batgrbproduct Analysis for Trigger=291218
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 12:23:16 EST 2007
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger291218/GCN5_download_cron
======================================================================
Trigger: 00291218 Segment: 000
BAT Trigger Time: 211650858.752 [s; MET]
Trigger Stop: 211650859.776 [s; MET]
UTC: 2007-09-16T15:54:16.523780 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 272.697943894705 Dec: -26.1728405791281 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 8.09
Image Trigger?: NO
Rate S/N Ratio: 10.9087121146357 [ if not an image trigger ]
Image S/N Ratio: 8.09
Flight Position: [ source = BAT ]
RA: 272.697943894705 Dec: -26.1728405791281 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 272.873855489986 Dec: -26.164952590799 [deg; J2000]
{ 18h 11m 29.7s , -26d 09' 53.8" }
+/- 5.16872547099273 [arcmin] (estimated 90% radius based on SNR)
+/- 3.47795606715108 [arcmin] (formal 1-sigma fit error)
SNR: 2.91071137433377
RA = 18h 11m 29.7s (272.873855 deg.)
Dec = -26d 9' 54" (-26.164953 deg.)
Angular difference between Flight and Ground position is 9.484632 arcmin
Partial Coding Fraction: 1 [ including projection effects ]
Duration
T90: 413.824000030756 +/- 477.814266194096
Measured from: 0.375999987125397
to: 414.200000017881 [s; relative to TRIGTIME]
T50: 168.768000036478 +/- 408.071638583234
Measured from: 156.535999983549
to: 325.304000020027 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 331.683999985456
to: 332.683999985456 [s; relative to TRIGTIME]
Total Fluence
Measured from: -1.03200000524521
to: 415.416000008583 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.271112 0.202930 -0.174447 0.036983
0.326131 0.334124 0.316475 0.325597 [error]
Peak 0.037282 0.005645 0.058165 0.044238
0.022265 0.021536 0.022744 0.024001 [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 8.13e-08 5.70e-08 2.65e-08 1.70e-08 1.74e-07 1.70e-07 erg/cm2
Error 1.07e-07 1.05e-07 1.44e-07 5.08e-06 3.91e-07 5.26e-06 erg/cm2
Peak flux Power-law 1.55e-01 1.90e-01 1.69e-01 2.59e-01 6.04e-01 7.73e-01 ph/cm2/s
Error 2.44e-01 1.80e-01 1.69e-01 6.26e-01 5.20e-01 8.63e-01 ph/cm2/s
Fluence Cutoff-PL 9.75e-08 7.06e-08 2.82e-09 6.52e-13 1.73e-07 1.72e-07 erg/cm2
Error 1.24e-07 1.40e-07 1.50e-07 1.53e-08 3.34e-07 5.35e-06 erg/cm2
Peak flux Cutoff-PL 1.55e-01 1.90e-01 1.69e-01 2.58e-01 6.03e-01 7.71e-01 ph/cm2/s
Error 2.44e-01 1.86e-01 1.69e-01 6.40e-01 5.20e-01 8.60e-01 ph/cm2/s
Fluence Band 9.39e-08 5.28e-08 1.68e-08 6.17e-09 1.67e-07 0.00e+00 erg/cm2
Error 1.23e-07 9.66e-08 5.04e-06 0.00e+00 0.00e+00 0.00e+00 erg/cm2
Peak flux Band 9.48e-02 9.83e-02 2.72e-01 1.24e-01 4.90e-01 6.96e-01 ph/cm2/s
Error 2.53e-01 4.43e-01 4.34e-01 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 3.088 6.500 - - 3.38e-05 9.73e-05 47.495 57
CPL -0.607 0.000 18.9 5000.0 1.90e-02 8.04e-01 47.278 0
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.170 3.692 - - 5.16e-03 4.78e-03 57.878 57
CPL 0.581 0.000 165.3 0.0 8.46e-03 0.00e+00 57.811 56
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 416.448 -1.032 415.416
T90 413.824 0.376 414.200
T50 168.768 156.536 325.304
Peak 1.000 331.684 332.684
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
272.8739 -26.1650 0.0660 15.1 -25.8 0.4758 2.9 TRIG_00291218
------------------------------------------
Foreground time interval of the image:
-1.032 160.049 (delta_t = 161.081 [sec])
Background time interval of the image:
-239.752 -1.032 (delta_t = 238.720 [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 -1.032 sec. to 415.416 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 3.08794 ( -6.08794 6.91206 )
Norm@50keV : 3.383112E-05 ( -3.383112E-05 1.608302E-04) )
------------------------------------------------------------
Chi-Squared = 47.49523 using 59 PHA bins.
