batgrbproduct Analysis for Trigger=178750
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): Mon Dec 31 09:57:08 EST 2007
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger178750/SDC
======================================================================
Trigger: 00178750 Segment: 000
BAT Trigger Time: 159810892.8 [s; MET]
Trigger Stop: 159810893.824 [s; MET]
UTC: 2006-01-24T15:54:51.825540 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 77.0434182139533 Dec: 69.7093915850525 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 6.59
Image Trigger?: NO
Rate S/N Ratio: 10.7238052947636 [ if not an image trigger ]
Image S/N Ratio: 6.59
Flight Position: [ source = BAT ]
RA: 77.0434182139533 Dec: 69.7093915850525 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 77.0881504949215 Dec: 69.7239818375151 [deg; J2000]
{ 05h 08m 21.2s , +69d 43' 26.3" }
+/- 1.73191118550489 [arcmin] (estimated 90% radius based on SNR)
+/- 0.721453542914654 [arcmin] (formal 1-sigma fit error)
SNR: 13.8792979322254
RA = 5h 8m 21.2s (77.088150 deg.)
Dec = 69d 43' 26" (69.723982 deg.)
Angular difference between Flight and Ground position is 1.277511 arcmin
Partial Coding Fraction: 0.6171875 [ including projection effects ]
Duration
T90: 13.6320000290871 +/- 1.30678232181628
Measured from: -0.936000019311905
to: 12.6960000097752 [s; relative to TRIGTIME]
T50: 7.39599999785423 +/- 2.44399671740983
Measured from: 1.05199998617172
to: 8.44799998402596 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 0.187999993562698
to: 1.1879999935627 [s; relative to TRIGTIME]
Total Fluence
Measured from: -1.62800002098083
to: 13.1879999935627 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.258782 0.293547 0.169567 0.058266
0.024611 0.025433 0.023147 0.022105 [error]
Peak 0.027892 0.039656 0.025232 0.014089
0.006568 0.006871 0.006443 0.005750 [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 8.81e-08 1.32e-07 1.47e-07 3.12e-07 4.61e-07 6.77e-07 erg/cm2
Error 1.37e-08 1.30e-08 2.33e-08 1.02e-07 5.34e-08 1.24e-07 erg/cm2
Peak flux Power-law 3.28e-01 2.99e-01 1.88e-01 1.81e-01 8.91e-01 9.96e-01 ph/cm2/s
Error 1.03e-01 6.07e-02 5.30e-02 1.01e-01 1.79e-01 2.02e-01 ph/cm2/s
Fluence Cutoff-PL 8.81e-08 1.32e-07 1.47e-07 3.09e-07 4.61e-07 6.96e-07 erg/cm2
Error 1.37e-08 1.30e-08 2.33e-08 1.01e-07 5.34e-08 1.25e-07 erg/cm2
Peak flux Cutoff-PL 3.02e-01 3.18e-01 1.96e-01 9.52e-02 8.74e-01 9.11e-01 ph/cm2/s
Error 8.80e-02 7.50e-02 6.02e-02 1.31e-01 1.82e-01 2.34e-01 ph/cm2/s
Fluence Band 8.58e-08 1.35e-07 1.45e-07 2.88e-07 4.56e-07 6.52e-07 erg/cm2
Error 1.47e-08 1.70e-08 2.50e-08 1.36e-07 5.63e-08 1.57e-07 erg/cm2
Peak flux Band 3.02e-01 3.18e-01 1.96e-01 9.53e-02 8.74e-01 9.11e-01 ph/cm2/s
Error 1.18e-01 7.54e-02 6.02e-02 1.29e-01 1.82e-01 2.33e-01 ph/cm2/s
=== Time-averaged spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.839 0.189 - - 3.39e-03 3.87e-04 54.897 57
CPL 1.789 0.000 181.8 0.0 3.61e-03 3.88e-04 54.956 56
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.669 0.354 - - 6.78e-03 1.49e-03 48.319 57
CPL 1.089 1.376 74.8 5000.0 1.38e-02 4.90e-02 47.674 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: 3.200000 sec.
T50 in the 50-300 keV band: 1.472000 sec.
