batgrbproduct Analysis for Trigger=280846
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 00:40:17 EST 2007
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger280846/GCN5_download_cron
======================================================================
Trigger: 00280846 Segment: 000
BAT Trigger Time: 202203857.472 [s; MET]
Trigger Stop: 202203859.52 [s; MET]
UTC: 2007-05-30T07:44:15.483520 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 278.828202487554 Dec: -32.9721123274726 [deg; J2000]
Catalogged Source?: YES
Point Source?: YES
GRB Indicated?: NO [ by BAT flight software ]
Image S/N Ratio: 6.72
Image Trigger?: NO
Rate S/N Ratio: 6.40312423743285 [ if not an image trigger ]
Image S/N Ratio: 6.72
Flight Position: [ source = BAT ]
RA: 278.828202487554 Dec: -32.9721123274726 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 278.759707163301 Dec: -32.8965800049498 [deg; J2000]
{ 18h 35m 02.3s , -32d 53' 47.7" }
+/- 5.03927314299544 [arcmin] (estimated 90% radius based on SNR)
+/- 3.17775692376743 [arcmin] (formal 1-sigma fit error)
SNR: 3.01811418934002
RA = 18h 35m 2.3s (278.759707 deg.)
Dec = -32d 53' 48" (-32.896580 deg.)
Angular difference between Flight and Ground position is 5.695251 arcmin
Partial Coding Fraction: 0.984375 [ including projection effects ]
Duration
T90: 2.04800000786781 +/-
Measured from: 0
to: 2.04800000786781 [s; relative to TRIGTIME]
T50: 2.04800000786781 +/-
Measured from: 0
to: 2.04800000786781 [s; relative to TRIGTIME]
WARNING: battblocks failed. Used TDRSS fore/background intervals
Fluence
Peak Flux (peak 2.04800000786781 second)
Measured from: -1.49011611938477e-08
to: 2.04799999296665 [s; relative to TRIGTIME]
Total Fluence
Measured from: 0
to: 2.04800000786781 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.053958 0.001369 0.002002 0.004494
0.008415 0.007013 0.006100 0.005391 [error]
Peak 0.053958 0.001369 0.002002 0.004494
0.008415 0.007013 0.006100 0.005391 [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 1.31e-08 4.09e-09 7.02e-10 1.39e-10 1.80e-08 1.80e-08 erg/cm2
Error 3.87e-09 2.88e-09 1.16e-09 5.40e-10 6.87e-09 7.00e-09 erg/cm2
Peak flux Power-law 2.20e-01 3.94e-02 3.39e-03 3.14e-04 2.63e-01 2.64e-01 ph/cm2/s
Error 6.46e-02 2.65e-02 5.68e-03 1.12e-03 8.36e-02 8.37e-02 ph/cm2/s
Fluence Cutoff-PL 1.54e-08 2.36e-09 3.41e-12 8.83e-19 1.78e-08 1.77e-08 erg/cm2
Error 4.28e-09 2.53e-09 1.81e-10 6.77e-12 5.46e-09 5.42e-09 erg/cm2
Peak flux Cutoff-PL 2.20e-01 3.94e-02 3.38e-03 3.12e-04 2.63e-01 2.63e-01 ph/cm2/s
Error 6.45e-02 2.65e-02 5.67e-03 1.11e-03 8.36e-02 8.37e-02 ph/cm2/s
Fluence Band 1.29e-08 1.62e-08 0.00e+00 0.00e+00 0.00e+00 0.00e+00 erg/cm2
Error 7.37e-09 0.00e+00 0.00e+00 0.00e+00 0.00e+00 0.00e+00 erg/cm2
Peak flux Band 2.20e-01 3.94e-02 3.28e-03 2.37e-05 2.76e-01 2.63e-01 ph/cm2/s
Error 6.46e-02 2.65e-02 1.77e-03 8.00e-02 8.37e-02 0.00e+00 ph/cm2/s
=== Time-averaged spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 4.334 1.195 - - 3.24e-04 3.57e-04 59.120 57
CPL -2.500 0.000 13.0 3.3 2.16e+02 5.56e+02 55.688 0
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 4.334 1.195 - - 3.24e-04 3.57e-04 59.120 57
CPL -2.500 0.000 13.0 3.3 2.16e+02 5.56e+02 55.688 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 2.048 0.000 2.048
T90 2.048 0.000 2.048
T50 2.048 0.000 2.048
Peak 2.048 -0.000 2.048
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
278.7597 -32.8966 0.0637 11.2 -57.3 0.0704 3.0 TRIG_00280846
------------------------------------------
Foreground time interval of the image:
0.000 2.048 (delta_t = 2.048 [sec])
Background time interval of the image:
-10.472 -9.472 (delta_t = 1.000 [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 0.000 sec. to 2.048 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 4.33426 ( -0.820246 1.56995 )
Norm@50keV : 3.238425E-04 ( -3.238425E-04 3.901400E-04) )
------------------------------------------------------------
Chi-Squared = 59.11988 using 59 PHA bins.
