batgrbproduct Analysis for Trigger=312047
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): Wed May 21 06:12:46 EDT 2008
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger312047/GCN5_download_cron
======================================================================
Trigger: 00312047 Segment: 000
BAT Trigger Time: 233014827.584 [s; MET]
Trigger Stop: 233014829.632 [s; MET]
UTC: 2008-05-20T22:20:24.778640 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 280.191885316142 Dec: -55.003825646117 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 8.7
Image Trigger?: NO
Rate S/N Ratio: 10.6301458127346 [ if not an image trigger ]
Image S/N Ratio: 8.7
Flight Position: [ source = BAT ]
RA: 280.191885316142 Dec: -55.003825646117 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 280.178888400121 Dec: -54.9642781569657 [deg; J2000]
{ 18h 40m 42.9s , -54d 57' 51.4" }
+/- 2.41476465599094 [arcmin] (estimated 90% radius based on SNR)
+/- 1.18546089198844 [arcmin] (formal 1-sigma fit error)
SNR: 8.63285337756041
Angular difference between Flight and Ground position is 2.414671 arcmin
Partial Coding Fraction: 1 [ including projection effects ]
Duration
T90: 2.82400000095367 +/- 0.658401081811059
Measured from: -0.135999977588654
to: 2.68800002336502 [s; relative to TRIGTIME]
T50: 1.62799999117851 +/- 0.63449193880696
Measured from: 0.256000012159348
to: 1.88400000333786 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: -0.311999976634979
to: 0.688000023365021 [s; relative to TRIGTIME]
Total Fluence
Measured from: -0.319999992847443
to: 2.84800001978874 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.082066 0.050278 0.002742 0.008262
0.010196 0.009480 0.008049 0.006948 [error]
Peak 0.032300 0.023016 0.001827 0.001255
0.005789 0.005374 0.004516 0.003875 [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 2.33e-08 1.85e-08 9.89e-09 7.70e-09 5.52e-08 5.92e-08 erg/cm2
Error 5.12e-09 4.99e-09 5.54e-09 9.33e-09 1.41e-08 1.83e-08 erg/cm2
Peak flux Power-law 2.50e-01 1.53e-01 6.05e-02 3.20e-02 4.80e-01 4.96e-01 ph/cm2/s
Error 8.40e-02 4.49e-02 3.23e-02 3.70e-02 1.31e-01 1.37e-01 ph/cm2/s
Fluence Cutoff-PL 2.30e-08 2.02e-08 7.22e-09 9.43e-10 5.12e-08 5.13e-08 erg/cm2
Error 5.47e-09 6.21e-09 7.49e-09 8.09e-09 1.40e-08 1.83e-08 erg/cm2
Peak flux Cutoff-PL 2.30e-01 1.90e-01 4.36e-02 1.84e-03 4.65e-01 4.65e-01 ph/cm2/s
Error 9.75e-02 6.56e-02 3.85e-02 2.58e-02 1.29e-01 1.29e-01 ph/cm2/s
Fluence Band 2.28e-08 2.01e-08 7.14e-09 9.17e-10 5.10e-08 5.15e-08 erg/cm2
Error 5.01e-09 4.61e-09 5.66e-09 6.66e-09 1.40e-08 1.04e-08 erg/cm2
Peak flux Band 2.32e-01 1.88e-01 4.40e-02 2.05e-03 4.64e-01 4.71e-01 ph/cm2/s
Error 7.68e-02 5.48e-02 2.24e-02 2.76e-02 1.27e-01 1.30e-01 ph/cm2/s
=== Time-averaged spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 2.903 0.511 - - 1.51e-03 6.34e-04 53.609 57
CPL 1.742 1.450 7.1 13.1 9.21e-03 3.30e-01 52.781 56
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 2.343 0.548 - - 2.68e-03 1.11e-03 49.170 57
CPL 0.418 2.495 28.7 21.0 4.65e-02 1.81e+00 47.264 0
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 3.168 -0.320 2.848
T90 2.824 -0.136 2.688
T50 1.628 0.256 1.884
Peak 1.000 -0.312 0.688
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
280.1789 -54.9643 0.0224 17.4 -158.0 0.1514 8.6 TRIG_00312047
------------------------------------------
Foreground time interval of the image:
-0.320 2.848 (delta_t = 3.168 [sec])
Background time interval of the image:
-137.383 -0.320 (delta_t = 137.063 [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 -0.320 sec. to 2.848 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.90326 ( -0.459763 0.561391 )
Norm@50keV : 1.512055E-03 ( -6.122050E-04 6.556122E-04) )
------------------------------------------------------------
Chi-Squared = 53.60941 using 59 PHA bins.
