batgrbproduct Analysis for Trigger=307604
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): Thu Mar 27 03:37:25 EDT 2008
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger307604/SDC
======================================================================
Trigger: 00307604 Segment: 000
BAT Trigger Time: 228110960 [s; MET]
Trigger Stop: 228111024 [s; MET]
UTC: 2008-03-25T04:09:17.332080 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 277.894805295646 Dec: 36.5106329498597 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 7.46
Image Trigger?: YES
Rate S/N Ratio: 0 [ if not an image trigger ]
Image S/N Ratio: 7.46
Flight Position: [ source = BAT ]
RA: 277.894805295646 Dec: 36.5106329498597 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 277.906128054039 Dec: 36.5160719218339 [deg; J2000]
{ 18h 31m 37.5s , +36d 30' 57.9" }
+/- 1.99151586825735 [arcmin] (estimated 90% radius based on SNR)
+/- 0.940534442717483 [arcmin] (formal 1-sigma fit error)
SNR: 11.3687572294304
RA = 18h 31m 37.5s (277.906128 deg.)
Dec = 36d 30' 58" (36.516072 deg.)
Angular difference between Flight and Ground position is 0.636108 arcmin
Partial Coding Fraction: 0.1083984 [ including projection effects ]
Duration
T90: 128.432000011206 +/- 34.1860933668972
Measured from: -23.0719999969006
to: 105.360000014305 [s; relative to TRIGTIME]
T50: 64.244000017643 +/- 20.9614568271843
Measured from: -3.43999999761581
to: 60.8040000200272 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 38.0200000107288
to: 39.0200000107288 [s; relative to TRIGTIME]
Total Fluence
Measured from: -29.2960000038147
to: 170.456000000238 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 2.025062 2.284176 2.097104 0.411850
0.216503 0.198308 0.174946 0.155114 [error]
Peak 0.039701 0.056945 0.036026 0.034256
0.019711 0.017256 0.015755 0.013101 [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 7.97e-07 1.31e-06 1.63e-06 4.02e-06 4.87e-06 7.74e-06 erg/cm2
Error 1.38e-07 1.31e-07 1.78e-07 9.95e-07 4.36e-07 1.09e-06 erg/cm2
Peak flux Power-law 5.14e-01 4.59e-01 2.82e-01 2.63e-01 1.37e+00 1.52e+00 ph/cm2/s
Error 3.46e-01 1.96e-01 1.19e-01 2.23e-01 5.70e-01 5.74e-01 ph/cm2/s
Fluence Cutoff-PL 7.98e-07 1.31e-06 1.63e-06 4.00e-06 4.87e-06 7.71e-06 erg/cm2
Error 1.38e-07 1.31e-07 1.78e-07 9.89e-07 4.36e-07 1.08e-06 erg/cm2
Peak flux Cutoff-PL 3.78e-01 4.95e-01 3.25e-01 1.10e-01 1.28e+00 1.31e+00 ph/cm2/s
Error 3.94e-01 2.39e-01 1.63e-01 2.53e-01 5.99e-01 6.72e-01 ph/cm2/s
Fluence Band 7.94e-07 1.31e-06 1.63e-06 4.00e-06 4.87e-06 7.79e-06 erg/cm2
Error 6.91e-08 1.14e-07 1.42e-07 6.96e-07 4.31e-07 7.17e-07 erg/cm2
Peak flux Band 3.75e-01 5.05e-01 3.22e-01 1.52e-01 1.23e+00 1.39e+00 ph/cm2/s
Error 2.31e-01 1.52e-01 2.40e-01 5.86e-01 5.24e-01 0.00e+00 ph/cm2/s
=== Time-averaged spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.685 0.166 - - 2.63e-03 2.30e-04 50.639 57
CPL 1.683 0.167 9999.3 5000.0 2.63e-03 2.30e-04 50.646 56
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.704 0.649 - - 1.03e-02 3.78e-03 65.782 57
CPL 0.446 2.611 67.9 5000.0 3.94e-02 6.28e-01 65.339 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: 122.752000 sec.
T50 in the 50-300 keV band: 46.912000 sec.
