batgrbproduct Analysis for Trigger=151905
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): Tue Jan 8 17:59:42 EST 2008
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger151905/SDC
======================================================================
Trigger: 00151905 Segment: 000
BAT Trigger Time: 146617936 [s; MET]
Trigger Stop: 146618000 [s; MET]
UTC: 2005-08-24T23:12:16.307660 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 12.2370524365621 Dec: 22.592045480018 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 8.76
Image Trigger?: YES
Rate S/N Ratio: 0 [ if not an image trigger ]
Image S/N Ratio: 8.76
Flight Position: [ source = BAT ]
RA: 12.2370524365621 Dec: 22.592045480018 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 12.2593246507722 Dec: 22.6020686599829 [deg; J2000]
{ 00h 49m 02.2s , +22d 36' 07.4" }
+/- 2.06526584988267 [arcmin] (estimated 90% radius based on SNR)
+/- 1.07428823266064 [arcmin] (formal 1-sigma fit error)
SNR: 10.7932619485456
RA = 0h 49m 2.2s (12.259325 deg.)
Dec = 22d 36' 7" (22.602069 deg.)
Angular difference between Flight and Ground position is 1.372513 arcmin
Partial Coding Fraction: 0.75 [ including projection effects ]
Duration
T90: 22.5760000050068 +/- 4.07092717497179
Measured from: 37.9079999923706
to: 60.4839999973774 [s; relative to TRIGTIME]
T50: 8.02399998903275 +/- 4.67293911444453
Measured from: 46.0640000104904
to: 54.0879999995232 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 53.1279999911785
to: 54.1279999911785 [s; relative to TRIGTIME]
Total Fluence
Measured from: 36.5679999887943
to: 63.136000007391 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.320425 0.183133 0.066742 -0.001041
0.030009 0.031024 0.028431 0.028046 [error]
Peak 0.022982 0.017130 0.015543 -0.000236
0.005839 0.006140 0.005439 0.005589 [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 1.04e-07 8.96e-08 5.29e-08 4.68e-08 2.67e-07 2.92e-07 erg/cm2
Error 1.80e-08 1.74e-08 2.18e-08 3.59e-08 5.19e-08 7.16e-08 erg/cm2
Peak flux Power-law 2.08e-01 1.66e-01 8.94e-02 7.01e-02 4.96e-01 5.34e-01 ph/cm2/s
Error 9.17e-02 5.09e-02 4.51e-02 7.13e-02 1.52e-01 1.68e-01 ph/cm2/s
Fluence Cutoff-PL 1.03e-07 9.25e-08 4.75e-08 1.94e-08 2.56e-07 2.64e-07 erg/cm2
Error 1.84e-08 2.05e-08 2.89e-08 4.18e-08 4.30e-08 8.31e-08 erg/cm2
Peak flux Cutoff-PL 2.07e-01 1.68e-01 8.91e-02 5.90e-02 4.94e-01 5.23e-01 ph/cm2/s
Error 9.43e-02 5.15e-02 6.78e-02 8.12e-02 1.51e-01 1.80e-01 ph/cm2/s
Fluence Band 1.05e-07 9.04e-08 5.50e-08 5.04e-08 2.63e-07 3.47e-07 erg/cm2
Error 1.70e-08 1.32e-08 2.02e-08 2.95e-08 4.13e-08 0.00e+00 erg/cm2
Peak flux Band 2.04e-01 1.86e-01 8.08e-02 4.85e-02 4.95e-01 5.20e-01 ph/cm2/s
Error 9.81e-02 6.63e-02 3.80e-02 4.36e-02 1.52e-01 1.65e-01 ph/cm2/s
=== Time-averaged spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 2.760 0.381 - - 9.22e-04 2.80e-04 49.852 57
CPL 1.981 0.416 0.8 10.9 3.04e-03 2.05e-03 49.824 0
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.895 0.605 - - 3.46e-03 1.34e-03 54.755 57
CPL 1.789 1.304 81.2 5000.0 4.00e-03 3.10e-01 54.747 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 26.568 36.568 63.136
T90 22.576 37.908 60.484
T50 8.024 46.064 54.088
Peak 1.000 53.128 54.128
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
12.2593 +22.6021 0.0177 32.6 -22.5 0.6570 10.8 TRIG_00151905
------------------------------------------
Foreground time interval of the image:
36.568 63.136 (delta_t = 26.568 [sec])
Background time interval of the image:
-196.099 36.568 (delta_t = 232.667 [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 36.568 sec. to 63.136 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.76032 ( -0.353234 0.408250 )
Norm@50keV : 9.223779E-04 ( -2.761924E-04 2.847374E-04) )
------------------------------------------------------------
Chi-Squared = 49.85199 using 59 PHA bins.
