batgrbproduct Analysis for Trigger=208275
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 21:58:40 EST 2007
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger208275/GCN5_download_cron
======================================================================
Trigger: 00208275 Segment: 000
BAT Trigger Time: 168283482.176 [s; MET]
Trigger Stop: 168283482.624 [s; MET]
UTC: 2006-05-02T17:24:41.007100 [includes UTCF correction]
Where From?: (*SHORT BURST*) Expanded to TRIGTIME - 64 ms to TRIGTIME + 320 ms
BAT
RA: 278.935719107924 Dec: 52.6321691479945 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 11.47
Image Trigger?: NO
Rate S/N Ratio: 32.9696830436691 [ if not an image trigger ]
Image S/N Ratio: 11.47
Flight Position: [ source = BAT ]
RA: 278.935719107924 Dec: 52.6321691479945 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 278.964392202846 Dec: 52.6273406168922 [deg; J2000]
{ 18h 35m 51.5s , +52d 37' 38.4" }
+/- 1.76760948588134 [arcmin] (estimated 90% radius based on SNR)
+/- 0.660978681590997 [arcmin] (formal 1-sigma fit error)
SNR: 13.4806038482242
RA = 18h 35m 51.5s (278.964392 deg.)
Dec = 52d 37' 38" (52.627341 deg.)
Angular difference between Flight and Ground position is 1.083655 arcmin
Partial Coding Fraction: 0.921875 [ including projection effects ]
Duration
T90: 0.143999993801117 +/- 0.0357770935043183
Measured from: 0.0239999890327454
to: 0.167999982833862 [s; relative to TRIGTIME]
T50: 0.0479999780654907 +/- 0.0160000026226044
Measured from: 0.0399999916553497
to: 0.0879999697208405 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: -0.388000011444092
to: 0.611999988555908 [s; relative to TRIGTIME]
Total Fluence
Measured from: 0.0239999890327454
to: 0.184000015258789 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.008610 0.024807 0.024583 0.007125
0.002472 0.002709 0.002684 0.002167 [error]
Peak 0.009100 0.024980 0.025072 0.007380
0.002528 0.002787 0.002747 0.002224 [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 3.58e-09 8.80e-09 1.73e-08 8.41e-08 4.67e-08 1.00e-07 erg/cm2
Error 8.40e-10 1.28e-09 2.30e-09 2.52e-08 6.07e-09 0.00e+00 erg/cm2
Peak flux Power-law 6.66e-01 8.94e-01 8.82e-01 1.56e+00 2.95e+00 4.01e+00 ph/cm2/s
Error 1.59e-01 1.34e-01 1.14e-01 4.19e-01 3.69e-01 5.22e-01 ph/cm2/s
Fluence Cutoff-PL 2.71e-09 9.85e-09 1.97e-08 2.18e-08 4.44e-08 4.58e-08 erg/cm2
Error 1.02e-09 1.64e-09 3.02e-09 2.87e-08 6.70e-09 0.00e+00 erg/cm2
Peak flux Cutoff-PL 5.08e-01 9.73e-01 1.01e+00 5.99e-01 2.87e+00 3.09e+00 ph/cm2/s
Error 1.94e-01 1.63e-01 1.56e-01 4.91e-01 3.79e-01 5.96e-01 ph/cm2/s
Fluence Band 2.54e-09 1.02e-08 1.89e-08 4.46e-08 4.45e-08 4.78e-08 erg/cm2
Error 1.26e-09 1.64e-09 2.98e-09 2.31e-08 6.33e-09 0.00e+00 erg/cm2
Peak flux Band 0.00e+00 0.00e+00 0.00e+00 0.00e+00 0.00e+00 0.00e+00 ph/cm2/s
Error 0.00e+00 0.00e+00 0.00e+00 0.00e+00 0.00e+00 0.00e+00 ph/cm2/s
=== Time-averaged spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.024 0.197 - - 2.72e-02 3.36e-03 47.365 57
CPL -0.246 1.123 97.5 77.3 1.06e-01 1.77e-01 42.044 56
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.019 0.198 - - 2.56e-02 3.14e-03 47.267 57
CPL -0.156 1.096 102.0 101.8 8.95e-02 1.43e-01 42.552 56
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: 0.128000 sec.
T50 in the 50-300 keV band: 0.064000 sec.
