batgrbproduct Analysis for Trigger=151486
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): Tue Jan 8 17:41:47 EST 2008
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger151486/SDC
======================================================================
Trigger: 00151486 Segment: 000
BAT Trigger Time: 146375368.832 [s; MET]
Trigger Stop: 146375370.88 [s; MET]
UTC: 2005-08-22T03:49:29.144560 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 51.0802641049472 Dec: -46.0231259929805 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 9.73
Image Trigger?: NO
Rate S/N Ratio: 7.41619848709566 [ if not an image trigger ]
Image S/N Ratio: 9.73
Flight Position: [ source = BAT ]
RA: 51.0802641049472 Dec: -46.0231259929805 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 51.1032488082184 Dec: -46.0270165266402 [deg; J2000]
{ 03h 24m 24.8s , -46d 01' 37.3" }
+/- 1.69053278354373 [arcmin] (estimated 90% radius based on SNR)
+/- 0.779653402013443 [arcmin] (formal 1-sigma fit error)
SNR: 14.36714199233
RA = 3h 24m 24.8s (51.103249 deg.)
Dec = -46d 1' 37" (-46.027017 deg.)
Angular difference between Flight and Ground position is 0.985599 arcmin
Partial Coding Fraction: 0.3710938 [ including projection effects ]
Duration
T90: 103.376000016928 +/- 16.3472248307154
Measured from: 1.21200001239777
to: 104.588000029325 [s; relative to TRIGTIME]
T50: 44.7880000174046 +/- 4.81547007815642
Measured from: 11.2400000095367
to: 56.0280000269413 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 47.5720000267029
to: 48.5720000267029 [s; relative to TRIGTIME]
Total Fluence
Measured from: -0.567999988794327
to: 133.688000023365 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 2.168091 1.872665 0.655451 0.325639
0.085055 0.088570 0.086172 0.092761 [error]
Peak 0.087617 0.107060 0.048178 0.001154
0.007813 0.008117 0.007418 0.007575 [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 8.16e-07 8.50e-07 6.25e-07 7.40e-07 2.58e-06 3.03e-06 erg/cm2
Error 7.65e-08 5.32e-08 8.02e-08 1.89e-07 1.76e-07 2.78e-07 erg/cm2
Peak flux Power-law 1.14e+00 8.03e-01 3.72e-01 2.42e-01 2.43e+00 2.56e+00 ph/cm2/s
Error 1.63e-01 7.70e-02 6.18e-02 7.71e-02 2.36e-01 2.45e-01 ph/cm2/s
Fluence Cutoff-PL 7.94e-07 8.77e-07 5.96e-07 3.76e-07 2.48e-06 2.64e-06 erg/cm2
Error 8.81e-08 7.01e-08 1.02e-07 3.89e-07 2.40e-07 4.99e-07 erg/cm2
Peak flux Cutoff-PL 1.06e+00 8.60e-01 3.69e-01 1.05e-01 2.36e+00 2.39e+00 ph/cm2/s
Error 1.90e-01 1.03e-01 7.01e-02 1.20e-01 2.50e-01 2.79e-01 ph/cm2/s
Fluence Band 7.63e-07 8.80e-07 5.79e-07 5.11e-07 2.44e-06 2.82e-06 erg/cm2
Error 1.03e-07 6.95e-08 1.07e-07 2.43e-07 2.72e-07 2.91e-07 erg/cm2
Peak flux Band 1.06e+00 8.60e-01 3.69e-01 1.05e-01 2.36e+00 2.39e+00 ph/cm2/s
Error 1.90e-01 1.03e-01 7.01e-02 1.20e-01 2.50e-01 2.79e-01 ph/cm2/s
=== Time-averaged spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 2.444 0.143 - - 1.95e-03 1.75e-04 57.200 57
CPL 1.895 0.000 7.4 0.0 4.10e-03 5.84e-04 56.601 0
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 2.108 0.191 - - 1.54e-02 1.91e-03 52.011 57
CPL 1.442 0.741 35.4 25.3 3.69e-02 5.53e-02 49.845 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: 57.536000 sec.
T50 in the 50-300 keV band: 43.264000 sec.