Reduced chi-squared = 0.8745964 for 57 degrees of freedom
Null hypothesis probability = 0.738
Photon flux (15-150 keV) in 26.57 sec: 0.214343 ( -0.031447 0.031465 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.66502e-07 ( -5.02181e-08 5.35917e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 36.568 sec. to 63.136 sec.
Parameters : value lower 90% higher 90%
Photon index: 1.98121 ( -0.818590 1.304233E-02) )
Epeak [keV] : 0.785826 ( -0.553365 21.2385 )
Norm@50keV : 3.041576E-03 ( -3.041576E-03 1.055561E-03) )
------------------------------------------------------------
Chi-Squared = 49.82405 using 59 PHA bins.
but latest trial 1.16262 gives Chi-Squared = 109.595
but latest trial 4.821213E-03 gives Chi-Squared = 4.28087
Reduced chi-squared = 0.8897153 for 56 degrees of freedom
Null hypothesis probability = 0.706
Photon flux (15-150 keV) in 26.57 sec: 0.212219 ( -0.031889 0.032021 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.55796e-07 ( -5.46162e-08 3.1304e-08 ) ergs/cm2
Band function
Time interval is from 36.568 sec. to 63.136 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.71384 ( -8.28616 6.71384 )
beta : -7.67306 ( -7.23362 12.7648 )
Epeak [keV] : 6.76114 ( -6.65834 15.2258 )
Norm@50keV : 5.906241E-03 ( -5.675486E-03 112.957 )
------------------------------------------------------------
Chi-Squared = 51.03808 using 59 PHA bins.
Reduced chi-squared = 0.9279651 for 55 degrees of freedom
Null hypothesis probability = 0.627
Photon flux (15-150 keV) in 26.57 sec: 0.212232 ( -0.031931 0.032183 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.62811e-07 ( -4.14072e-08 4.11017e-08 ) ergs/cm2
Peak spectrum fit using the pre-slew DRM
Power-law model
Time interval is from 53.128 sec. to 54.128 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.89481 ( -0.567848 0.641830 )
Norm@50keV : 3.462511E-03 ( -1.383912E-03 1.296590E-03) )
------------------------------------------------------------
Chi-Squared = 54.75462 using 59 PHA bins.
Reduced chi-squared = 0.9606073 for 57 degrees of freedom
Null hypothesis probability = 0.560
Photon flux (15-150 keV) in 1.000 sec: 0.495814 ( -0.151768 0.151778 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.18355e-08 ( -1.17121e-08 1.25327e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 53.128 sec. to 54.128 sec.
Parameters : value lower 90% higher 90%
Photon index: 1.78944 ( -2.13274 0.474666 )
Epeak [keV] : 81.1875 ( -81.1775 9918.81 )
Norm@50keV : 4.001369E-03 ( -4.001369E-03 0.616103 )
------------------------------------------------------------
Chi-Squared = 54.74670 using 59 PHA bins.
but latest trial -2.05399 gives Chi-Squared = 7.55665
but latest trial 2.26410 gives Chi-Squared = 0.293602
Reduced chi-squared = 0.9776196 for 56 degrees of freedom
Null hypothesis probability = 0.522
Photon flux (15-150 keV) in 1.000 sec: 0.494250 ( -0.151218 0.151219 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.13485e-08 ( -1.35415e-08 1.299e-08 ) ergs/cm2
Band function
Time interval is from 53.128 sec. to 54.128 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.28237 ( -8.71763 6.28237 )
beta : -1.96369 ( -8.03631 0.613539 )
Epeak [keV] : 33.6118 ( -33.5118 9966.39 )
Norm@50keV : 9.376444E-03 ( -228.812 262.573 )
------------------------------------------------------------
Chi-Squared = 54.55135 using 59 PHA bins.
Reduced chi-squared = 0.9918426 for 55 degrees of freedom
Null hypothesis probability = 0.492
Photon flux (15-150 keV) in 1.000 sec: 0.495121 ( -0.150035 0.153438 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.99404e-08 ( -1.23452e-08 1.12071e-08 ) ergs/cm2
Plot creation:
Tue Jan 8 18:09:11 EST 2008