batgrbproduct Analysis for Trigger=273855
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): Thu Dec 13 16:52:31 EST 2007
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger273855/GCN5_download_cron
======================================================================
Trigger: 00273855 Segment: 000
BAT Trigger Time: 197345536 [s; MET]
Trigger Stop: 197345856 [s; MET]
UTC: 2007-04-04T02:12:14.132660 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 245.146800066778 Dec: -51.5792085803031 [deg; J2000]
Catalogged Source?: YES
Point Source?: YES
GRB Indicated?: NO [ by BAT flight software ]
Image S/N Ratio: 5.86
Image Trigger?: YES
Rate S/N Ratio: 0 [ if not an image trigger ]
Image S/N Ratio: 5.86
Flight Position: [ source = BAT ]
RA: 245.146800066778 Dec: -51.5792085803031 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 245.534753256309 Dec: -51.5976202866011 [deg; J2000]
{ 16h 22m 08.3s , -51d 35' 51.4" }
+/- 5.80808261432332 [arcmin] (estimated 90% radius based on SNR)
+/- 3.95208005323435 [arcmin] (formal 1-sigma fit error)
SNR: 2.46401287412206
RA = 16h 22m 8.3s (245.534753 deg.)
Dec = -51d 35' 51" (-51.597620 deg.)
Angular difference between Flight and Ground position is 14.504377 arcmin
Partial Coding Fraction: 0.984375 [ including projection effects ]
Duration
T90: 320 +/-
Measured from: 0
to: 320 [s; relative to TRIGTIME]
T50: 320 +/-
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 0.139361 0.055462 0.016383 -0.025209
0.041800 0.038095 0.032851 0.030407 [error]
Peak 0.139361 0.055462 0.016383 -0.025209
0.041800 0.038095 0.032851 0.030407 [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 3.33e-08 2.78e-08 1.58e-08 1.33e-08 8.28e-08 9.05e-08 erg/cm2
Error 1.79e-08 1.88e-08 2.17e-08 4.54e-08 5.57e-08 8.18e-08 erg/cm2
Peak flux Power-law 3.34e-02 1.56e-02 4.44e-03 1.58e-03 5.44e-02 5.50e-02 ph/cm2/s
Error 1.83e-02 1.02e-02 5.89e-03 4.77e-03 2.77e-02 2.83e-02 ph/cm2/s
Fluence Cutoff-PL 3.75e-08 3.07e-08 1.52e-09 5.46e-13 6.97e-08 7.00e-08 erg/cm2
Error 1.97e-08 2.21e-08 1.56e-08 1.76e-08 3.47e-08 3.47e-08 erg/cm2
Peak flux Cutoff-PL 3.66e-02 1.82e-02 5.05e-04 9.48e-08 5.53e-02 5.53e-02 ph/cm2/s
Error 1.96e-02 1.21e-02 4.29e-03 2.09e-03 2.56e-02 2.56e-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 2.65e-02 2.80e-02 5.66e-02 0.00e+00 0.00e+00 0.00e+00 ph/cm2/s
Error 3.05e-02 0.00e+00 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 2.817 1.348 - - 2.25e-04 2.36e-04 46.755 57
CPL -2.462 0.000 22.4 15.7 1.87e+00 7.52e+00 45.049 56
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 2.817 1.348 - - 2.25e-04 2.36e-04 46.755 57
CPL -2.462 0.000 22.4 15.7 1.87e+00 7.52e+00 45.049 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 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
245.5348 -51.5976 0.0778 17.2 172.1 0.1943 2.5 TRIG_00273855
------------------------------------------
Foreground time interval of the image:
0.000 33.056 (delta_t = 33.056 [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 33.056 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.81683 ( -1.06665 1.62847 )
Norm@50keV : 2.251448E-04 ( -2.251448E-04 2.477106E-04) )
------------------------------------------------------------
Chi-Squared = 46.75485 using 59 PHA bins.
Reduced chi-squared = 0.8202606 for 57 degrees of freedom
Null hypothesis probability = 0.832
Photon flux (15-150 keV) in 33.06 sec: 5.438356E-02 ( -0.0275192 0.0278796 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.27786e-08 ( -4.88382e-08 6.26487e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.000 sec. to 33.056 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -2.46199 ( )
Epeak [keV] : 22.3622 ( -22.1451 9.30170 )
Norm@50keV : 1.86645 ( -2.26799 12.7748 )
------------------------------------------------------------
Chi-Squared = 45.04901 using 59 PHA bins.
Reduced chi-squared = 0.8044466 for 56 degrees of freedom
Null hypothesis probability = 0.852
Photon flux (15-150 keV) in 33.06 sec: 5.527629E-02 ( -0.0255745 0.0255803 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.96954e-08 ( -3.36914e-08 3.56995e-08 ) ergs/cm2
Band function
Time interval is from 0.000 sec. to 33.056 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.40376 ( -10.2862 4.71376 )
beta : -3.37346 ( -4.36163 3.63378 )
Epeak [keV] : 15.0986 ( -17.6470 9982.25 )
Norm@50keV : 1.823298E-03 ( -45.4584 197.860 )
------------------------------------------------------------
Chi-Squared = 46.43012 using 59 PHA bins.
Reduced chi-squared = 0.8441840 for 55 degrees of freedom
Null hypothesis probability = 0.788
Photon flux (15-150 keV) in 33.06 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 33.056 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.81683 ( -1.06665 1.62847 )
Norm@50keV : 2.251448E-04 ( -2.251448E-04 2.477106E-04) )
------------------------------------------------------------
Chi-Squared = 46.75485 using 59 PHA bins.
Reduced chi-squared = 0.8202606 for 57 degrees of freedom
Null hypothesis probability = 0.832
Photon flux (15-150 keV) in 33.06 sec: 5.438356E-02 ( -0.0275192 0.0278796 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.27786e-08 ( -4.88382e-08 6.26487e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.000 sec. to 33.056 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -2.46199 ( )
Epeak [keV] : 22.3622 ( -22.1451 9.30170 )
Norm@50keV : 1.86645 ( -2.26799 12.7748 )
------------------------------------------------------------
Chi-Squared = 45.04901 using 59 PHA bins.
Reduced chi-squared = 0.8044466 for 56 degrees of freedom
Null hypothesis probability = 0.852
Photon flux (15-150 keV) in 33.06 sec: 5.527629E-02 ( -0.0255745 0.0255803 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.96954e-08 ( -3.36914e-08 3.56995e-08 ) ergs/cm2
Band function
Time interval is from 0.000 sec. to 33.056 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.40376 ( -10.2862 4.71376 )
beta : -3.37346 ( -4.36163 3.63378 )
Epeak [keV] : 15.0986 ( -17.6470 9982.25 )
Norm@50keV : 1.823298E-03 ( -45.4584 197.860 )
------------------------------------------------------------
Chi-Squared = 46.43012 using 59 PHA bins.
Reduced chi-squared = 0.8441840 for 55 degrees of freedom
Null hypothesis probability = 0.788
Photon flux (15-150 keV) in 33.06 sec: ( ) ph/cm2/s
Energy fluence (15-150 keV) : 0 ( 0 0 ) ergs/cm2
Plot creation:
Thu Dec 13 16:57:39 EST 2007