batgrbproduct Analysis for Trigger=312958
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 Jun 2 10:11:59 EDT 2008
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger312958/SDC
======================================================================
Trigger: 00312958 Segment: 000
BAT Trigger Time: 234063030.912 [s; MET]
Trigger Stop: 234063032.96 [s; MET]
UTC: 2008-06-02T01:30:28.077080 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 19.1726774847547 Dec: -9.25077306570324 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 8.11
Image Trigger?: NO
Rate S/N Ratio: 13.3790881602597 [ if not an image trigger ]
Image S/N Ratio: 8.11
Flight Position: [ source = BAT ]
RA: 19.1726774847547 Dec: -9.25077306570324 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 19.1773149963115 Dec: -9.23883402557759 [deg; J2000]
{ 01h 16m 42.6s , -09d 14' 19.8" }
+/- 1.7325011366993 [arcmin] (estimated 90% radius based on SNR)
+/- 0.761414681550076 [arcmin] (formal 1-sigma fit error)
SNR: 13.8725467423614
Angular difference between Flight and Ground position is 0.767184 arcmin
Partial Coding Fraction: 0.1972656 [ including projection effects ]
Duration
T90: 74.2680000066757 +/- 7.15611626957373
Measured from: -9.78000000119209
to: 64.4880000054836 [s; relative to TRIGTIME]
T50: 58.9760000109673 +/- 1.19500291774825
Measured from: 1.20800000429153
to: 60.1840000152588 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 59.5959999859333
to: 60.5959999859333 [s; relative to TRIGTIME]
Total Fluence
Measured from: -11.4880000054836
to: 69.3079999983311 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.980287 1.521488 1.550791 0.356908
0.105653 0.108770 0.104316 0.100131 [error]
Peak 0.037419 0.116626 0.148466 0.053289
0.007606 0.008549 0.009189 0.007835 [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 4.01e-07 7.68e-07 1.14e-06 3.65e-06 3.22e-06 5.94e-06 erg/cm2
Error 5.66e-08 6.49e-08 9.80e-08 6.98e-07 2.46e-07 7.54e-07 erg/cm2
Peak flux Power-law 6.25e-01 8.71e-01 8.98e-01 1.69e+00 2.93e+00 4.09e+00 ph/cm2/s
Error 1.06e-01 9.13e-02 6.72e-02 2.69e-01 2.38e-01 3.13e-01 ph/cm2/s
Fluence Cutoff-PL 3.53e-07 7.96e-07 1.21e-06 2.01e-06 3.16e-06 4.37e-06 erg/cm2
Error 7.24e-08 7.34e-08 1.22e-07 1.26e-06 2.57e-07 1.25e-06 erg/cm2
Peak flux Cutoff-PL 5.36e-01 8.90e-01 9.69e-01 1.10e+00 2.89e+00 3.50e+00 ph/cm2/s
Error 1.33e-01 9.87e-02 9.81e-02 4.95e-01 2.39e-01 5.46e-01 ph/cm2/s
Fluence Band 3.50e-07 7.93e-07 1.21e-06 2.03e-06 3.16e-06 4.38e-06 erg/cm2
Error 7.17e-08 7.32e-08 1.22e-07 8.45e-07 2.57e-07 8.92e-07 erg/cm2
Peak flux Band 4.48e-01 9.47e-01 9.40e-01 1.42e+00 2.83e+00 3.76e+00 ph/cm2/s
Error 1.70e-01 1.12e-01 9.57e-02 3.73e-01 2.44e-01 4.21e-01 ph/cm2/s
=== Time-averaged spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.429 0.128 - - 4.14e-03 3.02e-04 50.093 57
CPL 0.910 0.567 119.0 3764.7 7.12e-03 4.45e-03 47.330 0
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 0.956 0.129 - - 2.55e-02 2.03e-03 58.475 57
CPL 0.425 0.574 182.0 4942.4 4.28e-02 2.51e-02 55.746 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: 72.896000 sec.
T50 in the 50-300 keV band: 59.200000 sec.
=== Table of the duration information ==
Value tstart tstop
T100 80.796 -11.488 69.308
T90 74.268 -9.780 64.488
T50 58.976 1.208 60.184
Peak 1.000 59.596 60.596
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
19.1773 -9.2388 0.0139 51.3 -0.8 2.7358 13.9 TRIG_00312958
------------------------------------------
Foreground time interval of the image:
-11.488 33.293 (delta_t = 44.781 [sec])
Background time interval of the image:
-276.707 -11.488 (delta_t = 265.219 [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 -11.488 sec. to 69.308 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.42911 ( -0.128441 0.128080 )
Norm@50keV : 4.143935E-03 ( -3.017907E-04 3.017797E-04) )
------------------------------------------------------------
Chi-Squared = 50.09345 using 59 PHA bins.