Reduced chi-squared = 1.037191 for 57 degrees of freedom
Null hypothesis probability = 0.398
Photon flux (15-150 keV) in 2.048 sec: 0.263407 ( -0.082932 0.084273 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.80167e-08 ( -6.42189e-09 7.31458e-09 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.000 sec. to 2.048 sec.
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -2.49976 ( )
Epeak [keV] : 13.0155 ( -3.40897 3.14336 )
Norm@50keV : 215.795 ( -238.527 872.810 )
------------------------------------------------------------
Chi-Squared = 55.68795 using 59 PHA bins.
but latest trial 9.60269 gives Chi-Squared = 0.734039
Reduced chi-squared = 0.9944277 for 56 degrees of freedom
Null hypothesis probability = 0.487
Photon flux (15-150 keV) in 2.048 sec: 0.263211 ( -0.082908 0.084244 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.77733e-08 ( -5.3668e-09 5.55751e-09 ) ergs/cm2
Band function
Time interval is from 0.000 sec. to 2.048 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -9.18962 ( -0.647211 1.41637 )
beta : -4.53987 ( -1.49823 4.47656 )
Epeak [keV] : 509.386 ( -7.62535 3.04448 )
Norm@50keV : 3.574057E-02 ( -365.263 39852.0 )
------------------------------------------------------------
Chi-Squared = 59.02264 using 59 PHA bins.
Reduced chi-squared = 1.073139 for 55 degrees of freedom
Null hypothesis probability = 0.331
Photon flux (15-150 keV) in 2.048 sec: 0.276062 ( -0.079549 0.080522 ) 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 2.048 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 4.33426 ( -0.820246 1.56995 )
Norm@50keV : 3.238425E-04 ( -3.238425E-04 3.901400E-04) )
------------------------------------------------------------
Chi-Squared = 59.11988 using 59 PHA bins.
Reduced chi-squared = 1.037191 for 57 degrees of freedom
Null hypothesis probability = 0.398
Photon flux (15-150 keV) in 2.048 sec: 0.263407 ( -0.082932 0.084273 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.80167e-08 ( -6.42189e-09 7.31458e-09 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.000 sec. to 2.048 sec.
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -2.49976 ( )
Epeak [keV] : 13.0155 ( -3.40897 3.14336 )
Norm@50keV : 215.795 ( -238.527 872.810 )
------------------------------------------------------------
Chi-Squared = 55.68795 using 59 PHA bins.
but latest trial 9.60269 gives Chi-Squared = 0.734039
Reduced chi-squared = 0.9944277 for 56 degrees of freedom
Null hypothesis probability = 0.487
Photon flux (15-150 keV) in 2.048 sec: 0.263211 ( -0.082908 0.084244 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.77733e-08 ( -5.3668e-09 5.55751e-09 ) ergs/cm2
Band function
Time interval is from 0.000 sec. to 2.048 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -9.18962 ( -0.647211 1.41637 )
beta : -4.53987 ( -1.49823 4.47656 )
Epeak [keV] : 509.386 ( -7.62535 3.04448 )
Norm@50keV : 3.574057E-02 ( -365.263 39852.0 )
------------------------------------------------------------
Chi-Squared = 59.02264 using 59 PHA bins.
Reduced chi-squared = 1.073139 for 55 degrees of freedom
Null hypothesis probability = 0.331
Photon flux (15-150 keV) in 2.048 sec: 0.276062 ( -0.079549 0.080522 ) ph/cm2/s
Energy fluence (15-150 keV) : 0 ( 0 0 ) ergs/cm2
Plot creation:
Fri Dec 14 00:46:31 EST 2007