Reduced chi-squared = 0.8332497 for 57 degrees of freedom
Null hypothesis probability = 0.811
Photon flux (15-150 keV) in 416.4 sec: 9.878514E-03 ( -0.00987851 0.0177924 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.74335e-07 ( -1.74335e-07 6.07082e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -1.032 sec. to 415.416 sec.
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.606791 ( )
Epeak [keV] : 18.8789 ( -20.0987 9979.89 )
Norm@50keV : 1.896695E-02 ( -5.501606E-02 1.55269 )
------------------------------------------------------------
Chi-Squared = 47.27781 using 59 PHA bins.
but latest trial 1.39649 gives Chi-Squared = 5.66481
Reduced chi-squared = 0.8442465 for 56 degrees of freedom
Null hypothesis probability = 0.790
Photon flux (15-150 keV) in 416.4 sec: 1.101019E-02 ( -0.0110102 0.0162194 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.72543e-07 ( -1.72543e-07 4.96311e-07 ) ergs/cm2
Band function
Time interval is from -1.032 sec. to 415.416 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.73658 ( -8.26342 6.73658 )
beta : -9.36741 ( -0.632591 19.3674 )
Epeak [keV] : 5.11757 ( -5.01757 9994.88 )
Norm@50keV : 3.637763E-04 ( -3.637763E-04 267826. )
------------------------------------------------------------
Chi-Squared = 47.38987 using 59 PHA bins.
Reduced chi-squared = 0.8616339 for 55 degrees of freedom
Null hypothesis probability = 0.757
Photon flux (15-150 keV) in 416.4 sec: 1.023560E-02 ( -0.0102356 0.0174066 ) 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 331.704 sec. to 332.664 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.16971 ( -4.16971 3.21364 )
Norm@50keV : 5.162412E-03 ( -5.162412E-03 4.394502E-03) )
------------------------------------------------------------
Chi-Squared = 57.87791 using 59 PHA bins.
Reduced chi-squared = 1.015402 for 57 degrees of freedom
Null hypothesis probability = 0.443
Photon flux (15-150 keV) in 0.9600 sec: 0.603507 ( -0.515257 0.524843 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.07796e-08 ( -4.57507e-08 5.19875e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 331.704 sec. to 332.664 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.581055 ( )
Epeak [keV] : 165.312 ( )
Norm@50keV : 8.457731E-03 ( )
------------------------------------------------------------
Chi-Squared = 57.81130 using 59 PHA bins.
Reduced chi-squared = 1.032345 for 56 degrees of freedom
Null hypothesis probability = 0.408
Photon flux (15-150 keV) in 0.9600 sec: 0.603296 ( -0.515209 0.524644 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.45944e-08 ( -5.45944e-08 2.63795e-08 ) ergs/cm2
Band function
Time interval is from 331.704 sec. to 332.664 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.127644 ( -15.0000 0.00000 )
beta : -9.24750 ( -0.628331 19.3717 )
Epeak [keV] : 134.362 ( -37.9192 9905.65 )
Norm@50keV : 1.150954E-02 ( -0.219705 3.20221 )
------------------------------------------------------------
Chi-Squared = 57.77933 using 59 PHA bins.
Reduced chi-squared = 1.050533 for 55 degrees of freedom
Null hypothesis probability = 0.373
Photon flux (15-150 keV) in 0.9600 sec: 0.490471 ( -0.490471 0.377145 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.80213e-08 ( -4.99386e-08 4.80875e-08 ) ergs/cm2
Plot creation:
Fri Dec 14 13:01:24 EST 2007