batgrbproduct Analysis for Trigger=147827
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): Tue Jan 8 09:55:07 EST 2008
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger147827/GCN5_download_cron
======================================================================
Trigger: 00147827 Segment: 000
BAT Trigger Time: 144076752 [s; MET]
Trigger Stop: 144076816 [s; MET]
UTC: 2005-07-26T13:19:12.358340 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 257.078961032826 Dec: -22.655317727832 [deg; J2000]
Catalogged Source?: YES
Point Source?: YES
GRB Indicated?: NO [ by BAT flight software ]
Image S/N Ratio: 33282
Image Trigger?: YES
Rate S/N Ratio: 0 [ if not an image trigger ]
Image S/N Ratio: 33282
Flight Position: [ source = BAT ]
RA: 257.078961032826 Dec: -22.655317727832 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 257.099167153164 Dec: -22.5370605056666 [deg; J2000]
{ 17h 08m 23.8s , -22d 32' 13.4" }
+/- 4.02145832525917 [arcmin] (estimated 90% radius based on SNR)
+/- 1.9253765656006 [arcmin] (formal 1-sigma fit error)
SNR: 4.16594254959366
RA = 17h 8m 23.8s (257.099167 deg.)
Dec = -22d 32' 13" (-22.537061 deg.)
Angular difference between Flight and Ground position is 7.183175 arcmin
Partial Coding Fraction: 0.953125 [ including projection effects ]
Duration
T90: 64 +/-
Measured from: 0
to: 64 [s; relative to TRIGTIME]
T50: 64 +/-
Measured from: 0
to: 64 [s; relative to TRIGTIME]
WARNING: battblocks failed. Used TDRSS fore/background intervals
Fluence
Peak Flux (peak 64 second)
Measured from: 0
to: 64 [s; relative to TRIGTIME]
Total Fluence
Measured from: 0
to: 64 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.188143 0.085523 0.016552 -0.031432
0.035318 0.027700 0.022753 0.019467 [error]
Peak 0.188143 0.085523 0.016552 -0.031432
0.035318 0.027700 0.022753 0.019467 [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 4.98e-08 3.74e-08 1.87e-08 1.34e-08 1.12e-07 1.19e-07 erg/cm2
Error 1.62e-08 1.48e-08 1.56e-08 2.44e-08 4.02e-08 5.19e-08 erg/cm2
Peak flux Power-law 5.02e-02 2.12e-02 5.30e-03 1.62e-03 7.76e-02 7.83e-02 ph/cm2/s
Error 1.67e-02 7.99e-03 5.18e-03 2.74e-03 2.18e-02 2.21e-02 ph/cm2/s
Fluence Cutoff-PL 4.97e-08 3.75e-08 1.86e-08 1.23e-08 1.12e-07 1.17e-07 erg/cm2
Error 1.62e-08 1.59e-08 1.87e-08 2.42e-08 4.24e-08 5.47e-08 erg/cm2
Peak flux Cutoff-PL 5.02e-02 2.12e-02 5.29e-03 1.61e-03 7.76e-02 7.82e-02 ph/cm2/s
Error 1.67e-02 7.99e-03 5.18e-03 2.72e-03 2.18e-02 2.21e-02 ph/cm2/s
Fluence Band 5.22e-08 3.67e-08 1.49e-08 7.59e-09 1.07e-07 1.84e-07 erg/cm2
Error 1.67e-08 1.52e-08 8.96e-09 3.04e-08 0.00e+00 0.00e+00 erg/cm2
Peak flux Band 5.02e-02 2.12e-02 5.29e-03 1.61e-03 7.76e-02 7.81e-02 ph/cm2/s
Error 1.67e-02 8.66e-03 5.18e-03 2.72e-03 2.19e-02 2.22e-02 ph/cm2/s
=== Time-averaged spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 2.999 0.796 - - 2.82e-04 2.34e-04 45.874 57
CPL 1.968 0.478 0.9 12.3 1.53e-03 2.23e-03 46.249 0
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 2.999 0.796 - - 2.82e-04 2.34e-04 45.874 57
CPL 1.968 0.477 0.9 12.3 1.53e-03 2.23e-03 46.249 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 64.000 0.000 64.000
T90 64.000 0.000 64.000
T50 64.000 0.000 64.000
Peak 64.000 0.000 64.000
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
257.0992 -22.5371 0.0461 11.1 60.4 0.2611 4.2 TRIG_00147827
------------------------------------------
Foreground time interval of the image:
0.000 33.040 (delta_t = 33.040 [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
Time interval is from 0.000 sec. to 33.040 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.99948 ( -0.695467 0.897342 )
Norm@50keV : 2.824434E-04 ( -2.824434E-04 1.860052E-04) )
------------------------------------------------------------
Chi-Squared = 45.87437 using 59 PHA bins.
