batgrbproduct Analysis for Trigger=279817
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): Thu Dec 13 22:19:00 EST 2007
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger279817/GCN5_download_cron
======================================================================
Trigger: 00279817 Segment: 000
BAT Trigger Time: 201359112 [s; MET]
Trigger Stop: 201359200 [s; MET]
UTC: 2007-05-20T13:05:10.032620 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 193.315762479148 Dec: 74.9932499437833 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 7.99
Image Trigger?: YES
Rate S/N Ratio: 0 [ if not an image trigger ]
Image S/N Ratio: 7.99
Flight Position: [ source = BAT ]
RA: 193.315762479148 Dec: 74.9932499437833 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 193.237955774953 Dec: 74.9822553043906 [deg; J2000]
{ 12h 52m 57.1s , +74d 58' 56.1" }
+/- 2.30937651452593 [arcmin] (estimated 90% radius based on SNR)
+/- 1.35006654934091 [arcmin] (formal 1-sigma fit error)
SNR: 9.20110894575833
RA = 12h 52m 57.1s (193.237956 deg.)
Dec = 74d 58' 56" (74.982255 deg.)
Angular difference between Flight and Ground position is 1.377471 arcmin
Partial Coding Fraction: 0.671875 [ including projection effects ]
Duration
T90: 48 +/- 22.6274169979695
Measured from: 17
to: 65 [s; relative to TRIGTIME]
T50: 16 +/- 22.6274169979695
Measured from: 33
to: 49 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 40.5
to: 41.5 [s; relative to TRIGTIME]
Total Fluence
Measured from: 17
to: 65 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.176683 0.266106 0.191175 -0.060600
0.040109 0.040144 0.035143 0.030152 [error]
Peak 0.078503 0.116157 0.105638 -0.002013
0.023270 0.023203 0.020428 0.017503 [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 6.55e-08 1.03e-07 1.22e-07 2.81e-07 3.72e-07 5.69e-07 erg/cm2
Error 1.80e-08 1.92e-08 3.35e-08 1.56e-07 8.00e-08 1.89e-07 erg/cm2
Peak flux Power-law 5.78e-02 5.38e-02 3.47e-02 3.45e-02 1.61e-01 1.81e-01 ph/cm2/s
Error 2.14e-02 1.26e-02 1.08e-02 2.17e-02 3.69e-02 4.14e-02 ph/cm2/s
Fluence Cutoff-PL 5.14e-08 1.20e-07 1.35e-07 6.43e-08 3.52e-07 3.71e-07 erg/cm2
Error 2.21e-08 2.49e-08 4.10e-08 1.03e-07 7.91e-08 1.32e-07 erg/cm2
Peak flux Cutoff-PL 5.02e-02 5.73e-02 3.73e-02 1.79e-02 1.56e-01 1.63e-01 ph/cm2/s
Error 2.60e-02 1.49e-02 1.27e-02 2.79e-02 3.81e-02 4.55e-02 ph/cm2/s
Fluence Band 5.07e-08 1.19e-07 1.35e-07 6.48e-08 3.52e-07 3.69e-07 erg/cm2
Error 2.19e-08 2.48e-08 4.06e-08 1.12e-07 7.90e-08 7.90e-08 erg/cm2
Peak flux Band 5.02e-02 5.72e-02 3.73e-02 1.80e-02 1.56e-01 1.63e-01 ph/cm2/s
Error 2.60e-02 1.49e-02 1.27e-02 2.79e-02 3.81e-02 4.82e-02 ph/cm2/s
=== Time-averaged spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.754 0.318 - - 8.41e-04 1.74e-04 70.983 57
CPL 0.233 1.529 57.9 37.2 4.95e-03 1.67e-02 67.069 56
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.633 0.408 - - 1.24e-03 3.00e-04 51.517 57
CPL 0.928 1.658 78.8 4970.8 2.76e-03 1.15e-02 50.813 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 48.000 17.000 65.000
T90 48.000 17.000 65.000
T50 16.000 33.000 49.000
Peak 1.000 40.500 41.500
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
193.2380 +74.9823 0.0210 30.0 -139.1 0.6924 9.2 TRIG_00279817
------------------------------------------
Foreground time interval of the image:
17.000 65.000 (delta_t = 48.000 [sec])
Background time interval of the image:
-239.000 -56.170 (delta_t = 182.830 [sec])
-55.000 17.000 (delta_t = 72.000 [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 17.000 sec. to 65.000 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.75447 ( -0.306449 0.329345 )
Norm@50keV : 8.411465E-04 ( -1.765820E-04 1.723765E-04) )
------------------------------------------------------------
Chi-Squared = 70.98253 using 59 PHA bins.
