batgrbproduct Analysis for Trigger=279592
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 22:01:25 EST 2007
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger279592/GCN5_download_cron
======================================================================
Trigger: 00279592 Segment: 000
BAT Trigger Time: 201191183.168 [s; MET]
Trigger Stop: 201191184.192 [s; MET]
UTC: 2007-05-18T14:26:21.204860 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 254.223225939659 Dec: 55.2965244404127 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 7.22
Image Trigger?: NO
Rate S/N Ratio: 12.2065556157337 [ if not an image trigger ]
Image S/N Ratio: 7.22
Flight Position: [ source = BAT ]
RA: 254.223225939659 Dec: 55.2965244404127 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 254.215783034261 Dec: 55.2984047797795 [deg; J2000]
{ 16h 56m 51.8s , +55d 17' 54.3" }
+/- 1.78854659144531 [arcmin] (estimated 90% radius based on SNR)
+/- 0.888573010850685 [arcmin] (formal 1-sigma fit error)
SNR: 13.2557323261284
RA = 16h 56m 51.8s (254.215783 deg.)
Dec = 55d 17' 54" (55.298405 deg.)
Angular difference between Flight and Ground position is 0.278150 arcmin
Partial Coding Fraction: 0.84375 [ including projection effects ]
Duration
T90: 4.9200000166893 +/- 0.808170787953849
Measured from: -0.732000023126602
to: 4.1879999935627 [s; relative to TRIGTIME]
T50: 2.88800001144409 +/- 0.941912938210134
Measured from: -0.316000014543533
to: 2.57199999690056 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 0.123999983072281
to: 1.12399998307228 [s; relative to TRIGTIME]
Total Fluence
Measured from: -1.78400000929832
to: 4.50399997830391 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.132422 0.127028 0.047461 -0.003382
0.012962 0.012879 0.011093 0.009219 [error]
Peak 0.034299 0.031531 0.012532 0.000490
0.005370 0.005332 0.004600 0.003702 [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 3.94e-08 5.02e-08 4.67e-08 7.62e-08 1.62e-07 2.13e-07 erg/cm2
Error 6.62e-09 6.10e-09 1.07e-08 3.45e-08 2.40e-08 4.65e-08 erg/cm2
Peak flux Power-law 3.34e-01 2.20e-01 9.46e-02 5.57e-02 6.76e-01 7.04e-01 ph/cm2/s
Error 8.49e-02 4.43e-02 3.69e-02 4.10e-02 1.29e-01 1.37e-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 3.85e-08 5.12e-08 4.56e-08 2.01e-07 0.00e+00 0.00e+00 erg/cm2
Error 7.00e-09 7.27e-09 1.18e-08 5.11e-08 0.00e+00 0.00e+00 erg/cm2
Peak flux Band 3.31e-01 2.24e-01 9.36e-02 4.35e-02 6.73e-01 6.92e-01 ph/cm2/s
Error 8.88e-02 5.52e-02 4.29e-02 5.05e-02 1.31e-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 2.106 0.247 - - 2.77e-03 4.55e-04 63.907 57
CPL 1.946 0.000 14.2 0.0 3.42e-03 0.00e+00 63.882 56
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 2.220 0.415 - - 4.04e-03 1.19e-03 61.934 57
CPL 1.932 0.000 9.4 0.0 6.00e-03 0.00e+00 61.930 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 6.288 -1.784 4.504
T90 4.920 -0.732 4.188
T50 2.888 -0.316 2.572
Peak 1.000 0.124 1.124
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
254.2158 +55.2984 0.0145 18.8 -56.4 0.3112 13.3 TRIG_00279592
------------------------------------------
Foreground time interval of the image:
-1.784 4.504 (delta_t = 6.288 [sec])
Background time interval of the image:
-239.168 -174.218 (delta_t = 64.950 [sec])
-173.168 -56.119 (delta_t = 117.049 [sec])
-55.168 -1.784 (delta_t = 53.384 [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 -1.784 sec. to 4.504 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.10644 ( -0.238076 0.255983 )
Norm@50keV : 2.770933E-03 ( -4.619802E-04 4.472996E-04) )
------------------------------------------------------------
Chi-Squared = 63.90714 using 59 PHA bins.
Reduced chi-squared = 1.121178 for 57 degrees of freedom
Null hypothesis probability = 0.247
Photon flux (15-150 keV) in 6.288 sec: 0.437330 ( -0.05183 0.05184 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.62052e-07 ( -2.36781e-08 2.42585e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -1.784 sec. to 4.504 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.94599 ( )
Epeak [keV] : 14.1566 ( )
Norm@50keV : 3.417753E-03 ( )
------------------------------------------------------------
Chi-Squared = 63.88232 using 59 PHA bins.
Reduced chi-squared = 1.140756 for 56 degrees of freedom
Null hypothesis probability = 0.219
Photon flux (15-150 keV) in 6.288 sec: ( ) ph/cm2/s
Energy fluence (15-150 keV) : 0 ( 0 0 ) ergs/cm2
Band function
Time interval is from -1.784 sec. to 4.504 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.53729 ( -5.09597 7.19365 )
beta : -2.30796 ( -0.255934 0.238319 )
Epeak [keV] : 27.8963 ( -27.7963 9972.10 )
Norm@50keV : 6.399332E-03 ( -6.276894E-02 6.081751E-02) )
------------------------------------------------------------
Chi-Squared = 64.08355 using 59 PHA bins.
Reduced chi-squared = 1.165155 for 55 degrees of freedom
Null hypothesis probability = 0.188
Photon flux (15-150 keV) in 6.288 sec: 0.435529 ( -0.053957 0.053113 ) 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 0.124 sec. to 1.124 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.21973 ( -0.383804 0.445511 )
Norm@50keV : 4.042252E-03 ( -1.212008E-03 1.162047E-03) )
------------------------------------------------------------
Chi-Squared = 61.93443 using 59 PHA bins.
Reduced chi-squared = 1.086569 for 57 degrees of freedom
Null hypothesis probability = 0.304
Photon flux (15-150 keV) in 1.000 sec: 0.676227 ( -0.128605 0.128629 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.81296e-08 ( -9.2827e-09 9.8054e-09 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.124 sec. to 1.124 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.93242 ( )
Epeak [keV] : 9.36237 ( )
Norm@50keV : 5.995648E-03 ( )
------------------------------------------------------------
Chi-Squared = 61.93038 using 59 PHA bins.
Reduced chi-squared = 1.105900 for 56 degrees of freedom
Null hypothesis probability = 0.273
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 0.124 sec. to 1.124 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.89357 ( -7.51365 7.48635 )
beta : -9.13400 ( -0.445284 0.383788 )
Epeak [keV] : 12.3461 ( -12.2461 9987.65 )
Norm@50keV : 6.431131E-03 ( -0.164729 0.157948 )
------------------------------------------------------------
Chi-Squared = 61.94862 using 59 PHA bins.
Reduced chi-squared = 1.126339 for 55 degrees of freedom
Null hypothesis probability = 0.242
Photon flux (15-150 keV) in 1.000 sec: 0.673214 ( -0.131527 0.130628 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.83313e-08 ( -7.2822e-09 8.6422e-09 ) ergs/cm2
Plot creation:
Thu Dec 13 22:17:41 EST 2007