batgrbproduct Analysis for Trigger=285466
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): Fri Dec 14 04:35:24 EST 2007
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger285466/GCN5_download_cron
======================================================================
Trigger: 00285466 Segment: 000
BAT Trigger Time: 206524128 [s; MET]
Trigger Stop: 206524744 [s; MET]
UTC: 2007-07-19T07:48:45.902940 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 257.281742736444 Dec: -36.4076604819208 [deg; J2000]
Catalogged Source?: YES
Point Source?: YES
GRB Indicated?: NO [ by BAT flight software ]
Image S/N Ratio: 7.02
Image Trigger?: YES
Rate S/N Ratio: 0 [ if not an image trigger ]
Image S/N Ratio: 7.02
Flight Position: [ source = BAT ]
RA: 257.281742736444 Dec: -36.4076604819208 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 257.168890772416 Dec: -36.3909066868102 [deg; J2000]
{ 17h 08m 40.5s , -36d 23' 27.3" }
+/- 6.10247068551838 [arcmin] (estimated 90% radius based on SNR)
+/- 4.73985191785864 [arcmin] (formal 1-sigma fit error)
SNR: 2.29597617591697
RA = 17h 8m 40.5s (257.168891 deg.)
Dec = -36d 23' 27" (-36.390907 deg.)
Angular difference between Flight and Ground position is 5.542009 arcmin
Partial Coding Fraction: 0.75 [ including projection effects ]
Duration
T90: 616 +/-
Measured from: 0
to: 616 [s; relative to TRIGTIME]
T50: 616 +/-
Measured from: 0
to: 616 [s; relative to TRIGTIME]
WARNING: battblocks failed. Used TDRSS fore/background intervals
Fluence
Peak Flux (peak 616 second)
Measured from: 0
to: 616 [s; relative to TRIGTIME]
Total Fluence
Measured from: 0
to: 616 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.130408 0.025106 0.014823 0.004582
0.034844 0.030406 0.026450 0.023471 [error]
Peak 0.130408 0.025106 0.014823 0.004582
0.034844 0.030406 0.026450 0.023471 [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 3.40e-08 1.91e-08 6.74e-09 3.12e-09 6.15e-08 6.28e-08 erg/cm2
Error 1.56e-08 1.52e-08 1.26e-08 1.67e-08 3.86e-08 4.64e-08 erg/cm2
Peak flux Power-law 3.46e-02 1.10e-02 1.95e-03 4.00e-04 4.78e-02 4.79e-02 ph/cm2/s
Error 1.62e-02 8.37e-03 3.49e-03 1.87e-03 2.26e-02 2.28e-02 ph/cm2/s
Fluence Cutoff-PL 3.87e-08 1.50e-08 1.71e-10 2.98e-15 5.40e-08 5.40e-08 erg/cm2
Error 1.74e-08 1.71e-08 9.97e-09 2.75e-09 2.60e-08 3.74e-08 erg/cm2
Peak flux Cutoff-PL 3.88e-02 9.27e-03 5.54e-05 4.61e-10 4.82e-02 4.82e-02 ph/cm2/s
Error 1.77e-02 1.00e-02 2.78e-03 4.32e-04 2.10e-02 2.10e-02 ph/cm2/s
Fluence Band 0.00e+00 0.00e+00 0.00e+00 0.00e+00 0.00e+00 0.00e+00 erg/cm2
Error 0.00e+00 0.00e+00 0.00e+00 0.00e+00 0.00e+00 0.00e+00 erg/cm2
Peak flux Band 3.42e-02 1.16e-02 4.85e-02 0.00e+00 0.00e+00 0.00e+00 ph/cm2/s
Error 1.61e-02 2.39e-02 0.00e+00 0.00e+00 0.00e+00 0.00e+00 ph/cm2/s
=== Time-averaged spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 3.340 1.600 - - 1.36e-04 1.59e-04 46.243 57
CPL 0.138 0.000 12.6 16.9 5.76e-02 0.00e+00 45.438 0
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 3.340 1.600 - - 1.36e-04 1.59e-04 46.243 57
CPL 0.138 0.000 12.6 16.9 5.76e-02 0.00e+00 45.438 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 616.000 0.000 616.000
T90 616.000 0.000 616.000
T50 616.000 0.000 616.000
Peak 616.000 0.000 616.000
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
257.1689 -36.3909 0.0840 18.9 63.8 0.1496 2.3 TRIG_00285466
------------------------------------------
Foreground time interval of the image:
0.000 33.037 (delta_t = 33.037 [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 33.038 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 3.33964 ( -1.08161 2.11806 )
Norm@50keV : 1.363187E-04 ( -1.363187E-04 1.816364E-04) )
------------------------------------------------------------
Chi-Squared = 46.24257 using 59 PHA bins.
