batgrbproduct Analysis for Trigger=280958
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 00:47:40 EST 2007
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger280958/SDC
======================================================================
Trigger: 00280958 Segment: 000
BAT Trigger Time: 202270219.52 [s; MET]
Trigger Stop: 202270223.616 [s; MET]
UTC: 2007-05-31T02:10:17.529860 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 6.67853589686105 Dec: 74.3038706234283 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 10.24
Image Trigger?: NO
Rate S/N Ratio: 14.0712472794703 [ if not an image trigger ]
Image S/N Ratio: 10.24
Flight Position: [ source = BAT ]
RA: 6.67853589686105 Dec: 74.3038706234283 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 6.70236885399593 Dec: 74.313355046058 [deg; J2000]
{ 00h 26m 48.6s , +74d 18' 48.1" }
+/- 1.7408271321957 [arcmin] (estimated 90% radius based on SNR)
+/- 0.753581685765298 [arcmin] (formal 1-sigma fit error)
SNR: 13.7778591778342
RA = 0h 26m 48.6s (6.702369 deg.)
Dec = 74d 18' 48" (74.313355 deg.)
Angular difference between Flight and Ground position is 0.688046 arcmin
Partial Coding Fraction: 0.4414062 [ including projection effects ]
Duration
T90: 44.4920000135899 +/- 5.95717553211001
Measured from: -1.04800000786781
to: 43.444000005722 [s; relative to TRIGTIME]
T50: 21.3840000033379 +/- 5.85877802671562
Measured from: 2.47999998927116
to: 23.863999992609 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 1.0799999833107
to: 2.0799999833107 [s; relative to TRIGTIME]
Total Fluence
Measured from: -2.41200000047684
to: 46.3400000035763 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.345901 0.576073 0.492851 0.195185
0.056176 0.057834 0.053590 0.051934 [error]
Peak 0.023955 0.034230 0.050280 0.022217
0.007990 0.008603 0.008284 0.007697 [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 1.30e-07 2.53e-07 3.83e-07 1.25e-06 1.08e-06 2.01e-06 erg/cm2
Error 2.70e-08 3.12e-08 5.13e-08 3.78e-07 1.27e-07 4.09e-07 erg/cm2
Peak flux Power-law 2.16e-01 2.98e-01 3.04e-01 5.66e-01 1.00e-00 1.38e+00 ph/cm2/s
Error 1.03e-01 8.64e-02 6.21e-02 2.62e-01 2.21e-01 2.89e-01 ph/cm2/s
Fluence Cutoff-PL 1.26e-07 2.56e-07 3.89e-07 1.05e-06 1.07e-06 1.70e-06 erg/cm2
Error 3.17e-08 3.49e-08 6.05e-08 6.80e-07 1.28e-07 5.79e-07 erg/cm2
Peak flux Cutoff-PL 0.00e+00 0.00e+00 0.00e+00 0.00e+00 0.00e+00 0.00e+00 ph/cm2/s
Error 0.00e+00 0.00e+00 0.00e+00 0.00e+00 0.00e+00 0.00e+00 ph/cm2/s
Fluence Band 1.82e-06 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 1.39e+00 0.00e+00 0.00e+00 0.00e+00 0.00e+00 0.00e+00 ph/cm2/s
Error 0.00e+00 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 1.405 0.197 - - 2.29e-03 2.49e-04 54.571 57
CPL 1.200 0.572 214.9 4957.4 2.83e-03 2.08e-03 54.508 56
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 0.971 0.380 - - 8.70e-03 1.89e-03 50.049 57
CPL 0.754 0.000 363.2 0.0 1.07e-02 0.00e+00 50.054 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: 45.632000 sec.
T50 in the 50-300 keV band: 25.664000 sec.
