batgrbproduct Analysis for Trigger=282808
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 02:54:04 EST 2007
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger282808/SDC
======================================================================
Trigger: 00282808 Segment: 000
BAT Trigger Time: 204160661.888 [s; MET]
Trigger Stop: 204160662.912 [s; MET]
UTC: 2007-06-21T23:17:39.850480 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 323.80441851629 Dec: -24.80574107457 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 9.01
Image Trigger?: NO
Rate S/N Ratio: 17.2916164657906 [ if not an image trigger ]
Image S/N Ratio: 9.01
Flight Position: [ source = BAT ]
RA: 323.80441851629 Dec: -24.80574107457 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 323.805273065559 Dec: -24.8083267443047 [deg; J2000]
{ 21h 35m 13.3s , -24d 48' 30.0" }
+/- 0.862371125570424 [arcmin] (estimated 90% radius based on SNR)
+/- 0.260971837694709 [arcmin] (formal 1-sigma fit error)
SNR: 37.5823384137107
RA = 21h 35m 13.3s (323.805273 deg.)
Dec = -24d 48' 30" (-24.808327 deg.)
Angular difference between Flight and Ground position is 0.161971 arcmin
Partial Coding Fraction: 0.3164062 [ including projection effects ]
Duration
T90: 33.2960000038147 +/- 2.77631123696316
Measured from: -2.15600001811981
to: 31.1399999856949 [s; relative to TRIGTIME]
T50: 17.5719999969006 +/- 0.782163673283351
Measured from: 4.42800000309944
to: 22 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 21.555999994278
to: 22.555999994278 [s; relative to TRIGTIME]
Total Fluence
Measured from: -5.19600000977516
to: 36.447999984026 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 1.757609 2.354437 1.914158 0.488299
0.067585 0.067157 0.058979 0.045530 [error]
Peak 0.072674 0.109863 0.088439 0.036563
0.010904 0.011294 0.010167 0.007751 [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 6.28e-07 1.11e-06 1.49e-06 4.13e-06 4.33e-06 7.34e-06 erg/cm2
Error 4.40e-08 4.46e-08 5.94e-08 3.83e-07 1.48e-07 4.09e-07 erg/cm2
Peak flux Power-law 7.64e-01 8.23e-01 6.31e-01 7.89e-01 2.52e+00 3.01e+00 ph/cm2/s
Error 1.72e-01 1.11e-01 8.17e-02 2.22e-01 3.05e-01 3.37e-01 ph/cm2/s
Fluence Cutoff-PL 6.18e-07 1.11e-06 1.50e-06 3.77e-06 4.32e-06 6.99e-06 erg/cm2
Error 5.40e-08 4.57e-08 6.69e-08 8.33e-07 1.17e-07 8.43e-07 erg/cm2
Peak flux Cutoff-PL 7.63e-01 8.24e-01 6.31e-01 7.84e-01 2.51e+00 3.00e+00 ph/cm2/s
Error 1.72e-01 1.11e-01 8.18e-02 2.20e-01 3.04e-01 3.37e-01 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 7.48e-01 8.17e-01 6.35e-01 8.06e-01 2.51e+00 3.02e+00 ph/cm2/s
Error 9.95e-02 1.09e-01 7.68e-02 1.72e-01 2.96e-01 0.00e+00 ph/cm2/s
=== Time-averaged spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.570 0.064 - - 1.11e-02 3.70e-04 39.244 57
CPL 1.499 0.191 406.3 4954.1 1.19e-02 2.27e-03 39.013 56
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.385 0.205 - - 2.07e-02 2.31e-03 61.228 57
CPL 1.381 0.206 9991.5 5000.0 2.08e-02 2.32e-03 61.242 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: 32.384000 sec.
T50 in the 50-300 keV band: 18.432000 sec.