Reduced chi-squared = 0.9405159 for 57 degrees of freedom
Null hypothesis probability = 0.603
Photon flux (15-150 keV) in 3.168 sec: 0.387924 ( -0.075759 0.075846 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.51603e-08 ( -1.3503e-08 1.46453e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.320 sec. to 2.848 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.74245 ( -2.64677 0.252306 )
Epeak [keV] : 7.05623 ( -7.04623 19.0774 )
Norm@50keV : 9.214663E-03 ( -9.214663E-03 0.651726 )
------------------------------------------------------------
Chi-Squared = 52.78111 using 59 PHA bins.
Reduced chi-squared = 0.9425197 for 56 degrees of freedom
Null hypothesis probability = 0.597
Photon flux (15-150 keV) in 3.168 sec: 0.382021 ( -0.074817 0.074621 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.12288e-08 ( -1.22228e-08 1.58318e-08 ) ergs/cm2
Band function
Time interval is from -0.320 sec. to 2.848 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.41929 ( -8.58071 0.569833 )
beta : -8.86649 ( -1.13351 18.8664 )
Epeak [keV] : 12.4697 ( -12.3697 7.62151 )
Norm@50keV : 1.511374E-02 ( -1.511374E-02 0.664361 )
------------------------------------------------------------
Chi-Squared = 52.86067 using 59 PHA bins.
Reduced chi-squared = 0.9611031 for 55 degrees of freedom
Null hypothesis probability = 0.557
Photon flux (15-150 keV) in 3.168 sec: 0.393057 ( -0.076342 0.075972 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.10365e-08 ( -1.18771e-08 1.60627e-08 ) ergs/cm2
Peak spectrum fit using the pre-slew DRM
Power-law model
Time interval is from -0.312 sec. to 0.688 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.34329 ( -0.498847 0.597657 )
Norm@50keV : 2.681711E-03 ( -1.109388E-03 1.106901E-03) )
------------------------------------------------------------
Chi-Squared = 49.17048 using 59 PHA bins.
Reduced chi-squared = 0.8626400 for 57 degrees of freedom
Null hypothesis probability = 0.760
Photon flux (15-150 keV) in 1.000 sec: 0.480216 ( -0.130754 0.130834 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.58344e-08 ( -8.4613e-09 9.1932e-09 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.312 sec. to 0.688 sec.
Epeak [keV] : 28.6708 ( -26.8436 15.1525 )
Norm@50keV : 4.646519E-02 ( -4.646520E-02 3.57070 )
------------------------------------------------------------
Chi-Squared = 47.26403 using 59 PHA bins.
but latest trial 2.01716 gives Chi-Squared = 3.12165
but latest trial 1.83272 gives Chi-Squared = 1.15102
but latest trial 56.9301 gives Chi-Squared = 3.13401
but latest trial 5.81522 gives Chi-Squared = 8.52339
Reduced chi-squared = 0.8440005 for 56 degrees of freedom
Null hypothesis probability = 0.791
Photon flux (15-150 keV) in 1.000 sec: 0.465138 ( -0.127912 0.129442 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.23262e-08 ( -6.7147e-09 9.1761e-09 ) ergs/cm2
Band function
Time interval is from -0.312 sec. to 0.688 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.774366 ( -9.22563 4.95452 )
beta : -9.31674 ( )
Epeak [keV] : 27.6969 ( )
Norm@50keV : 2.730032E-02 ( )
------------------------------------------------------------
Chi-Squared = 47.35740 using 59 PHA bins.
Reduced chi-squared = 0.8610437 for 55 degrees of freedom
Null hypothesis probability = 0.758
Photon flux (15-150 keV) in 1.000 sec: 0.464307 ( -0.126756 0.128188 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.21527e-08 ( -6.7518e-09 9.7279e-09 ) ergs/cm2
Plot creation:
Wed May 21 07:11:05 EDT 2008