Reduced chi-squared = 0.8788325 for 57 degrees of freedom
Null hypothesis probability = 0.730
Photon flux (15-150 keV) in 80.80 sec: 0.508091 ( -0.040348 0.04054 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.21703e-06 ( -2.45252e-07 2.45907e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -11.488 sec. to 69.308 sec.
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.909818 ( -0.606450 0.527583 )
Epeak [keV] : 119.021 ( -36.3732 7493.01 )
Norm@50keV : 7.120116E-03 ( -2.932764E-03 5.972967E-03) )
------------------------------------------------------------
Chi-Squared = 47.33049 using 59 PHA bins.
but latest trial 4.178043E-03 gives Chi-Squared = 2.75431
Reduced chi-squared = 0.8451873 for 56 degrees of freedom
Null hypothesis probability = 0.789
Photon flux (15-150 keV) in 80.80 sec: 0.494903 ( -0.042481 0.042527 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.15925e-06 ( -2.56984e-07 2.573e-07 ) ergs/cm2
Band function
Time interval is from -11.488 sec. to 69.308 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.877329 ( -0.561185 0.575347 )
beta : -8.63633 ( -1.36367 7.21746 )
Epeak [keV] : 115.225 ( -32.6228 9737.21 )
Norm@50keV : 7.360399E-03 ( -3.224001E-03 5.757923E-03) )
------------------------------------------------------------
Chi-Squared = 47.34118 using 59 PHA bins.
Reduced chi-squared = 0.8607487 for 55 degrees of freedom
Null hypothesis probability = 0.759
Photon flux (15-150 keV) in 80.80 sec: 0.494898 ( -0.042486 0.042672 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.1583e-06 ( -2.58075e-07 2.55756e-07 ) ergs/cm2
Peak spectrum fit using the pre-slew DRM
Power-law model
Time interval is from 59.596 sec. to 60.596 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.955549 ( -0.131307 0.126900 )
Norm@50keV : 2.551152E-02 ( -2.040124E-03 2.018383E-03) )
------------------------------------------------------------
Chi-Squared = 58.47540 using 59 PHA bins.
Reduced chi-squared = 1.025884 for 57 degrees of freedom
Null hypothesis probability = 0.421
Photon flux (15-150 keV) in 1.000 sec: 2.93152 ( -0.23754 0.23843 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.80341e-07 ( -2.111e-08 2.114e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 59.596 sec. to 60.596 sec.
Parameters : value lower 90% higher 90%
Photon index: 0.425274 ( -0.619909 0.528563 )
Epeak [keV] : 181.998 ( -66.8639 9818.00 )
Norm@50keV : 4.275346E-02 ( -1.655767E-02 3.367895E-02) )
------------------------------------------------------------
Chi-Squared = 55.74582 using 59 PHA bins.
but latest trial 0.953883 gives Chi-Squared = 2.53842
but latest trial 2.631187E-02 gives Chi-Squared = 3.51888
Reduced chi-squared = 0.9954610 for 56 degrees of freedom
Null hypothesis probability = 0.484
Photon flux (15-150 keV) in 1.000 sec: 2.89495 ( -0.23852 0.24027 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.78927e-07 ( -2.1844e-08 2.1608e-08 ) ergs/cm2
Band function
Time interval is from 59.596 sec. to 60.596 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : 0.887128 ( -3.82706 1.61132 )
beta : -1.19674 ( -0.176063 0.169073 )
Epeak [keV] : 68.9981 ( -12.6935 127.865 )
Norm@50keV : 0.237952 ( -11.6064 66.1433 )
------------------------------------------------------------
Chi-Squared = 52.88729 using 59 PHA bins.
Reduced chi-squared = 0.9615872 for 55 degrees of freedom
Null hypothesis probability = 0.556
Photon flux (15-150 keV) in 1.000 sec: 2.83292 ( -0.24545 0.24189 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.7561e-07 ( -2.1711e-08 2.1244e-08 ) ergs/cm2
Plot creation:
Mon Jun 2 10:42:46 EDT 2008