batgrbproduct Analysis for Trigger=279494
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 21:44:45 EST 2007
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger279494/GCN5_download_cron
======================================================================
Trigger: 00279494 Segment: 000
BAT Trigger Time: 201093660.352 [s; MET]
Trigger Stop: 201093663.424 [s; MET]
UTC: 2007-05-17T11:20:58.391320 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 277.579460915099 Dec: -62.3326989655416 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 8
Image Trigger?: NO
Rate S/N Ratio: 11.2694276695846 [ if not an image trigger ]
Image S/N Ratio: 8
Flight Position: [ source = BAT ]
RA: 277.579460915099 Dec: -62.3326989655416 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 277.60476095726 Dec: -62.3008140136223 [deg; J2000]
{ 18h 30m 25.1s , -62d 18' 02.9" }
+/- 1.97676915355807 [arcmin] (estimated 90% radius based on SNR)
+/- 0.768398991779375 [arcmin] (formal 1-sigma fit error)
SNR: 11.4901092439756
RA = 18h 30m 25.1s (277.604761 deg.)
Dec = -62d 18' 3" (-62.300814 deg.)
Angular difference between Flight and Ground position is 2.038946 arcmin
Partial Coding Fraction: 0.671875 [ including projection effects ]
Duration
T90: 9 +/- 3.16227766016838
Measured from: -0.351999998092651
to: 8.64800000190735 [s; relative to TRIGTIME]
T50: 5 +/- 1
Measured from: 0.648000001907349
to: 5.64800000190735 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 1.64800000190735
to: 2.64800000190735 [s; relative to TRIGTIME]
Total Fluence
Measured from: -0.351999998092651
to: 10.6480000019073 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.164761 0.170704 0.110952 0.009744
0.022701 0.021199 0.017943 0.015661 [error]
Peak 0.036895 0.027012 0.023703 0.002429
0.006988 0.006611 0.005694 0.004853 [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 4.85e-08 7.40e-08 8.46e-08 1.85e-07 2.62e-07 3.92e-07 erg/cm2
Error 9.88e-09 9.87e-09 1.74e-08 7.77e-08 4.06e-08 9.45e-08 erg/cm2
Peak flux Power-law 3.18e-01 2.58e-01 1.41e-01 1.13e-01 7.68e-01 8.30e-01 ph/cm2/s
Error 1.06e-01 5.44e-02 4.86e-02 7.89e-02 1.63e-01 1.77e-01 ph/cm2/s
Fluence Cutoff-PL 4.58e-08 7.95e-08 8.40e-08 7.25e-08 2.48e-07 2.78e-07 erg/cm2
Error 1.10e-08 1.35e-08 1.98e-08 1.16e-07 4.59e-08 1.31e-07 erg/cm2
Peak flux Cutoff-PL 3.18e-01 2.58e-01 1.41e-01 1.12e-01 7.68e-01 8.30e-01 ph/cm2/s
Error 1.06e-01 5.44e-02 4.87e-02 7.84e-02 1.63e-01 1.76e-01 ph/cm2/s
Fluence Band 4.71e-08 7.93e-08 8.01e-08 1.46e-07 2.54e-07 3.07e-07 erg/cm2
Error 1.21e-08 1.21e-08 1.60e-08 6.43e-08 3.94e-08 0.00e+00 erg/cm2
Peak flux Band 3.18e-01 2.58e-01 1.41e-01 1.12e-01 7.68e-01 8.30e-01 ph/cm2/s
Error 1.06e-01 5.45e-02 4.87e-02 7.84e-02 1.63e-01 1.86e-01 ph/cm2/s
=== Time-averaged spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.807 0.242 - - 2.59e-03 3.92e-04 67.768 57
CPL 1.087 1.030 55.0 5000.0 6.56e-03 1.27e-02 66.786 56
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.869 0.431 - - 5.42e-03 1.40e-03 38.703 57
CPL 1.859 1.436 669.6 0.0 5.49e-03 5.54e-03 38.710 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: 6.272000 sec.
T50 in the 50-300 keV band: 1.344000 sec.
