batgrbproduct Analysis for Trigger=306778
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): Wed Mar 19 11:03:53 EDT 2008
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger306778/GCN5_download_cron
======================================================================
Trigger: 00306778 Segment: 000
BAT Trigger Time: 227622359.616 [s; MET]
Trigger Stop: 227622360.64 [s; MET]
UTC: 2008-03-19T12:25:56.961660 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 258.973352489113 Dec: 55.4098844023449 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 15.1
Image Trigger?: NO
Rate S/N Ratio: 69.3613725354393 [ if not an image trigger ]
Image S/N Ratio: 15.1
Flight Position: [ source = BAT ]
RA: 258.973352489113 Dec: 55.4098844023449 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 259.005713768135 Dec: 55.3925071492988 [deg; J2000]
{ 17h 16m 01.4s , +55d 23' 33.0" }
+/- 0.952661519588548 [arcmin] (estimated 90% radius based on SNR)
+/- 0.313891420461837 [arcmin] (formal 1-sigma fit error)
SNR: 32.5991338368315
RA = 17h 16m 1.4s (259.005714 deg.)
Dec = 55d 23' 33" (55.392507 deg.)
Angular difference between Flight and Ground position is 1.517456 arcmin
Partial Coding Fraction: 0.3046875 [ including projection effects ]
Duration
T90: 33.944000005722 +/- 8.88502944558435
Measured from: 0.23199999332428
to: 34.1759999990463 [s; relative to TRIGTIME]
T50: 7.71599999070168 +/- 0.501725039824458
Measured from: 2.08000001311302
to: 9.7960000038147 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 0.127999991178513
to: 1.12799999117851 [s; relative to TRIGTIME]
Total Fluence
Measured from: -0.328000009059906
to: 51.2199999988079 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 1.196555 1.957533 1.652060 0.444676
0.061939 0.065074 0.061356 0.055224 [error]
Peak 0.133473 0.218079 0.229293 0.067826
0.010841 0.013062 0.013726 0.011351 [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 4.12e-07 8.22e-07 1.27e-06 4.35e-06 3.56e-06 6.84e-06 erg/cm2
Error 3.27e-08 3.77e-08 6.04e-08 4.77e-07 1.50e-07 5.14e-07 erg/cm2
Peak flux Power-law 1.28e+00 1.61e+00 1.48e+00 2.37e+00 5.18e+00 6.75e+00 ph/cm2/s
Error 1.58e-01 1.21e-01 1.05e-01 3.60e-01 3.32e-01 4.54e-01 ph/cm2/s
Fluence Cutoff-PL 3.83e-07 8.39e-07 1.31e-06 2.92e-06 3.50e-06 5.40e-06 erg/cm2
Error 4.17e-08 4.19e-08 7.07e-08 8.01e-07 1.63e-07 7.82e-07 erg/cm2
Peak flux Cutoff-PL 1.20e+00 1.64e+00 1.53e+00 1.82e+00 5.14e+00 6.20e+00 ph/cm2/s
Error 1.98e-01 1.33e-01 1.35e-01 7.19e-01 3.36e-01 7.92e-01 ph/cm2/s
Fluence Band 3.80e-07 8.36e-07 1.31e-06 2.92e-06 3.50e-06 5.45e-06 erg/cm2
Error 4.13e-08 4.19e-08 7.06e-08 8.73e-07 1.63e-07 1.12e-06 erg/cm2
Peak flux Band 1.20e+00 1.64e+00 1.53e+00 1.82e+00 5.14e+00 6.20e+00 ph/cm2/s
Error 2.46e-01 1.33e-01 1.35e-01 7.18e-01 3.38e-01 7.92e-01 ph/cm2/s
=== Time-averaged spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.366 0.073 - - 7.09e-03 2.77e-04 52.845 57
CPL 1.064 0.305 171.3 764.2 9.77e-03 3.05e-03 49.757 0
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.124 0.109 - - 4.46e-02 2.78e-03 49.541 57
CPL 0.857 0.405 244.4 5000.0 5.90e-02 2.60e-02 48.396 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: 11.520000 sec.
T50 in the 50-300 keV band: 6.784000 sec.