Reduced chi-squared = 0.8048135 for 57 degrees of freedom
Null hypothesis probability = 0.854
Photon flux (15-150 keV) in 33.04 sec: 7.762660E-02 ( -0.0217966 0.0218072 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.12072e-07 ( -3.79065e-08 4.24382e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.000 sec. to 33.040 sec.
Parameters : value lower 90% higher 90%
Photon index: 1.96823 ( -0.876957 7.844102E-02) )
Epeak [keV] : 0.878266 ( -0.746225 23.8478 )
Norm@50keV : 1.531111E-03 ( -1.531111E-03 2.922105E-03) )
------------------------------------------------------------
Chi-Squared = 46.24876 using 59 PHA bins.
but latest trial 1.09444 gives Chi-Squared = 0.529850
but latest trial -4.13060 gives Chi-Squared = 1.39296
Reduced chi-squared = 0.8258706 for 56 degrees of freedom
Null hypothesis probability = 0.820
Photon flux (15-150 keV) in 33.04 sec: 7.759244E-02 ( -0.0217874 0.0217983 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.11811e-07 ( -4.20583e-08 4.26867e-08 ) ergs/cm2
Band function
Time interval is from 0.000 sec. to 33.040 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.85840 ( -7.30649 7.69351 )
beta : -8.76560 ( -0.896281 0.695446 )
Epeak [keV] : 5.61391 ( -5.51391 9994.39 )
Norm@50keV : 1.227265E-03 ( -3.837861E-02 2.529522E-02) )
------------------------------------------------------------
Chi-Squared = 46.80291 using 59 PHA bins.
Reduced chi-squared = 0.8509620 for 55 degrees of freedom
Null hypothesis probability = 0.776
Photon flux (15-150 keV) in 33.04 sec: 7.759203E-02 ( -0.0220035 0.0217432 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.06618e-07 ( -3.06892e-08 3.01259e-08 ) ergs/cm2
Peak spectrum fit using the pre-slew DRM
Power-law model
Time interval is from 0.000 sec. to 33.040 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.99948 ( -0.695467 0.897342 )
Norm@50keV : 2.824434E-04 ( -2.824434E-04 1.860052E-04) )
------------------------------------------------------------
Chi-Squared = 45.87437 using 59 PHA bins.
Reduced chi-squared = 0.8048135 for 57 degrees of freedom
Null hypothesis probability = 0.854
Photon flux (15-150 keV) in 33.04 sec: 7.762660E-02 ( -0.0217966 0.0218072 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.12072e-07 ( -3.79065e-08 4.24382e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.000 sec. to 33.040 sec.
Parameters : value lower 90% higher 90%
Photon index: 1.96823 ( -0.876957 7.727206E-02) )
Epeak [keV] : 0.878266 ( -0.746225 23.8478 )
Norm@50keV : 1.531111E-03 ( -1.531111E-03 2.922105E-03) )
------------------------------------------------------------
Chi-Squared = 46.24876 using 59 PHA bins.
but latest trial 1.09444 gives Chi-Squared = 0.529850
but latest trial -4.13060 gives Chi-Squared = 1.39296
Reduced chi-squared = 0.8258706 for 56 degrees of freedom
Null hypothesis probability = 0.820
Photon flux (15-150 keV) in 33.04 sec: 7.759244E-02 ( -0.0217874 0.0217983 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.11811e-07 ( -4.20583e-08 4.26867e-08 ) ergs/cm2
Band function
Time interval is from 0.000 sec. to 33.040 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.85840 ( -7.30649 7.69351 )
beta : -8.76560 ( -0.896281 0.695446 )
Epeak [keV] : 5.61391 ( -5.51391 9994.39 )
Norm@50keV : 1.227265E-03 ( -3.837861E-02 2.529522E-02) )
------------------------------------------------------------
Chi-Squared = 46.80291 using 59 PHA bins.
Reduced chi-squared = 0.8509620 for 55 degrees of freedom
Null hypothesis probability = 0.776
Photon flux (15-150 keV) in 33.04 sec: 7.759203E-02 ( -0.0220035 0.0217432 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.06618e-07 ( -3.06892e-08 3.01259e-08 ) ergs/cm2
Plot creation:
Tue Jan 8 10:00:24 EST 2008