=== Table of the duration information ==
Value tstart tstop
T100 14.816 -1.628 13.188
T90 13.632 -0.936 12.696
T50 7.396 1.052 8.448
Peak 1.000 0.188 1.188
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
77.0882 +69.7240 0.0138 37.8 -158.3 0.8376 13.9 TRIG_00178750
------------------------------------------
Foreground time interval of the image:
-1.628 13.188 (delta_t = 14.816 [sec])
Background time interval of the image:
-24.195 -1.628 (delta_t = 22.567 [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 -1.628 sec. to 13.188 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.83869 ( -0.186314 0.192457 )
Norm@50keV : 3.385489E-03 ( -3.907352E-04 3.823151E-04) )
------------------------------------------------------------
Chi-Squared = 54.89718 using 59 PHA bins.
Reduced chi-squared = 0.9631085 for 57 degrees of freedom
Null hypothesis probability = 0.554
Photon flux (15-150 keV) in 14.82 sec: 0.473696 ( -0.047483 0.04755 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.61327e-07 ( -5.29118e-08 5.38989e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -1.628 sec. to 13.188 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.78886 ( )
Epeak [keV] : 181.773 ( )
Norm@50keV : 3.608003E-03 ( -4.011095E-04 3.755945E-04) )
------------------------------------------------------------
Chi-Squared = 54.95564 using 59 PHA bins.
Reduced chi-squared = 0.9813508 for 56 degrees of freedom
Null hypothesis probability = 0.514
Photon flux (15-150 keV) in 14.82 sec: 0.473533 ( -0.047465 0.047533 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.61434e-07 ( -5.30482e-08 5.37907e-08 ) ergs/cm2
Band function
Time interval is from -1.628 sec. to 13.188 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.06095 ( -8.93904 5.31280 )
beta : -1.90558 ( -8.09442 0.232736 )
Epeak [keV] : 35.5436 ( -35.4436 9964.46 )
Norm@50keV : 1.162525E-02 ( -0.279289 352.368 )
------------------------------------------------------------
Chi-Squared = 54.33183 using 59 PHA bins.
Reduced chi-squared = 0.9878514 for 55 degrees of freedom
Null hypothesis probability = 0.500
Photon flux (15-150 keV) in 14.82 sec: 0.469682 ( -0.050289 0.047121 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.55896e-07 ( -5.79758e-08 5.4548e-08 ) ergs/cm2
Peak spectrum fit using the pre-slew DRM
Power-law model
Time interval is from 0.188 sec. to 1.188 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.66909 ( -0.344185 0.364700 )
Norm@50keV : 6.777594E-03 ( -1.508686E-03 1.462874E-03) )
------------------------------------------------------------
Chi-Squared = 48.31916 using 59 PHA bins.
Reduced chi-squared = 0.8477046 for 57 degrees of freedom
Null hypothesis probability = 0.787
Photon flux (15-150 keV) in 1.000 sec: 0.890631 ( -0.178807 0.178999 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.29385e-08 ( -1.44855e-08 1.48421e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.188 sec. to 1.188 sec.
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.08939 ( -1.60972 1.14296 )
Epeak [keV] : 74.7582 ( -74.7482 9925.24 )
Norm@50keV : 1.375601E-02 ( -1.375601E-02 8.426682E-02) )
------------------------------------------------------------
Chi-Squared = 47.67398 using 59 PHA bins.
but latest trial 2.04346 gives Chi-Squared = 1.56902
Reduced chi-squared = 0.8513210 for 56 degrees of freedom
Null hypothesis probability = 0.778
Photon flux (15-150 keV) in 1.000 sec: 0.874332 ( -0.182447 0.181998 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.05546e-08 ( -1.5499e-08 1.57185e-08 ) ergs/cm2
Band function
Time interval is from 0.188 sec. to 1.188 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.09527 ( -8.90473 1.33631 )
beta : -8.66208 ( -1.33792 7.29278 )
Epeak [keV] : 75.1600 ( -75.0600 9924.84 )
Norm@50keV : 1.364677E-02 ( -1.364677E-02 8.451584E-02) )
------------------------------------------------------------
Chi-Squared = 47.67392 using 59 PHA bins.
Reduced chi-squared = 0.8667986 for 55 degrees of freedom
Null hypothesis probability = 0.748
Photon flux (15-150 keV) in 1.000 sec: 0.874316 ( -0.182465 0.182264 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.04959e-08 ( -1.54677e-08 1.5733e-08 ) ergs/cm2
Plot creation:
Mon Dec 31 10:07:10 EST 2007