batgrbproduct Analysis for Trigger=310219
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): Sun Apr 27 04:47:57 EDT 2008
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger310219/GCN5_download_cron
======================================================================
Trigger: 00310219 Segment: 000
BAT Trigger Time: 230909005.696 [s; MET]
Trigger Stop: 230909005.76 [s; MET]
UTC: 2008-04-26T13:23:22.949980 [includes UTCF correction]
Where From?: (*SHORT BURST*) TDRSS scaled map message
BAT
RA: 26.5741933788889 Dec: 69.4917855038209 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 8.32
Image Trigger?: NO
Rate S/N Ratio: 25.2586618806302 [ if not an image trigger ]
Image S/N Ratio: 8.32
Flight Position: [ source = BAT ]
RA: 26.5741933788889 Dec: 69.4917855038209 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 26.5099554428146 Dec: 69.468998136619 [deg; J2000]
{ 01h 46m 02.4s , +69d 28' 08.4" }
+/- 1.09831464232061 [arcmin] (estimated 90% radius based on SNR)
+/- 0.342726255384978 [arcmin] (formal 1-sigma fit error)
SNR: 26.6034079995132
RA = 1h 46m 2.4s (26.509955 deg.)
Dec = 69d 28' 8" (69.468998 deg.)
Angular difference between Flight and Ground position is 1.922144 arcmin
Partial Coding Fraction: 0.4335938 [ including projection effects ]
Duration
T90: 1.72000002861023 +/- 0.370297183277761
Measured from: -0.0240000188350677
to: 1.69600000977516 [s; relative to TRIGTIME]
T50: 0.608000010251999 +/- 0.127121971514403
Measured from: 0.143999993801117
to: 0.752000004053116 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: -0.0840000212192535
to: 0.915999978780746 [s; relative to TRIGTIME]
Total Fluence
Measured from: -0.148000001907349
to: 2.08799999952316 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.253049 0.253750 0.150098 0.003799
0.014086 0.014165 0.011565 0.008591 [error]
Peak 0.192318 0.209399 0.119540 -0.001280
0.010610 0.011173 0.008878 0.005966 [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 8.06e-08 1.11e-07 1.13e-07 2.10e-07 3.72e-07 5.21e-07 erg/cm2
Error 8.52e-09 7.25e-09 1.15e-08 4.42e-08 2.65e-08 5.50e-08 erg/cm2
Peak flux Power-law 2.12e+00 1.59e+00 7.89e-01 5.60e-01 4.76e+00 5.06e+00 ph/cm2/s
Error 2.11e-01 1.01e-01 7.40e-02 1.02e-01 3.13e-01 3.20e-01 ph/cm2/s
Fluence Cutoff-PL 7.89e-08 1.13e-07 1.14e-07 1.62e-07 3.68e-07 4.63e-07 erg/cm2
Error 9.89e-09 8.84e-09 8.96e-09 8.51e-08 2.91e-08 9.63e-08 erg/cm2
Peak flux Cutoff-PL 1.94e+00 1.69e+00 8.11e-01 2.81e-01 4.64e+00 4.73e+00 ph/cm2/s
Error 2.48e-01 1.29e-01 8.25e-02 1.51e-01 3.26e-01 3.62e-01 ph/cm2/s
Fluence Band 8.00e-08 1.11e-07 1.13e-07 2.10e-07 3.72e-07 5.14e-07 erg/cm2
Error 5.17e-09 7.21e-09 7.30e-09 3.10e-08 2.40e-08 3.33e-08 erg/cm2
Peak flux Band 1.95e+00 1.69e+00 8.10e-01 3.19e-01 4.64e+00 4.80e+00 ph/cm2/s
Error 2.47e-01 1.31e-01 8.90e-02 2.34e-01 3.20e-01 3.94e-01 ph/cm2/s
=== Time-averaged spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.975 0.125 - - 1.81e-02 1.33e-03 45.861 57
CPL 1.820 0.424 54.9 4991.1 2.18e-02 1.26e-02 45.531 0
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 2.007 0.115 - - 3.16e-02 2.27e-03 68.890 57
CPL 1.382 0.496 45.4 11.6 6.88e-02 4.60e-02 63.500 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: 1.280000 sec.
T50 in the 50-300 keV band: 0.448000 sec.
