batgrbproduct Analysis for Trigger=257741
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 11:56:11 EST 2007
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger257741/GCN5_download_cron
======================================================================
Trigger: 00257741 Segment: 000
BAT Trigger Time: 191471608 [s; MET]
Trigger Stop: 191471672 [s; MET]
UTC: 2007-01-26T02:33:26.277220 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 33.4603956656862 Dec: -73.5233322332982 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 7.04
Image Trigger?: YES
Rate S/N Ratio: 0 [ if not an image trigger ]
Image S/N Ratio: 7.04
Flight Position: [ source = BAT ]
RA: 33.4603956656862 Dec: -73.5233322332982 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 33.5220139316693 Dec: -73.5469752595029 [deg; J2000]
{ 02h 14m 05.3s , -73d 32' 49.1" }
+/- 4.04906580855426 [arcmin] (estimated 90% radius based on SNR)
+/- 2.33145769421398 [arcmin] (formal 1-sigma fit error)
SNR: 4.12542423224347
RA = 2h 14m 5.3s (33.522014 deg.)
Dec = -73d 32' 49" (-73.546975 deg.)
Angular difference between Flight and Ground position is 1.763626 arcmin
Partial Coding Fraction: 0.9921875 [ including projection effects ]
Duration
T90: 64 +/-
Measured from: 0
to: 64 [s; relative to TRIGTIME]
T50: 64 +/-
Measured from: 0
to: 64 [s; relative to TRIGTIME]
WARNING: battblocks failed. Used TDRSS fore/background intervals
Fluence
Peak Flux (peak 64 second)
Measured from: 0
to: 64 [s; relative to TRIGTIME]
Total Fluence
Measured from: 0
to: 64 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.110069 0.189526 0.023997 -0.000086
0.036065 0.036212 0.032328 0.028906 [error]
Peak 0.110069 0.189526 0.023997 -0.000086
0.036065 0.036212 0.032328 0.028906 [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 3.72e-08 4.96e-08 4.84e-08 8.48e-08 1.63e-07 2.14e-07 erg/cm2
Error 1.37e-08 1.57e-08 2.51e-08 7.84e-08 6.15e-08 1.18e-07 erg/cm2
Peak flux Power-law 1.90e-02 1.40e-02 6.82e-03 4.73e-03 4.20e-02 4.45e-02 ph/cm2/s
Error 7.10e-03 4.37e-03 3.43e-03 5.16e-03 1.29e-02 1.40e-02 ph/cm2/s
Fluence Cutoff-PL 3.51e-08 7.54e-08 2.04e-08 2.08e-10 1.31e-07 1.31e-07 erg/cm2
Error 1.26e-08 2.22e-08 2.45e-08 3.02e-09 3.94e-08 3.94e-08 erg/cm2
Peak flux Cutoff-PL 1.72e-02 2.14e-02 3.31e-03 1.86e-05 4.19e-02 4.19e-02 ph/cm2/s
Error 6.24e-03 6.03e-03 3.72e-03 2.49e-04 1.14e-02 1.13e-02 ph/cm2/s
Fluence Band 3.26e-08 7.70e-08 1.82e-08 2.24e-10 1.30e-07 1.43e-07 erg/cm2
Error 2.32e-08 1.98e-08 1.87e-10 4.83e-08 6.03e-08 0.00e+00 erg/cm2
Peak flux Band 1.86e-02 2.20e-02 2.96e-03 1.86e-05 4.14e-02 3.83e-02 ph/cm2/s
Error 6.23e-03 3.41e-03 8.22e-04 1.12e-02 1.29e-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 2.034 0.511 - - 2.76e-04 1.10e-04 46.750 57
CPL -2.496 0.000 33.7 7.4 2.48e-01 3.27e-01 38.655 56
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 2.034 0.511 - - 2.76e-04 1.10e-04 46.750 57
CPL -2.496 0.000 33.7 7.4 2.48e-01 3.27e-01 38.655 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 64.000 0.000 64.000
T90 64.000 0.000 64.000
T50 64.000 0.000 64.000
Peak 64.000 0.000 64.000
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
33.5220 -73.5470 0.0464 6.1 92.0 0.2932 4.1 TRIG_00257741
------------------------------------------
Foreground time interval of the image:
0.000 64.000 (delta_t = 64.000 [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 64.000 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.03387 ( -0.475322 0.546780 )
Norm@50keV : 2.755316E-04 ( -1.094418E-04 1.098966E-04) )
------------------------------------------------------------
Chi-Squared = 46.75001 using 59 PHA bins.