Reduced chi-squared = 1.245308 for 57 degrees of freedom
Null hypothesis probability = 0.101
Photon flux (15-150 keV) in 48.00 sec: 0.113924 ( -0.0213133 0.021342 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.72394e-07 ( -7.89403e-08 8.10288e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 17.000 sec. to 65.000 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.233344 ( -1.71648 1.34146 )
Epeak [keV] : 57.8647 ( -14.4637 59.9343 )
Norm@50keV : 4.946459E-03 ( -4.946459E-03 2.837009E-02) )
------------------------------------------------------------
Chi-Squared = 67.06892 using 59 PHA bins.
Reduced chi-squared = 1.197659 for 56 degrees of freedom
Null hypothesis probability = 0.148
Photon flux (15-150 keV) in 48.00 sec: 0.108444 ( -0.0218945 0.011024 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.51944e-07 ( -7.67976e-08 8.14714e-08 ) ergs/cm2
Band function
Time interval is from 17.000 sec. to 65.000 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.649308 ( -0.971748 1.86132 )
beta : -9.35738 ( -0.632620 7.44560 )
Epeak [keV] : 61.3085 ( -18.5862 67.9749 )
Norm@50keV : 3.123611E-03 ( -3.089896E-03 3.307260E-02) )
------------------------------------------------------------
Chi-Squared = 67.27502 using 59 PHA bins.
Reduced chi-squared = 1.223182 for 55 degrees of freedom
Null hypothesis probability = 0.124
Photon flux (15-150 keV) in 48.00 sec: 0.108411 ( -0.0214678 0.021943 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.5197e-07 ( -7.68283e-08 8.11243e-08 ) ergs/cm2
Peak spectrum fit using the pre-slew DRM
Power-law model
Time interval is from 33.000 sec. to 49.000 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.63268 ( -0.394616 0.421796 )
Norm@50keV : 1.236984E-03 ( -3.046923E-04 2.962493E-04) )
------------------------------------------------------------
Chi-Squared = 51.51709 using 59 PHA bins.
Reduced chi-squared = 0.9038087 for 57 degrees of freedom
Null hypothesis probability = 0.680
Photon flux (15-150 keV) in 16.00 sec: 0.160607 ( -0.036848 0.03694 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.84397e-07 ( -4.72832e-08 4.84464e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 33.000 sec. to 49.000 sec.
Parameters : value lower 90% higher 90%
Photon index: 0.928124 ( -1.95691 1.36004 )
Epeak [keV] : 78.7986 ( -20.4800 9921.20 )
Norm@50keV : 2.755596E-03 ( -2.755596E-03 2.023750E-02) )
------------------------------------------------------------
Chi-Squared = 50.81310 using 59 PHA bins.
but latest trial 2.02883 gives Chi-Squared = 1.60240
but latest trial 38.7126 gives Chi-Squared = 2.83443
Reduced chi-squared = 0.9073767 for 56 degrees of freedom
Null hypothesis probability = 0.671
Photon flux (15-150 keV) in 16.00 sec: 0.156063 ( -0.038188 0.037978 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.78712e-07 ( -4.82627e-08 4.9792e-08 ) ergs/cm2
Band function
Time interval is from 33.000 sec. to 49.000 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.944105 ( -9.05589 1.60057 )
beta : -8.27014 ( -1.72986 6.97498 )
Epeak [keV] : 79.3787 ( -79.2787 9920.62 )
Norm@50keV : 2.710270E-03 ( -2.710270E-03 2.032021E-02) )
------------------------------------------------------------
Chi-Squared = 50.81404 using 59 PHA bins.
Reduced chi-squared = 0.9238916 for 55 degrees of freedom
Null hypothesis probability = 0.635
Photon flux (15-150 keV) in 16.00 sec: 0.156091 ( -0.038238 0.038039 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.78542e-07 ( -4.81544e-08 4.99104e-08 ) ergs/cm2
Plot creation:
Thu Dec 13 22:46:30 EST 2007