batgrbproduct Analysis for Trigger=205851
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 18:37:42 EST 2007
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger205851/SDC
======================================================================
Trigger: 00205851 Segment: 000
BAT Trigger Time: 167022369.344 [s; MET]
Trigger Stop: 167022370.368 [s; MET]
UTC: 2006-04-18T03:06:08.204500 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 236.419948391906 Dec: -3.64343384352562 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 10.8
Image Trigger?: NO
Rate S/N Ratio: 28.9309522829789 [ if not an image trigger ]
Image S/N Ratio: 10.8
Flight Position: [ source = BAT ]
RA: 236.419948391906 Dec: -3.64343384352562 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 236.43091747163 Dec: -3.64279709705034 [deg; J2000]
{ 15h 45m 43.4s , -03d 38' 34.1" }
+/- 0.972082890120811 [arcmin] (estimated 90% radius based on SNR)
+/- 0.419294733032042 [arcmin] (formal 1-sigma fit error)
SNR: 31.6727006116107
RA = 15h 45m 43.4s (236.430917 deg.)
Dec = -3d 38' 34" (-3.642797 deg.)
Angular difference between Flight and Ground position is 0.657925 arcmin
Partial Coding Fraction: 0.3046875 [ including projection effects ]
Duration
T90: 144 +/- 45.254833995939
Measured from: -63.3440000116825
to: 80.6559999883175 [s; relative to TRIGTIME]
T50: 16 +/- 16
Measured from: 0.65599998831749
to: 16.6559999883175 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 8.15599998831749
to: 9.15599998831749 [s; relative to TRIGTIME]
Total Fluence
Measured from: -95.3440000116825
to: 144.655999988317 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 4.355642 5.192431 3.560397 0.874701
0.133161 0.121193 0.105737 0.093252 [error]
Peak 1.383631 1.937348 1.538356 0.423878
0.047576 0.046904 0.042415 0.033516 [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 1.43e-06 2.29e-06 2.77e-06 6.55e-06 8.36e-06 1.30e-05 erg/cm2
Error 8.96e-08 7.97e-08 1.11e-07 6.11e-07 2.63e-07 6.64e-07 erg/cm2
Peak flux Power-law 8.85e-01 9.17e-01 6.70e-01 7.88e-01 2.78e+00 3.26e+00 ph/cm2/s
Error 5.79e-02 3.47e-02 2.28e-02 6.09e-02 9.46e-02 9.67e-02 ph/cm2/s
Fluence Cutoff-PL 1.38e-06 2.30e-06 2.79e-06 5.55e-06 8.29e-06 1.18e-05 erg/cm2
Error 1.18e-07 8.49e-08 9.05e-08 1.51e-06 3.02e-07 1.56e-06 erg/cm2
Peak flux Cutoff-PL 8.69e-01 9.18e-01 6.75e-01 7.64e-01 2.77e+00 3.21e+00 ph/cm2/s
Error 7.18e-02 3.55e-02 2.02e-02 1.16e-01 9.75e-02 1.60e-01 ph/cm2/s
Fluence Band 1.37e-06 2.30e-06 2.79e-06 5.53e-06 8.28e-06 1.18e-05 erg/cm2
Error 1.17e-07 1.06e-07 1.21e-07 1.51e-06 3.04e-07 1.56e-06 erg/cm2
Peak flux Band 8.75e-01 9.19e-01 6.70e-01 7.85e-01 2.77e+00 3.25e+00 ph/cm2/s
Error 6.80e-02 3.79e-02 2.27e-02 1.18e-01 7.70e-02 1.14e-01 ph/cm2/s
=== Time-averaged spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.726 0.062 - - 3.77e-03 1.15e-04 44.101 57
CPL 1.602 0.215 172.6 5000.0 4.30e-03 9.66e-04 43.320 56
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.451 0.059 - - 2.25e-02 6.69e-04 51.023 57
CPL 1.392 0.159 593.3 5000.0 2.39e-02 4.05e-03 51.009 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: 38.080000 sec.
T50 in the 50-300 keV band: 18.560000 sec.
