batgrbproduct Analysis for Trigger=147918
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 13:49:52 EST 2008
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger147918/SDC
======================================================================
Trigger: 00147918 Segment: 000
BAT Trigger Time: 144138704 [s; MET]
Trigger Stop: 144138768 [s; MET]
UTC: 2005-07-27T06:31:44.357120 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 238.256113857521 Dec: -21.7678288860753 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 7.98
Image Trigger?: YES
Rate S/N Ratio: 0 [ if not an image trigger ]
Image S/N Ratio: 7.98
Flight Position: [ source = BAT ]
RA: 238.256113857521 Dec: -21.7678288860753 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 238.293215697152 Dec: -21.7601480611204 [deg; J2000]
{ 15h 53m 10.4s , -21d 45' 36.5" }
+/- 2.5724150785818 [arcmin] (estimated 90% radius based on SNR)
+/- 1.17166020317414 [arcmin] (formal 1-sigma fit error)
SNR: 7.88709160241385
RA = 15h 53m 10.4s (238.293216 deg.)
Dec = -21d 45' 37" (-21.760148 deg.)
Angular difference between Flight and Ground position is 2.118172 arcmin
Partial Coding Fraction: 0.2617188 [ including projection effects ]
Duration
T90: 35.3000000119209 +/- 14.1357560654549
Measured from: 0.0679999887943268
to: 35.3680000007153 [s; relative to TRIGTIME]
T50: 13.8040000200272 +/- 10.2880932910703
Measured from: 14.5239999890327
to: 28.3280000090599 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 26.1719999909401
to: 27.1719999909401 [s; relative to TRIGTIME]
Total Fluence
Measured from: -3.21999999880791
to: 36.4480000138283 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.687125 0.100089 0.027461 0.011480
0.062039 0.059289 0.050530 0.043709 [error]
Peak 0.014473 0.034232 0.014919 0.006913
0.009939 0.009562 0.008512 0.006544 [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 2.50e-07 5.82e-08 6.95e-09 9.23e-10 3.16e-07 3.16e-07 erg/cm2
Error 4.38e-08 2.91e-08 8.29e-09 2.23e-09 6.51e-08 6.55e-08 erg/cm2
Peak flux Power-law 3.21e-01 2.07e-01 8.65e-02 4.93e-02 6.39e-01 6.63e-01 ph/cm2/s
Error 1.76e-01 8.73e-02 6.67e-02 8.18e-02 2.53e-01 2.65e-01 ph/cm2/s
Fluence Cutoff-PL 2.50e-07 5.52e-08 4.71e-09 6.89e-11 3.06e-07 3.15e-07 erg/cm2
Error 4.40e-08 2.63e-08 4.76e-08 6.85e-08 0.00e+00 0.00e+00 erg/cm2
Peak flux Cutoff-PL 3.21e-01 2.07e-01 8.64e-02 4.89e-02 6.39e-01 6.63e-01 ph/cm2/s
Error 1.76e-01 8.74e-02 6.67e-02 8.13e-02 2.53e-01 2.64e-01 ph/cm2/s
Fluence Band 2.47e-07 5.81e-08 7.00e-09 9.36e-10 3.14e-07 3.14e-07 erg/cm2
Error 4.32e-08 1.52e-08 1.46e-08 2.86e-10 5.71e-08 5.69e-07 erg/cm2
Peak flux Band 3.13e-01 2.15e-01 8.40e-02 4.34e-02 6.35e-01 6.56e-01 ph/cm2/s
Error 1.65e-01 1.04e-01 6.55e-02 5.51e-02 2.52e-01 2.66e-01 ph/cm2/s
=== Time-averaged spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 4.856 0.917 - - 1.88e-04 1.71e-04 50.447 57
CPL 1.884 0.898 0.8 4.0 6.72e-02 4.86e+02 50.042 0
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 2.259 0.968 - - 3.74e-03 2.23e-03 58.365 57
CPL 1.993 0.348 1.3 0.0 5.14e-03 2.93e-03 58.448 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 39.668 -3.220 36.448
T90 35.300 0.068 35.368
T50 13.804 14.524 28.328
Peak 1.000 26.172 27.172
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
238.2932 -21.7601 0.0245 34.6 57.3 0.9531 7.9 TRIG_00147918
------------------------------------------
Foreground time interval of the image:
-3.220 36.448 (delta_t = 39.668 [sec])
Background time interval of the image:
-299.000 -3.220 (delta_t = 295.780 [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 -3.220 sec. to 36.448 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 4.85567 ( -0.622492 1.21247 )
Norm@50keV : 1.875773E-04 ( -1.875773E-04 1.546634E-04) )
------------------------------------------------------------
Chi-Squared = 50.44669 using 59 PHA bins.