Reduced chi-squared = 0.8201756 for 57 degrees of freedom
Null hypothesis probability = 0.832
Photon flux (15-150 keV) in 64.00 sec: 4.200408E-02 ( -0.0128309 0.0128769 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.63055e-07 ( -5.88902e-08 6.42086e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.000 sec. to 64.000 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -2.49608 ( )
Epeak [keV] : 33.6733 ( -6.31811 8.53378 )
Norm@50keV : 0.247856 ( -0.263708 0.390842 )
------------------------------------------------------------
Chi-Squared = 38.65478 using 59 PHA bins.
Reduced chi-squared = 0.6902639 for 56 degrees of freedom
Null hypothesis probability = 0.963
Photon flux (15-150 keV) in 64.00 sec: 4.193637E-02 ( -0.0113552 0.0113655 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.31174e-07 ( -3.78541e-08 4.096e-08 ) ergs/cm2
Band function
Time interval is from 0.000 sec. to 64.000 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : 0.123121 ( -4.61488 6.688309E-02) )
beta : -9.32281 ( -2.53734 4.85218 )
Epeak [keV] : 35.8524 ( -7.10772 5.87097 )
Norm@50keV : 6.622601E-03 ( -11.9369 33.6968 )
------------------------------------------------------------
Chi-Squared = 41.00924 using 59 PHA bins.
Reduced chi-squared = 0.7456225 for 55 degrees of freedom
Null hypothesis probability = 0.920
Photon flux (15-150 keV) in 64.00 sec: 4.144660E-02 ( -0.0112044 0.0111434 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.2955e-07 ( -3.50586e-08 6.16096e-08 ) ergs/cm2
Peak spectrum fit using the pre-slew DRM
Power-law model
Time interval is from 0.000 sec. to 64.000 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.03387 ( -0.475322 0.546780 )
Norm@50keV : 2.755316E-04 ( -1.094418E-04 1.098966E-04) )
------------------------------------------------------------
Chi-Squared = 46.75001 using 59 PHA bins.
Reduced chi-squared = 0.8201756 for 57 degrees of freedom
Null hypothesis probability = 0.832
Photon flux (15-150 keV) in 64.00 sec: 4.200408E-02 ( -0.0128309 0.0128769 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.63055e-07 ( -5.88902e-08 6.42086e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.000 sec. to 64.000 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -2.49608 ( )
Epeak [keV] : 33.6733 ( -6.31811 8.53378 )
Norm@50keV : 0.247856 ( -0.263708 0.390842 )
------------------------------------------------------------
Chi-Squared = 38.65478 using 59 PHA bins.
Reduced chi-squared = 0.6902639 for 56 degrees of freedom
Null hypothesis probability = 0.963
Photon flux (15-150 keV) in 64.00 sec: 4.193637E-02 ( -0.0113552 0.0113655 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.31174e-07 ( -3.78541e-08 4.096e-08 ) ergs/cm2
Band function
Time interval is from 0.000 sec. to 64.000 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : 0.123121 ( -4.61488 6.688309E-02) )
beta : -9.32281 ( -2.53734 4.85218 )
Epeak [keV] : 35.8524 ( -7.10772 5.87097 )
Norm@50keV : 6.622601E-03 ( -11.9369 33.6968 )
------------------------------------------------------------
Chi-Squared = 41.00924 using 59 PHA bins.
Reduced chi-squared = 0.7456225 for 55 degrees of freedom
Null hypothesis probability = 0.920
Photon flux (15-150 keV) in 64.00 sec: 4.144660E-02 ( -0.0112044 0.0111434 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.2955e-07 ( -3.50586e-08 6.16096e-08 ) ergs/cm2
Plot creation:
Thu Dec 13 12:22:51 EST 2007