=== Table of the duration information ==
Value tstart tstop
T100 51.548 -0.328 51.220
T90 33.944 0.232 34.176
T50 7.716 2.080 9.796
Peak 1.000 0.128 1.128
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
259.0057 +55.3925 0.0059 33.7 -101.5 5.3456 32.6 TRIG_00306778
------------------------------------------
Foreground time interval of the image:
-0.328 51.220 (delta_t = 51.548 [sec])
Background time interval of the image:
-119.616 -0.328 (delta_t = 119.288 [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 -0.328 sec. to 51.220 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.36604 ( -7.356572E-02 7.340026E-02) )
Norm@50keV : 7.093390E-03 ( -2.770456E-04 2.770503E-04) )
------------------------------------------------------------
Chi-Squared = 52.84520 using 59 PHA bins.
Reduced chi-squared = 0.9271088 for 57 degrees of freedom
Null hypothesis probability = 0.632
Photon flux (15-150 keV) in 51.55 sec: 0.857420 ( -0.036144 0.036248 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.55856e-06 ( -1.49278e-07 1.49964e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.328 sec. to 51.220 sec.
Parameters : value lower 90% higher 90%
Photon index: 1.06374 ( -0.318687 0.291426 )
Epeak [keV] : 171.303 ( -60.8394 1467.48 )
Norm@50keV : 9.765879E-03 ( -2.292239E-03 3.804349E-03) )
------------------------------------------------------------
Chi-Squared = 49.75720 using 59 PHA bins.
but latest trial 1.35494 gives Chi-Squared = 3.21504
but latest trial 7.217937E-03 gives Chi-Squared = 3.29064
Reduced chi-squared = 0.8885214 for 56 degrees of freedom
Null hypothesis probability = 0.709
Photon flux (15-150 keV) in 51.55 sec: 0.842299 ( -0.038696 0.038922 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.49929e-06 ( -1.63867e-07 1.61821e-07 ) ergs/cm2
Band function
Time interval is from -0.328 sec. to 51.220 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.874326 ( -0.424198 2.26960 )
beta : -1.53464 ( -8.46536 0.189266 )
Epeak [keV] : 109.574 ( -68.4700 3655.61 )
Norm@50keV : 1.254231E-02 ( -5.235313E-03 4.07017 )
------------------------------------------------------------
Chi-Squared = 49.58071 using 59 PHA bins.
Reduced chi-squared = 0.9014675 for 55 degrees of freedom
Null hypothesis probability = 0.681
Photon flux (15-150 keV) in 51.55 sec: 0.838744 ( -0.039509 0.040534 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.49648e-06 ( -1.63548e-07 1.62094e-07 ) ergs/cm2
Peak spectrum fit using the pre-slew DRM
Power-law model
Time interval is from 0.128 sec. to 1.128 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.12361 ( -0.109268 0.108538 )
Norm@50keV : 4.457359E-02 ( -2.779640E-03 2.778471E-03) )
------------------------------------------------------------
Chi-Squared = 49.54086 using 59 PHA bins.
Reduced chi-squared = 0.8691379 for 57 degrees of freedom
Null hypothesis probability = 0.748
Photon flux (15-150 keV) in 1.000 sec: 5.18270 ( -0.33194 0.33224 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.62568e-07 ( -3.1933e-08 3.2045e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.128 sec. to 1.128 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.856761 ( -0.463390 0.345854 )
Epeak [keV] : 244.386 ( -244.376 9755.61 )
Norm@50keV : 5.903245E-02 ( -1.636872E-02 3.556233E-02) )
------------------------------------------------------------
Chi-Squared = 48.39562 using 59 PHA bins.
Reduced chi-squared = 0.8642076 for 56 degrees of freedom
Null hypothesis probability = 0.755
Photon flux (15-150 keV) in 1.000 sec: 5.14466 ( -0.33752 0.33547 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.59106e-07 ( -3.3275e-08 3.2767e-08 ) ergs/cm2
Band function
Time interval is from 0.128 sec. to 1.128 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.863098 ( -0.339806 0.470761 )
beta : -9.31204 ( -2.269745E-04 0.687720 )
Epeak [keV] : 254.693 ( -120.445 9755.57 )
Norm@50keV : 5.832330E-02 ( -1.633480E-02 3.564968E-02) )
------------------------------------------------------------
Chi-Squared = 48.40679 using 59 PHA bins.
Reduced chi-squared = 0.8801235 for 55 degrees of freedom
Null hypothesis probability = 0.723
Photon flux (15-150 keV) in 1.000 sec: 5.14455 ( -0.33755 0.33754 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.58704e-07 ( -3.3158e-08 3.29e-08 ) ergs/cm2
Plot creation:
Wed Mar 19 11:09:45 EDT 2008