=== Table of the duration information ==
Value tstart tstop
T100 2.236 -0.148 2.088
T90 1.720 -0.024 1.696
T50 0.608 0.144 0.752
Peak 1.000 -0.084 0.916
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
26.5100 +69.4690 0.0072 29.7 -98.7 0.6989 26.6 TRIG_00310219
------------------------------------------
Foreground time interval of the image:
0.108 2.344 (delta_t = 2.236 [sec])
Background time interval of the image:
-239.440 -82.720 (delta_t = 156.720 [sec])
-81.440 -72.260 (delta_t = 9.180 [sec])
-71.440 0.108 (delta_t = 71.548 [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 0.108 sec. to 2.344 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.97457 ( -0.123649 0.126864 )
Norm@50keV : 1.806513E-02 ( -1.336500E-03 1.318803E-03) )
------------------------------------------------------------
Chi-Squared = 45.86073 using 59 PHA bins.
Reduced chi-squared = 0.8045741 for 57 degrees of freedom
Null hypothesis probability = 0.855
Photon flux (15-150 keV) in 2.236 sec: 2.67858 ( -0.18221 0.18292 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.72129e-07 ( -2.64496e-08 2.64787e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.108 sec. to 2.344 sec.
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.81975 ( -0.495436 0.353114 )
Epeak [keV] : 54.8658 ( -36.9779 9945.13 )
Norm@50keV : 2.182052E-02 ( -7.714164E-03 1.749067E-02) )
------------------------------------------------------------
Chi-Squared = 45.53086 using 59 PHA bins.
but latest trial 17.8879 gives Chi-Squared = 0.437725
Reduced chi-squared = 0.8130511 for 56 degrees of freedom
Null hypothesis probability = 0.840
Photon flux (15-150 keV) in 2.236 sec: 2.65646 ( -0.19244 0.18706 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.67726e-07 ( -2.89853e-08 2.92446e-08 ) ergs/cm2
Band function
Time interval is from 0.108 sec. to 2.344 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.82028 ( -8.17972 0.495538 )
beta : -7.95798 ( -2.04202 6.09935 )
Epeak [keV] : 55.1224 ( -55.0224 9944.88 )
Norm@50keV : 2.178745E-02 ( -4.893893E-03 1.751756E-02) )
------------------------------------------------------------
Chi-Squared = 45.53071 using 59 PHA bins.
Reduced chi-squared = 0.8278311 for 55 degrees of freedom
Null hypothesis probability = 0.815
Photon flux (15-150 keV) in 2.236 sec: 2.65655 ( -0.19266 0.19267 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.71824e-07 ( -2.40258e-08 2.40303e-08 ) ergs/cm2
Peak spectrum fit using the pre-slew DRM
Power-law model
Time interval is from 0.172 sec. to 1.172 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.00709 ( -0.113235 0.116218 )
Norm@50keV : 3.162327E-02 ( -2.285216E-03 2.259474E-03) )
------------------------------------------------------------
Chi-Squared = 68.89033 using 59 PHA bins.
Reduced chi-squared = 1.208602 for 57 degrees of freedom
Null hypothesis probability = 0.134
Photon flux (15-150 keV) in 1.000 sec: 4.75904 ( -0.3129 0.3135 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.91589e-07 ( -1.9946e-08 2.0317e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.172 sec. to 1.172 sec.
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.38201 ( -0.524406 0.468135 )
Epeak [keV] : 45.3592 ( -13.3652 9.89989 )
Norm@50keV : 6.884961E-02 ( -2.985603E-02 6.222822E-02) )
------------------------------------------------------------
Chi-Squared = 63.50032 using 59 PHA bins.
but latest trial 62.2823 gives Chi-Squared = 4.87543
Reduced chi-squared = 1.133934 for 56 degrees of freedom
Null hypothesis probability = 0.229
Photon flux (15-150 keV) in 1.000 sec: 4.63560 ( -0.32613 0.32597 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.79832e-07 ( -2.1763e-08 2.2164e-08 ) ergs/cm2
Band function
Time interval is from 0.172 sec. to 1.172 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.34065 ( -0.496304 2.81060 )
beta : -3.27400 ( -7.02361 0.922515 )
Epeak [keV] : 45.9777 ( -20.7116 13.6483 )
Norm@50keV : 7.182245E-02 ( -3.097386E-02 84.3369 )
------------------------------------------------------------
Chi-Squared = 63.49684 using 59 PHA bins.
Reduced chi-squared = 1.154488 for 55 degrees of freedom
Null hypothesis probability = 0.202
Photon flux (15-150 keV) in 1.000 sec: 4.63694 ( -0.31578 0.32413 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.79854e-07 ( -2.1846e-08 2.1677e-08 ) ergs/cm2
Plot creation:
Sun Apr 27 05:16:29 EDT 2008