Reduced chi-squared = 0.8850296 for 57 degrees of freedom
Null hypothesis probability = 0.718
Photon flux (15-150 keV) in 39.67 sec: 0.250354 ( -0.0448 0.044879 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.16289e-07 ( -6.3501e-08 6.67495e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -3.220 sec. to 36.448 sec.
Photon index: 1.88381 ( -0.638750 1.15785 )
Epeak [keV] : 0.751451 ( -0.555074 7.47452 )
Norm@50keV : 6.724685E-02 ( -6.724685E-02 971.701 )
------------------------------------------------------------
Chi-Squared = 50.04182 using 59 PHA bins.
but latest trial 1.24506 gives Chi-Squared = 6.639862E-02
but latest trial -0.732063 gives Chi-Squared = 0.00000
but latest trial 8.22597 gives Chi-Squared = 0.342190
Reduced chi-squared = 0.8936039 for 56 degrees of freedom
Null hypothesis probability = 0.699
Photon flux (15-150 keV) in 39.67 sec: 0.248949 ( -0.04383 0.044186 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.05741e-07 ( -5.89587e-08 3.63389e-08 ) ergs/cm2
Band function
Time interval is from -3.220 sec. to 36.448 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.50431 ( -0.614033 0.885931 )
beta : -3.64954 ( -1.02903 14.2002 )
Epeak [keV] : 12.9567 ( -12.8567 9987.04 )
Norm@50keV : 5.832927E-03 ( -1.466481E-02 2.364352E-02) )
------------------------------------------------------------
Chi-Squared = 82.84699 using 59 PHA bins.
Reduced chi-squared = 1.506309 for 55 degrees of freedom
Null hypothesis probability = 8.970E-03
Photon flux (15-150 keV) in 39.67 sec: 0.250601 ( -0.022374 0.890629 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.13723e-07 ( -5.93911e-08 5.47791e-08 ) ergs/cm2
Peak spectrum fit using the pre-slew DRM
Power-law model
Time interval is from 26.172 sec. to 27.172 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.25865 ( -0.798554 1.13815 )
Norm@50keV : 3.740189E-03 ( -2.336768E-03 2.121667E-03) )
------------------------------------------------------------
Chi-Squared = 58.36474 using 59 PHA bins.
Reduced chi-squared = 1.023943 for 57 degrees of freedom
Null hypothesis probability = 0.425
Photon flux (15-150 keV) in 1.000 sec: 0.638929 ( -0.253399 0.253454 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.5491e-08 ( -1.67738e-08 1.84128e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 26.172 sec. to 27.172 sec.
Parameters : value lower 90% higher 90%
Photon index: 1.99306 ( -0.382739 0.312683 )
Epeak [keV] : 1.28840 ( )
Norm@50keV : 5.144680E-03 ( -3.567106E-03 2.297514E-03) )
------------------------------------------------------------
Chi-Squared = 58.44845 using 59 PHA bins.
but latest trial 1.61032 gives Chi-Squared = 10.1559
but latest trial -39.4304 gives Chi-Squared = 10.0557
Reduced chi-squared = 1.043722 for 56 degrees of freedom
Null hypothesis probability = 0.386
Photon flux (15-150 keV) in 1.000 sec: 0.638684 ( -0.253303 0.253369 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.54895e-08 ( -1.67958e-08 1.84154e-08 ) ergs/cm2
Band function
Time interval is from 26.172 sec. to 27.172 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.91520 ( -0.418606 0.934383 )
beta : -9.27709 ( -7.73097 0.807479 )
Epeak [keV] : 11.6333 ( -11.3251 9988.58 )
Norm@50keV : 5.716562E-03 ( -6.125515E-03 0.781119 )
------------------------------------------------------------
Chi-Squared = 58.48044 using 59 PHA bins.
Reduced chi-squared = 1.063281 for 55 degrees of freedom
Null hypothesis probability = 0.349
Photon flux (15-150 keV) in 1.000 sec: 0.634853 ( -0.251365 0.252285 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.1769e-08 ( -1.30853e-08 1.28043e-08 ) ergs/cm2
Plot creation:
Tue Jan 8 14:05:19 EST 2008