=== Table of the duration information ==
Value tstart tstop
T100 240.000 -95.344 144.656
T90 144.000 -63.344 80.656
T50 16.000 0.656 16.656
Peak 1.000 8.156 9.156
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
236.4309 -3.6428 0.0061 31.2 95.0 8.7777 31.7 TRIG_00205851
------------------------------------------
Foreground time interval of the image:
-95.344 15.661 (delta_t = 111.005 [sec])
Background time interval of the image:
-239.344 -95.344 (delta_t = 144.000 [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 -95.344 sec. to 144.656 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.72620 ( -6.222963E-02 6.244838E-02) )
Norm@50keV : 3.770099E-03 ( -1.155201E-04 1.154274E-04) )
------------------------------------------------------------
Chi-Squared = 44.10128 using 59 PHA bins.
Reduced chi-squared = 0.7737066 for 57 degrees of freedom
Null hypothesis probability = 0.894
Photon flux (15-150 keV) in 240.0 sec: 0.505382 ( -0.017935 0.01805 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.36141e-06 ( -2.62512e-07 2.6316e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -95.344 sec. to 144.656 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.60174 ( -0.254660 0.176144 )
Epeak [keV] : 172.564 ( -172.554 9827.44 )
Norm@50keV : 4.304888E-03 ( -6.267009E-04 1.305082E-03) )
------------------------------------------------------------
Chi-Squared = 43.32019 using 59 PHA bins.
Reduced chi-squared = 0.7735748 for 56 degrees of freedom
Null hypothesis probability = 0.892
Photon flux (15-150 keV) in 240.0 sec: 0.499612 ( -0.020542 0.020598 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.28874e-06 ( -3.0588e-07 2.98896e-07 ) ergs/cm2
Band function
Time interval is from -95.344 sec. to 144.656 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.37534 ( -8.62466 3.50116 )
beta : -1.73746 ( -7.96586 0.360758 )
Epeak [keV] : 52.7873 ( -156.058 9843.84 )
Norm@50keV : 6.485014E-03 ( -7.154467E-04 7.41412 )
------------------------------------------------------------
Chi-Squared = 43.83020 using 59 PHA bins.
Reduced chi-squared = 0.7969127 for 55 degrees of freedom
Null hypothesis probability = 0.860
Photon flux (15-150 keV) in 240.0 sec: 0.499637 ( -0.020752 0.020833 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.27777e-06 ( -3.03792e-07 3.04656e-07 ) ergs/cm2
Peak spectrum fit using the pre-slew DRM
Power-law model
Time interval is from 0.656 sec. to 16.656 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.45129 ( -5.855656E-02 5.847836E-02) )
Norm@50keV : 2.252432E-02 ( -6.689075E-04 6.686747E-04) )
------------------------------------------------------------
Chi-Squared = 51.02284 using 59 PHA bins.
Reduced chi-squared = 0.8951376 for 57 degrees of freedom
Null hypothesis probability = 0.698
Photon flux (15-150 keV) in 16.00 sec: 2.77670 ( -0.09437 0.09481 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.4483e-06 ( -1.06464e-07 1.05744e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.656 sec. to 16.656 sec.
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.39227 ( -0.203772 0.114634 )
Epeak [keV] : 593.289 ( -593.279 9406.71 )
Norm@50keV : 2.391337E-02 ( -2.833866E-03 5.273458E-03) )
------------------------------------------------------------
Chi-Squared = 51.00862 using 59 PHA bins.
but latest trial 2.262191E-02 gives Chi-Squared = 6.877899E-03
Reduced chi-squared = 0.9108682 for 56 degrees of freedom
Null hypothesis probability = 0.664
Photon flux (15-150 keV) in 16.00 sec: 2.76966 ( -0.09681 0.09821 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.44851e-06 ( -1.06016e-07 1.06256e-07 ) ergs/cm2
Band function
Time interval is from 0.656 sec. to 16.656 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.945899 ( -9.05410 1.47619 )
beta : -1.45544 ( -8.54456 6.124103E-02) )
Epeak [keV] : 50.9282 ( -50.8282 877.661 )
Norm@50keV : 5.386234E-02 ( -3.198272E-02 96.9384 )
------------------------------------------------------------
Chi-Squared = 50.90052 using 59 PHA bins.
Reduced chi-squared = 0.9254639 for 55 degrees of freedom
Null hypothesis probability = 0.632
Photon flux (15-150 keV) in 16.00 sec: 2.76763 ( -0.05952 0.09449 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.44634e-06 ( -1.19808e-07 1.05296e-07 ) ergs/cm2
Plot creation:
Mon Dec 31 19:00:57 EST 2007