=== Table of the duration information ==
Value tstart tstop
T100 41.644 -5.196 36.448
T90 33.296 -2.156 31.140
T50 17.572 4.428 22.000
Peak 1.000 21.556 22.556
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
323.8053 -24.8083 0.0051 43.1 15.6 4.2214 37.6 TRIG_00282808
------------------------------------------
Foreground time interval of the image:
-5.196 17.917 (delta_t = 23.113 [sec])
Background time interval of the image:
-239.888 -5.196 (delta_t = 234.692 [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 -5.196 sec. to 36.448 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.56988 ( -6.385887E-02 6.385517E-02) )
Norm@50keV : 1.108313E-02 ( -3.697956E-04 3.697481E-04) )
------------------------------------------------------------
Chi-Squared = 39.24357 using 59 PHA bins.
Reduced chi-squared = 0.6884837 for 57 degrees of freedom
Null hypothesis probability = 0.965
Photon flux (15-150 keV) in 41.64 sec: 1.41127 ( -0.05505 0.05535 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.3326e-06 ( -1.47489e-07 1.47739e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -5.196 sec. to 36.448 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.49930 ( -0.252696 0.129712 )
Epeak [keV] : 406.266 ( -314.483 9593.73 )
Norm@50keV : 1.190821E-02 ( -1.151734E-03 3.385921E-03) )
------------------------------------------------------------
Chi-Squared = 39.01262 using 59 PHA bins.
Reduced chi-squared = 0.6966538 for 56 degrees of freedom
Null hypothesis probability = 0.959
Photon flux (15-150 keV) in 41.64 sec: 1.40388 ( -0.04768 0.05442 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.31886e-06 ( -7.73255e-08 1.57191e-07 ) ergs/cm2
Band function
Time interval is from -5.196 sec. to 36.448 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.03058 ( -9.59942 1.95669 )
beta : -1.57283 ( -6.671071E-02 6.530905E-02) )
Epeak [keV] : 39.9746 ( -334.117 9531.92 )
Norm@50keV : 2.951346E-02 ( -1.030144E-03 2792.99 )
------------------------------------------------------------
Chi-Squared = 39.14836 using 59 PHA bins.
Reduced chi-squared = 0.7117883 for 55 degrees of freedom
Null hypothesis probability = 0.948
Photon flux (15-150 keV) in 41.64 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 21.556 sec. to 22.556 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.38456 ( -0.206246 0.203190 )
Norm@50keV : 2.072828E-02 ( -2.314202E-03 2.314011E-03) )
------------------------------------------------------------
Chi-Squared = 61.22780 using 59 PHA bins.
Reduced chi-squared = 1.074172 for 57 degrees of freedom
Null hypothesis probability = 0.327
Photon flux (15-150 keV) in 1.000 sec: 2.51562 ( -0.30375 0.30533 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.00906e-07 ( -2.3824e-08 2.3949e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 21.556 sec. to 22.556 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.38134 ( -0.207669 0.204457 )
Epeak [keV] : 9991.47 ( -9991.46 8.53223 )
Norm@50keV : 2.080594E-02 ( -2.322562E-03 2.322534E-03) )
------------------------------------------------------------
Chi-Squared = 61.24159 using 59 PHA bins.
Reduced chi-squared = 1.093600 for 56 degrees of freedom
Null hypothesis probability = 0.293
Photon flux (15-150 keV) in 1.000 sec: 2.51475 ( -0.30364 0.30523 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.00895e-07 ( -2.3779e-08 2.4007e-08 ) ergs/cm2
Band function
Time interval is from 21.556 sec. to 22.556 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.00158 ( -9.31842 3.29347 )
beta : -1.38713 ( -5.20043 0.209291 )
Epeak [keV] : 54.9499 ( -38.4159 3943.81 )
Norm@50keV : 4.248528E-02 ( -1.95675 5406.77 )
------------------------------------------------------------
Chi-Squared = 61.20885 using 59 PHA bins.
Reduced chi-squared = 1.112888 for 55 degrees of freedom
Null hypothesis probability = 0.263
Photon flux (15-150 keV) in 1.000 sec: 2.50832 ( -0.29173 0.30035 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.00793e-07 ( -2.3833e-08 2.3941e-08 ) ergs/cm2
Plot creation:
Fri Dec 14 03:10:12 EST 2007