batgrbproduct Analysis for Trigger=258408
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 12:24:09 EST 2007
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger258408/SDC
======================================================================
Trigger: 00258408 Segment: 000
BAT Trigger Time: 191806512 [s; MET]
Trigger Stop: 191806576 [s; MET]
UTC: 2007-01-29T23:35:10.269080 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 37.0138693588457 Dec: 11.6974043453265 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 7.28
Image Trigger?: YES
Rate S/N Ratio: 0 [ if not an image trigger ]
Image S/N Ratio: 7.28
Flight Position: [ source = BAT ]
RA: 37.0138693588457 Dec: 11.6974043453265 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 36.9930024017318 Dec: 11.733178000945 [deg; J2000]
{ 02h 27m 58.3s , +11d 43' 59.4" }
+/- 2.73235837609566 [arcmin] (estimated 90% radius based on SNR)
+/- 1.45465121524812 [arcmin] (formal 1-sigma fit error)
SNR: 7.23590989642755
RA = 2h 27m 58.3s (36.993002 deg.)
Dec = 11d 43' 59" (11.733178 deg.)
Angular difference between Flight and Ground position is 2.471849 arcmin
Partial Coding Fraction: 0.4257812 [ including projection effects ]
Duration
T90: 460.628000020981 +/- 24.2660876097569
Measured from: -97.5640000104904
to: 363.06400001049 [s; relative to TRIGTIME]
T50: 279.727999985218 +/- 27.2261113442386
Measured from: 33.0040000081062
to: 312.731999993324 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 310.567999988794
to: 311.567999988794 [s; relative to TRIGTIME]
Total Fluence
Measured from: -125.020000010729
to: 374.048000007868 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 2.179902 2.264271 1.030358 0.170733
0.135211 0.138270 0.124566 0.112388 [error]
Peak 0.028019 0.024172 0.016480 0.007152
0.005125 0.005152 0.004641 0.003682 [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 7.08e-07 9.37e-07 9.10e-07 1.58e-06 3.07e-06 4.13e-06 erg/cm2
Error 8.28e-08 7.05e-08 1.22e-07 4.30e-07 2.72e-07 5.50e-07 erg/cm2
Peak flux Power-law 2.59e-01 1.98e-01 1.01e-01 7.40e-02 5.92e-01 6.32e-01 ph/cm2/s
Error 7.77e-02 4.29e-02 3.71e-02 5.20e-02 1.28e-01 1.39e-01 ph/cm2/s
Fluence Cutoff-PL 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 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 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 2.53e-01 2.10e-01 9.48e-02 5.88e-02 5.90e-01 6.19e-01 ph/cm2/s
Error 8.50e-02 5.42e-02 4.21e-02 5.03e-02 1.29e-01 1.47e-01 ph/cm2/s
=== Time-averaged spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 2.042 0.155 - - 6.66e-04 6.31e-05 63.420 57
CPL 1.390 0.000 40.9 0.0 1.51e-03 0.00e+00 62.741 56
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.970 0.411 - - 4.00e-03 1.12e-03 41.900 57
CPL 1.445 0.000 43.5 0.0 8.15e-03 0.00e+00 41.594 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: 102.720000 sec.
T50 in the 50-300 keV band: 35.520000 sec.
=== Table of the duration information ==
Value tstart tstop
T100 499.068 -125.020 374.048
T90 460.628 -97.564 363.064
T50 279.728 33.004 312.732
Peak 1.000 310.568 311.568
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
36.9930 +11.7332 0.0265 29.0 79.3 2.4586 7.2 TRIG_00258408
------------------------------------------
Foreground time interval of the image:
-125.020 75.805 (delta_t = 200.825 [sec])
Background time interval of the image:
-239.000 -125.020 (delta_t = 113.980 [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 -125.020 sec. to 374.048 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.04211 ( -0.152211 0.158492 )
Norm@50keV : 6.661030E-04 ( -6.369746E-05 6.244169E-05) )
------------------------------------------------------------
Chi-Squared = 63.41965 using 59 PHA bins.
Reduced chi-squared = 1.112625 for 57 degrees of freedom
Null hypothesis probability = 0.260
Photon flux (15-150 keV) in 499.1 sec: 0.101900 ( -0.00783056 0.007844 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.07396e-06 ( -2.69639e-07 2.73432e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -125.020 sec. to 374.048 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.39028 ( )
Epeak [keV] : 40.8882 ( )
Norm@50keV : 1.514140E-03 ( )
------------------------------------------------------------
Chi-Squared = 62.74064 using 59 PHA bins.
Reduced chi-squared = 1.120369 for 56 degrees of freedom
Null hypothesis probability = 0.250
Photon flux (15-150 keV) in 499.1 sec: ( ) ph/cm2/s
Energy fluence (15-150 keV) : 0 ( 0 0 ) ergs/cm2
Band function
Time interval is from -125.020 sec. to 374.048 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.37492 ( -8.62508 1.56473 )
beta : -2.45709 ( -7.54291 0.531189 )
Epeak [keV] : 39.0744 ( -38.9744 9960.93 )
Norm@50keV : 1.588262E-03 ( -1.588262E-03 0.332090 )
------------------------------------------------------------
Chi-Squared = 62.30423 using 59 PHA bins.
Reduced chi-squared = 1.132804 for 55 degrees of freedom
Null hypothesis probability = 0.232
Photon flux (15-150 keV) in 499.1 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 310.568 sec. to 311.568 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.96995 ( -0.386573 0.435902 )
Norm@50keV : 4.000518E-03 ( -1.147990E-03 1.092992E-03) )
------------------------------------------------------------
Chi-Squared = 41.89956 using 59 PHA bins.
Reduced chi-squared = 0.7350799 for 57 degrees of freedom
Null hypothesis probability = 0.933
Photon flux (15-150 keV) in 1.000 sec: 0.591942 ( -0.127532 0.127533 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.67905e-08 ( -9.6186e-09 1.01693e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 310.568 sec. to 311.568 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.44470 ( )
Epeak [keV] : 43.4759 ( )
Norm@50keV : 8.146617E-03 ( )
------------------------------------------------------------
Chi-Squared = 41.59378 using 59 PHA bins.
Reduced chi-squared = 0.7427460 for 56 degrees of freedom
Null hypothesis probability = 0.924
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 310.568 sec. to 311.568 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.40638 ( -10.9308 4.06920 )
beta : -2.68504 ( -0.929374 4.76895 )
Epeak [keV] : 45.9580 ( -26.5997 485.359 )
Norm@50keV : 8.296458E-03 ( -505.073 160.831 )
------------------------------------------------------------
Chi-Squared = 41.57986 using 59 PHA bins.
Reduced chi-squared = 0.7559975 for 55 degrees of freedom
Null hypothesis probability = 0.909
Photon flux (15-150 keV) in 1.000 sec: 0.590374 ( -0.129317 0.129579 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.5019e-08 ( -9.9793e-09 1.13983e-08 ) ergs/cm2
Plot creation:
Thu Dec 13 12:39:53 EST 2007