=== Table of the duration information ==
Value tstart tstop
T100 48.752 -2.412 46.340
T90 44.492 -1.048 43.444
T50 21.384 2.480 23.864
Peak 1.000 1.080 2.080
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
6.7024 +74.3134 0.0139 44.2 -175.5 1.6680 13.8 TRIG_00280958
------------------------------------------
Foreground time interval of the image:
-2.412 44.285 (delta_t = 46.697 [sec])
Background time interval of the image:
-239.520 -2.412 (delta_t = 237.108 [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 -2.412 sec. to 46.340 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.40451 ( -0.197153 0.196535 )
Norm@50keV : 2.285414E-03 ( -2.490715E-04 2.489134E-04) )
------------------------------------------------------------
Chi-Squared = 54.57090 using 59 PHA bins.
Reduced chi-squared = 0.9573842 for 57 degrees of freedom
Null hypothesis probability = 0.567
Photon flux (15-150 keV) in 48.75 sec: 0.278610 ( -0.032153 0.032328 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.07552e-06 ( -1.26321e-07 1.27233e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -2.412 sec. to 46.340 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.20027 ( -0.747791 0.396437 )
Epeak [keV] : 214.946 ( -129.822 9785.05 )
Norm@50keV : 2.833765E-03 ( -7.874202E-04 3.369662E-03) )
------------------------------------------------------------
Chi-Squared = 54.50805 using 59 PHA bins.
Reduced chi-squared = 0.9733581 for 56 degrees of freedom
Null hypothesis probability = 0.532
Photon flux (15-150 keV) in 48.75 sec: 0.276996 ( -0.033269 0.033162 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.07033e-06 ( -1.28983e-07 1.27701e-07 ) ergs/cm2
Band function
Time interval is from -2.412 sec. to 46.340 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.03826 ( -8.84174 4.97678 )
beta : -1.40948 ( -8.03768 0.751768 )
Epeak [keV] : 62.2906 ( -248.156 9751.74 )
Norm@50keV : 4.345518E-03 ( -6.910339E-04 67325.5 )
------------------------------------------------------------
Chi-Squared = 54.60537 using 59 PHA bins.
Reduced chi-squared = 0.9928249 for 55 degrees of freedom
Null hypothesis probability = 0.490
Photon flux (15-150 keV) in 48.75 sec: 0.276998 ( -0.033276 0.016638 ) 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 1.080 sec. to 2.080 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.971038 ( -0.397798 0.362636 )
Norm@50keV : 8.695384E-03 ( -1.925189E-03 1.848275E-03) )
------------------------------------------------------------
Chi-Squared = 50.04871 using 59 PHA bins.
Reduced chi-squared = 0.8780475 for 57 degrees of freedom
Null hypothesis probability = 0.731
Photon flux (15-150 keV) in 1.000 sec: 0.999708 ( -0.219928 0.222642 ) ph/cm2/s
Energy fluence (15-150 keV) : 9.50042e-08 ( -1.94545e-08 1.95128e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 1.080 sec. to 2.080 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.753664 ( )
Epeak [keV] : 363.164 ( )
Norm@50keV : 1.065009E-02 ( )
------------------------------------------------------------
Chi-Squared = 50.05415 using 59 PHA bins.
Reduced chi-squared = 0.8938240 for 56 degrees of freedom
Null hypothesis probability = 0.698
Photon flux (15-150 keV) in 1.000 sec: ( ) ph/cm2/s
Energy fluence (15-150 keV) : 0 ( 0 0 ) ergs/cm2
Band function
Time interval is from 1.080 sec. to 2.080 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.864248 ( -14.2558 0.744248 )
beta : -0.971026 ( -0.372782 0.396182 )
Epeak [keV] : 20.7722 ( -20.6722 9979.23 )
Norm@50keV : 1.367839E-02 ( -408.796 2712.48 )
------------------------------------------------------------
Chi-Squared = 50.04871 using 59 PHA bins.
Reduced chi-squared = 0.9099765 for 55 degrees of freedom
Null hypothesis probability = 0.664
Photon flux (15-150 keV) in 1.000 sec: ( ) ph/cm2/s
Energy fluence (15-150 keV) : 0 ( 0 0 ) ergs/cm2
Plot creation:
Fri Dec 14 01:05:19 EST 2007