Reduced chi-squared = 0.8112732 for 57 degrees of freedom
Null hypothesis probability = 0.845
Photon flux (15-150 keV) in 33.04 sec: 4.781393E-02 ( -0.0223639 0.0227839 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.14709e-08 ( -3.3228e-08 4.39733e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.000 sec. to 33.038 sec.
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.137540 ( )
Epeak [keV] : 12.5825 ( -12.8302 20.8724 )
Norm@50keV : 5.759191E-02 ( )
------------------------------------------------------------
Chi-Squared = 45.43755 using 59 PHA bins.
but latest trial 44.7396 gives Chi-Squared = 4.72187
Reduced chi-squared = 0.8113848 for 56 degrees of freedom
Null hypothesis probability = 0.842
Photon flux (15-150 keV) in 33.04 sec: 4.817942E-02 ( -0.0209725 0.020989 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.3985e-08 ( -2.48868e-08 2.71536e-08 ) ergs/cm2
Band function
Time interval is from 0.000 sec. to 33.038 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.65607 ( -1.86969 13.1303 )
beta : -2.69725 ( -1.93808 1.23556 )
Epeak [keV] : 7.01217 ( -6.91217 9992.99 )
Norm@50keV : 1.717158E-03 ( -1.606085E-02 2.691663E-02) )
------------------------------------------------------------
Chi-Squared = 47.48684 using 59 PHA bins.
Reduced chi-squared = 0.8633971 for 55 degrees of freedom
Null hypothesis probability = 0.754
Photon flux (15-150 keV) in 33.04 sec: ( ) ph/cm2/s
Energy fluence (15-150 keV) : 0 ( 0 0 ) ergs/cm2
Peak spectrum fit using the pre-slew DRM
Power-law model
Time interval is from 0.000 sec. to 33.038 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 3.33964 ( -1.08161 2.11806 )
Norm@50keV : 1.363187E-04 ( -1.363187E-04 1.816364E-04) )
------------------------------------------------------------
Chi-Squared = 46.24257 using 59 PHA bins.
Reduced chi-squared = 0.8112732 for 57 degrees of freedom
Null hypothesis probability = 0.845
Photon flux (15-150 keV) in 33.04 sec: 4.781393E-02 ( -0.0223639 0.0227839 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.14709e-08 ( -3.3228e-08 4.39733e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.000 sec. to 33.038 sec.
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.137540 ( )
Epeak [keV] : 12.5825 ( -12.8302 20.8724 )
Norm@50keV : 5.759191E-02 ( )
------------------------------------------------------------
Chi-Squared = 45.43755 using 59 PHA bins.
but latest trial 44.7396 gives Chi-Squared = 4.72187
Reduced chi-squared = 0.8113848 for 56 degrees of freedom
Null hypothesis probability = 0.842
Photon flux (15-150 keV) in 33.04 sec: 4.817942E-02 ( -0.0209725 0.020989 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.3985e-08 ( -2.48868e-08 2.71536e-08 ) ergs/cm2
Band function
Time interval is from 0.000 sec. to 33.038 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.65607 ( -1.86969 13.1303 )
beta : -2.69725 ( -1.93808 1.23556 )
Epeak [keV] : 7.01217 ( -6.91217 9992.99 )
Norm@50keV : 1.717158E-03 ( -1.606085E-02 2.691663E-02) )
------------------------------------------------------------
Chi-Squared = 47.48684 using 59 PHA bins.
Reduced chi-squared = 0.8633971 for 55 degrees of freedom
Null hypothesis probability = 0.754
Photon flux (15-150 keV) in 33.04 sec: ( ) ph/cm2/s
Energy fluence (15-150 keV) : 0 ( 0 0 ) ergs/cm2
Plot creation:
Fri Dec 14 04:39:05 EST 2007