=== Table of the duration information ==
Value tstart tstop
T100 0.160 0.024 0.184
T90 0.144 0.024 0.168
T50 0.048 0.040 0.088
Peak 1.000 -0.388 0.612
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
278.9644 +52.6273 0.0143 23.2 -2.3 0.0673 13.5 TRIG_00208275
------------------------------------------
Foreground time interval of the image:
-0.040 0.120 (delta_t = 0.160 [sec])
Background time interval of the image:
-239.240 -0.040 (delta_t = 239.200 [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 -0.040 sec. to 0.120 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.02377 ( -0.200394 0.193444 )
Norm@50keV : 2.724655E-02 ( -3.361298E-03 3.350206E-03) )
------------------------------------------------------------
Chi-Squared = 47.36457 using 59 PHA bins.
Reduced chi-squared = 0.8309574 for 57 degrees of freedom
Null hypothesis probability = 0.815
Photon flux (15-150 keV) in 0.1600 sec: 3.14126 ( -0.39469 0.39551 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.67312e-08 ( -6.03376e-09 6.10608e-09 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.040 sec. to 0.120 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.246171 ( -1.27643 0.968626 )
Epeak [keV] : 97.5459 ( -24.6801 130.010 )
Norm@50keV : 0.106385 ( -6.787796E-02 0.286352 )
------------------------------------------------------------
Chi-Squared = 42.04450 using 59 PHA bins.
Reduced chi-squared = 0.7507946 for 56 degrees of freedom
Null hypothesis probability = 0.917
Photon flux (15-150 keV) in 0.1600 sec: 3.05536 ( -0.40505 0.40375 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.43816e-08 ( -6.72752e-09 6.66832e-09 ) ergs/cm2
Band function
Time interval is from -0.040 sec. to 0.120 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.844916 ( -10.6665 4.33197 )
beta : -1.02378 ( -8.22173 0.658213 )
Epeak [keV] : 56.5528 ( -79.4627 9920.43 )
Norm@50keV : 4.449632E-02 ( -0.122350 506.460 )
------------------------------------------------------------
Chi-Squared = 47.36457 using 59 PHA bins.
Reduced chi-squared = 0.8611740 for 55 degrees of freedom
Null hypothesis probability = 0.758
Photon flux (15-150 keV) in 0.1600 sec: 3.02526 ( -0.40279 0.3798 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.44976e-08 ( -6.28416e-09 6.37728e-09 ) ergs/cm2
Peak spectrum fit using the pre-slew DRM
Power-law model
Time interval is from -0.040 sec. to 0.136 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.01936 ( -0.201286 0.194301 )
Norm@50keV : 2.561557E-02 ( -3.143614E-03 3.133224E-03) )
------------------------------------------------------------
Chi-Squared = 47.26699 using 59 PHA bins.
Reduced chi-squared = 0.8292455 for 57 degrees of freedom
Null hypothesis probability = 0.818
Photon flux (15-150 keV) in 0.1760 sec: 2.95255 ( -0.36894 0.36946 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.84473e-08 ( -6.28285e-09 6.26701e-09 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.040 sec. to 0.136 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.155598 ( -1.24707 0.945345 )
Epeak [keV] : 102.023 ( -27.4346 176.134 )
Norm@50keV : 8.945083E-02 ( -5.605596E-02 0.229111 )
------------------------------------------------------------
Chi-Squared = 42.55204 using 59 PHA bins.
Reduced chi-squared = 0.7598578 for 56 degrees of freedom
Null hypothesis probability = 0.907
Photon flux (15-150 keV) in 0.1760 sec: 2.87347 ( -0.37946 0.37778 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.6234e-08 ( -6.99406e-09 6.78022e-09 ) ergs/cm2
Band function
Time interval is from -0.040 sec. to 0.136 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.827865 ( -12.9622 2.03647 )
beta : -1.01936 ( -0.308071 0.315361 )
Epeak [keV] : 63.3629 ( )
Norm@50keV : 4.194120E-02 ( )
------------------------------------------------------------
Chi-Squared = 47.26699 using 59 PHA bins.
Reduced chi-squared = 0.8593999 for 55 degrees of freedom
Null hypothesis probability = 0.761
Photon flux (15-150 keV) in 0.1760 sec: ( ) ph/cm2/s
Energy fluence (15-150 keV) : 0 ( 0 0 ) ergs/cm2
Plot creation:
Mon Dec 31 22:28:16 EST 2007