=== Table of the duration information ==
Value tstart tstop
T100 199.752 -29.296 170.456
T90 128.432 -23.072 105.360
T50 64.244 -3.440 60.804
Peak 1.000 38.020 39.020
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
277.9061 +36.5161 0.0169 55.8 -165.3 5.2868 11.4 TRIG_00307604
------------------------------------------
Foreground time interval of the image:
-29.296 75.605 (delta_t = 104.901 [sec])
Background time interval of the image:
-320.195 -29.296 (delta_t = 290.899 [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 -29.296 sec. to 170.456 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.68483 ( -0.164816 0.166832 )
Norm@50keV : 2.630991E-03 ( -2.298283E-04 2.296062E-04) )
------------------------------------------------------------
Chi-Squared = 50.63945 using 59 PHA bins.
Reduced chi-squared = 0.8884113 for 57 degrees of freedom
Null hypothesis probability = 0.711
Photon flux (15-150 keV) in 199.8 sec: 0.347593 ( -0.034815 0.03518 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.87314e-06 ( -4.35064e-07 4.36123e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -29.296 sec. to 170.456 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.68308 ( -0.165885 0.167865 )
Epeak [keV] : 9999.31 ( -9999.30 0.689453 )
Norm@50keV : 2.633805E-03 ( -2.281459E-04 2.325701E-04) )
------------------------------------------------------------
Chi-Squared = 50.64553 using 59 PHA bins.
Reduced chi-squared = 0.9043844 for 56 degrees of freedom
Null hypothesis probability = 0.677
Photon flux (15-150 keV) in 199.8 sec: 0.347390 ( -0.034794 0.035162 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.87422e-06 ( -4.35384e-07 4.36263e-07 ) ergs/cm2
Band function
Time interval is from -29.296 sec. to 170.456 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.44081 ( -1.173973E-03 14.9988 )
beta : -1.66589 ( -0.166823 0.164828 )
Epeak [keV] : 11.3130 ( -11.2130 9988.69 )
Norm@50keV : 5.659341E-03 ( -3.123212E-02 3.117409E-02) )
------------------------------------------------------------
Chi-Squared = 50.67539 using 59 PHA bins.
Reduced chi-squared = 0.9213707 for 55 degrees of freedom
Null hypothesis probability = 0.640
Photon flux (15-150 keV) in 199.8 sec: 1.93753 ( -1.93753 691.519 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.86847e-06 ( -4.23956e-07 4.37442e-07 ) ergs/cm2
Peak spectrum fit using the pre-slew DRM
Power-law model
Time interval is from 38.020 sec. to 39.020 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.70366 ( -0.636981 0.660578 )
Norm@50keV : 1.027560E-02 ( -3.776968E-03 3.775684E-03) )
------------------------------------------------------------
Chi-Squared = 65.78226 using 59 PHA bins.
Reduced chi-squared = 1.154075 for 57 degrees of freedom
Null hypothesis probability = 0.199
Photon flux (15-150 keV) in 1.000 sec: 1.36650 ( -0.558483 0.58104 ) ph/cm2/s
Energy fluence (15-150 keV) : 9.51032e-08 ( -3.52201e-08 3.53948e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 38.020 sec. to 39.020 sec.
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.445651 ( -3.44565 1.77548 )
Epeak [keV] : 67.8744 ( -67.8644 9932.13 )
Norm@50keV : 3.940156E-02 ( -3.940156E-02 1.21601 )
------------------------------------------------------------
Chi-Squared = 65.33886 using 59 PHA bins.
but latest trial 1.35757 gives Chi-Squared = 2.75989
Reduced chi-squared = 1.166765 for 56 degrees of freedom
Null hypothesis probability = 0.184
Photon flux (15-150 keV) in 1.000 sec: 1.27843 ( -0.577789 0.6193 ) ph/cm2/s
Energy fluence (15-150 keV) : 9.14919e-08 ( -4.01462e-08 3.72501e-08 ) ergs/cm2
Band function
Time interval is from 38.020 sec. to 39.020 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : 0.629132 ( -10.6291 4.37087 )
beta : -2.56255 ( -7.43745 1.39190 )
Epeak [keV] : 56.4933 ( -56.3933 9943.51 )
Norm@50keV : 0.139192 ( -0.139192 75.1464 )
------------------------------------------------------------
Chi-Squared = 65.05443 using 59 PHA bins.
Reduced chi-squared = 1.182808 for 55 degrees of freedom
Null hypothesis probability = 0.166
Photon flux (15-150 keV) in 1.000 sec: 1.22508 ( -0.53958 0.63191 ) ph/cm2/s
Energy fluence (15-150 keV) : 9.11281e-08 ( -3.44907e-08 3.59379e-08 ) ergs/cm2
Plot creation:
Thu Mar 27 05:05:39 EDT 2008