=== Table of the duration information ==
Value tstart tstop
T100 134.256 -0.568 133.688
T90 103.376 1.212 104.588
T50 44.788 11.240 56.028
Peak 1.000 47.572 48.572
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
51.1032 -46.0270 0.0134 41.9 165.6 1.7068 14.4 TRIG_00151486
------------------------------------------
Foreground time interval of the image:
-0.568 23.869 (delta_t = 24.437 [sec])
Background time interval of the image:
-119.832 -0.568 (delta_t = 119.264 [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 -0.568 sec. to 133.688 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.44353 ( -0.140666 0.145923 )
Norm@50keV : 1.947475E-03 ( -1.760294E-04 1.739555E-04) )
------------------------------------------------------------
Chi-Squared = 57.19979 using 59 PHA bins.
Reduced chi-squared = 1.003505 for 57 degrees of freedom
Null hypothesis probability = 0.468
Photon flux (15-150 keV) in 134.3 sec: 0.369726 ( -0.023623 0.023716 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.57755e-06 ( -1.74939e-07 1.77558e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.568 sec. to 133.688 sec.
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.89528 ( )
Epeak [keV] : 7.42239 ( )
Norm@50keV : 4.096808E-03 ( -5.561754E-04 6.109297E-04) )
------------------------------------------------------------
Chi-Squared = 56.60051 using 59 PHA bins.
but latest trial 4.252908E-03 gives Chi-Squared = 14.7689
Reduced chi-squared = 1.010723 for 56 degrees of freedom
Null hypothesis probability = 0.452
Photon flux (15-150 keV) in 134.3 sec: 0.369544 ( -0.023612 0.023704 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.47771e-06 ( -2.4495e-07 2.34259e-07 ) ergs/cm2
Band function
Time interval is from -0.568 sec. to 133.688 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.59776 ( -8.40224 2.92288 )
beta : -2.71728 ( -7.28272 0.346792 )
Epeak [keV] : 17.0727 ( -16.9727 9.50583 )
Norm@50keV : 6.453429E-03 ( -2.532505E-03 661.268 )
------------------------------------------------------------
Chi-Squared = 55.48208 using 59 PHA bins.
Reduced chi-squared = 1.008765 for 55 degrees of freedom
Null hypothesis probability = 0.456
Photon flux (15-150 keV) in 134.3 sec: 0.356006 ( -0.025867 0.030904 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.43673e-06 ( -2.05345e-07 3.39054e-07 ) ergs/cm2
Peak spectrum fit using the pre-slew DRM
Power-law model
Time interval is from 47.572 sec. to 48.572 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.10813 ( -0.186069 0.196277 )
Norm@50keV : 1.539244E-02 ( -1.928064E-03 1.885340E-03) )
------------------------------------------------------------
Chi-Squared = 52.01129 using 59 PHA bins.
Reduced chi-squared = 0.9124788 for 57 degrees of freedom
Null hypothesis probability = 0.662
Photon flux (15-150 keV) in 1.000 sec: 2.43136 ( -0.23614 0.2364 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.4313e-07 ( -1.5968e-08 1.6271e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 47.572 sec. to 48.572 sec.
Photon index: 1.44184 ( -0.945526 0.536223 )
Epeak [keV] : 35.4150 ( -35.4050 15.2543 )
Norm@50keV : 3.686399E-02 ( -1.944079E-02 9.123023E-02) )
------------------------------------------------------------
Chi-Squared = 49.84476 using 59 PHA bins.
but latest trial 2.23587 gives Chi-Squared = 118.671
but latest trial 64.1137 gives Chi-Squared = 3.06236
but latest trial 1.728831E-02 gives Chi-Squared = 4.89677
Reduced chi-squared = 0.8900851 for 56 degrees of freedom
Null hypothesis probability = 0.706
Photon flux (15-150 keV) in 1.000 sec: 2.36193 ( -0.24984 0.24929 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.34854e-07 ( -1.7914e-08 1.8703e-08 ) ergs/cm2
Band function
Time interval is from 47.572 sec. to 48.572 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.46180 ( -8.53820 0.820639 )
beta : -8.92727 ( -1.07273 6.90310 )
Epeak [keV] : 35.2974 ( -35.1974 18.8888 )
Norm@50keV : 3.591004E-02 ( -1.979709E-02 0.145818 )
------------------------------------------------------------
Chi-Squared = 49.84717 using 59 PHA bins.
Reduced chi-squared = 0.9063122 for 55 degrees of freedom
Null hypothesis probability = 0.671
Photon flux (15-150 keV) in 1.000 sec: 2.36211 ( -0.25005 0.24912 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.34883e-07 ( -1.811e-08 1.8511e-08 ) ergs/cm2
Plot creation:
Tue Jan 8 17:58:32 EST 2008