batgrbproduct Analysis for Trigger=286809
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 06:25:46 EST 2007
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger286809/SDC
======================================================================
Trigger: 00286809 Segment: 000
BAT Trigger Time: 207731248 [s; MET]
Trigger Stop: 207731312 [s; MET]
UTC: 2007-08-02T07:07:25.872160 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 36.850987019423 Dec: -55.5364556715457 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 7.15
Image Trigger?: YES
Rate S/N Ratio: 0 [ if not an image trigger ]
Image S/N Ratio: 7.15
Flight Position: [ source = BAT ]
RA: 36.850987019423 Dec: -55.5364556715457 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 36.9043963624921 Dec: -55.5109967666254 [deg; J2000]
{ 02h 27m 37.1s , -55d 30' 39.6" }
+/- 2.00529269807257 [arcmin] (estimated 90% radius based on SNR)
+/- 1.06973912368035 [arcmin] (formal 1-sigma fit error)
SNR: 11.2573416823303
RA = 2h 27m 37.1s (36.904396 deg.)
Dec = -55d 30' 40" (-55.510997 deg.)
Angular difference between Flight and Ground position is 2.371480 arcmin
Partial Coding Fraction: 0.734375 [ including projection effects ]
Duration
T90: 16.9079999923706 +/- 3.01981259231406
Measured from: 5.54800000786781
to: 22.4560000002384 [s; relative to TRIGTIME]
T50: 6.96400001645088 +/- 2.78514127583814
Measured from: 8.43999999761581
to: 15.4040000140667 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 6.15200001001358
to: 7.15200001001358 [s; relative to TRIGTIME]
Total Fluence
Measured from: 4.80399999022484
to: 24.3120000064373 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.153412 0.206410 0.092849 0.049804
0.024491 0.024453 0.021342 0.018723 [error]
Peak 0.021410 0.013463 0.013935 0.005997
0.005517 0.005872 0.004882 0.004089 [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 5.12e-08 7.82e-08 8.96e-08 1.96e-07 2.77e-07 4.18e-07 erg/cm2
Error 1.13e-08 1.14e-08 2.10e-08 9.40e-08 4.86e-08 1.15e-07 erg/cm2
Peak flux Power-law 2.11e-01 1.46e-01 6.60e-02 4.15e-02 4.43e-01 4.65e-01 ph/cm2/s
Error 9.77e-02 5.25e-02 5.60e-02 5.87e-02 1.39e-01 1.51e-01 ph/cm2/s
Fluence Cutoff-PL 4.92e-08 8.25e-08 8.95e-08 9.65e-08 2.66e-07 3.13e-07 erg/cm2
Error 1.26e-08 1.55e-08 2.31e-08 1.47e-07 5.57e-08 1.56e-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 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 4.64e-01 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 1.805 0.272 - - 1.54e-03 2.64e-04 48.347 57
CPL 1.188 0.000 57.7 5000.0 3.40e-03 7.72e-03 48.036 56
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 2.143 0.920 - - 2.76e-03 1.49e-03 65.166 57
CPL 2.223 0.000 96.5 0.0 2.35e-03 0.00e+00 64.985 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 19.508 4.804 24.312
T90 16.908 5.548 22.456
T50 6.964 8.440 15.404
Peak 1.000 6.152 7.152
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
36.9044 -55.5110 0.0171 25.4 28.5 0.5253 11.3 TRIG_00286809
------------------------------------------
Foreground time interval of the image:
4.804 24.312 (delta_t = 19.508 [sec])
Background time interval of the image:
-130.795 4.804 (delta_t = 135.599 [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 4.804 sec. to 24.312 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.80476 ( -0.264755 0.279406 )
Norm@50keV : 1.544718E-03 ( -2.684044E-04 2.603913E-04) )
------------------------------------------------------------
Chi-Squared = 48.34654 using 59 PHA bins.
Reduced chi-squared = 0.8481849 for 57 degrees of freedom
Null hypothesis probability = 0.786
Photon flux (15-150 keV) in 19.51 sec: 0.213250 ( -0.031306 0.031322 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.77415e-07 ( -4.80434e-08 4.92452e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 4.804 sec. to 24.312 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.18784 ( )
Epeak [keV] : 57.6980 ( -69.6242 9930.37 )
Norm@50keV : 3.399351E-03 ( -2.365487E-03 1.308280E-02) )
------------------------------------------------------------
Chi-Squared = 48.03561 using 59 PHA bins.
Reduced chi-squared = 0.8577788 for 56 degrees of freedom
Null hypothesis probability = 0.767
Photon flux (15-150 keV) in 19.51 sec: 0.210181 ( -0.03244 0.032254 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.66452e-07 ( -5.5067e-08 5.63176e-08 ) ergs/cm2
Band function
Time interval is from 4.804 sec. to 24.312 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.14523 ( -8.85477 4.97505 )
beta : -2.05813 ( -7.94187 0.490048 )
Epeak [keV] : 50.1756 ( -50.0756 407.249 )
Norm@50keV : 3.829267E-03 ( -3.829267E-03 206.012 )
------------------------------------------------------------
Chi-Squared = 47.81171 using 59 PHA bins.
Reduced chi-squared = 0.8693038 for 55 degrees of freedom
Null hypothesis probability = 0.743
Photon flux (15-150 keV) in 19.51 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 6.152 sec. to 7.152 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.14289 ( -0.694689 1.14434 )
Norm@50keV : 2.757749E-03 ( -1.684669E-03 1.299275E-03) )
------------------------------------------------------------
Chi-Squared = 65.16558 using 59 PHA bins.
Reduced chi-squared = 1.143256 for 57 degrees of freedom
Null hypothesis probability = 0.214
Photon flux (15-150 keV) in 1.000 sec: 0.443463 ( -0.139117 0.139108 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.57564e-08 ( -1.15324e-08 1.1717e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 6.152 sec. to 7.152 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.22316 ( )
Epeak [keV] : 96.4566 ( )
Norm@50keV : 2.354704E-03 ( )
------------------------------------------------------------
Chi-Squared = 64.98494 using 59 PHA bins.
Reduced chi-squared = 1.160445 for 56 degrees of freedom
Null hypothesis probability = 0.192
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 6.152 sec. to 7.152 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.54226 ( -5.38416 4.02121 )
beta : -3.04085 ( -1.13971 0.697919 )
Epeak [keV] : 56.4529 ( -56.3529 9943.55 )
Norm@50keV : 4.559733E-03 ( -0.374096 0.177428 )
------------------------------------------------------------
Chi-Squared = 66.12431 using 59 PHA bins.
Reduced chi-squared = 1.202260 for 55 degrees of freedom
Null hypothesis probability = 0.145
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 06:47:26 EST 2007