=== Table of the duration information ==
Value tstart tstop
T100 11.000 -0.352 10.648
T90 9.000 -0.352 8.648
T50 5.000 0.648 5.648
Peak 1.000 1.648 2.648
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
277.6048 -62.3008 0.0167 22.0 -100.6 0.4637 11.5 TRIG_00279494
------------------------------------------
Foreground time interval of the image:
-0.352 10.648 (delta_t = 11.000 [sec])
Background time interval of the image:
-239.352 -147.962 (delta_t = 91.390 [sec])
-147.352 -0.352 (delta_t = 147.000 [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 -0.352 sec. to 10.648 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.80734 ( -0.238175 0.246602 )
Norm@50keV : 2.588027E-03 ( -3.965958E-04 3.880875E-04) )
------------------------------------------------------------
Chi-Squared = 67.76787 using 59 PHA bins.
Reduced chi-squared = 1.188910 for 57 degrees of freedom
Null hypothesis probability = 0.156
Photon flux (15-150 keV) in 11.00 sec: 0.357646 ( -0.048207 0.048262 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.62052e-07 ( -4.02523e-08 4.10058e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.352 sec. to 10.648 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.08742 ( -1.03706 1.02311 )
Epeak [keV] : 55.0325 ( -55.0225 9944.97 )
Norm@50keV : 6.561145E-03 ( -6.561145E-03 1.877258E-02) )
------------------------------------------------------------
Chi-Squared = 66.78597 using 59 PHA bins.
Reduced chi-squared = 1.192607 for 56 degrees of freedom
Null hypothesis probability = 0.153
Photon flux (15-150 keV) in 11.00 sec: 0.350157 ( -0.049864 0.048956 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.47684e-07 ( -4.56401e-08 4.60889e-08 ) ergs/cm2
Band function
Time interval is from -0.352 sec. to 10.648 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.10675 ( -8.89325 6.10675 )
beta : -1.97644 ( -8.02356 0.357291 )
Epeak [keV] : 44.4725 ( -34.3725 73.5483 )
Norm@50keV : 7.220476E-03 ( -99.0657 47.0831 )
------------------------------------------------------------
Chi-Squared = 66.66982 using 59 PHA bins.
Reduced chi-squared = 1.212178 for 55 degrees of freedom
Null hypothesis probability = 0.135
Photon flux (15-150 keV) in 11.00 sec: 0.353828 ( -0.048021 0.04986 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.54211e-07 ( -4.36887e-08 3.50152e-08 ) ergs/cm2
Peak spectrum fit using the pre-slew DRM
Power-law model
Time interval is from 1.648 sec. to 2.648 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.86930 ( -0.409128 0.452565 )
Norm@50keV : 5.420313E-03 ( -1.442824E-03 1.349998E-03) )
------------------------------------------------------------
Chi-Squared = 38.70267 using 59 PHA bins.
Reduced chi-squared = 0.6789942 for 57 degrees of freedom
Null hypothesis probability = 0.970
Photon flux (15-150 keV) in 1.000 sec: 0.767930 ( -0.162946 0.163232 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.98181e-08 ( -1.25314e-08 1.2989e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 1.648 sec. to 2.648 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.85920 ( -1.32475 1.54807 )
Epeak [keV] : 669.591 ( )
Norm@50keV : 5.489240E-03 ( -1.636591E-03 9.438115E-03) )
------------------------------------------------------------
Chi-Squared = 38.71025 using 59 PHA bins.
Reduced chi-squared = 0.6912545 for 56 degrees of freedom
Null hypothesis probability = 0.962
Photon flux (15-150 keV) in 1.000 sec: 0.767648 ( -0.162892 0.163178 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.98401e-08 ( -1.25522e-08 1.29724e-08 ) ergs/cm2
Band function
Time interval is from 1.648 sec. to 2.648 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.65312 ( -6.50342 6.86926 )
beta : -2.80643 ( -0.452537 0.409527 )
Epeak [keV] : 79.0484 ( -78.9484 9920.95 )
Norm@50keV : 6.996327E-03 ( -0.195960 0.183463 )
------------------------------------------------------------
Chi-Squared = 38.91790 using 59 PHA bins.
Reduced chi-squared = 0.7075983 for 55 degrees of freedom
Null hypothesis probability = 0.950
Photon flux (15-150 keV) in 1.000 sec: 0.767648 ( -0.162892 0.163178 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.9786e-08 ( -1.25522e-08 1.29639e-08 ) ergs/cm2
Plot creation:
Thu Dec 13 22:00:14 EST 2007