( -1.2678e-07 1.72049e-07 ) ergs/cm2
Band function
Time interval is from 179.000 sec. to 320.000 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.36417 ( -8.63583 6.36417 )
beta : -3.83212 ( -6.16788 1.63714 )
Epeak [keV] : 19.7710 ( -19.6710 24.8076 )
Norm@50keV : 9.371351E-04 ( -2.65333 33.9445 )
------------------------------------------------------------
Chi-Squared = 42.25825 using 59 PHA bins.
Reduced chi-squared = 0.7683318 for 55 degrees of freedom
Null hypothesis probability = 0.896
Photon flux (15-150 keV) in 319.2 sec: 3.433717E-02 ( -0.00640991 0.0065359 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.97891e-07 ( -1.20364e-07 9.4879e-08 ) ergs/cm2
Plot creation:
Wed Apr 9 13:27:08 EDT 2008