batgrbproduct Analysis for Trigger=431764
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 batgrbproduct analysis is using the flight position for the mask-weighting calculation.
- 4) This page will be updated for up to 10 downlinks after the trigger.
======================================================================
BAT GRB EVENT DATA PROCESSING REPORT
Process Script Ver: batgrbproduct v2.46
Process Start Time (local time): Mon Aug 16 13:46:57 EDT 2010
Host Name: gcn5
Current Working Dir: /local/data/raid16/prebascript_archive/trigger431764/GCN5_download_cron
======================================================================
Trigger: 00431764 Segment: 000
BAT Trigger Time: 303611877.44 [s; MET]
Trigger Stop: 303611878.464 [s; MET]
UTC: 2010-08-16T00:37:51.355600 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 351.740552447025 Dec: 26.5605486062231 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 22.91
Image Trigger?: NO
Rate S/N Ratio: 132.064378240311 [ if not an image trigger ]
Image S/N Ratio: 22.91
Flight Position: [ source = BAT ]
RA: 351.740552447025 Dec: 26.5605486062231 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 351.73791392561 Dec: 26.567892982919 [deg; J2000]
{ 23h 26m 57.1s , +26d 34' 04.4" }
+/- 0.790456364981073 [arcmin] (estimated 90% radius based on SNR)
+/- 0.222515439603904 [arcmin] (formal 1-sigma fit error)
SNR: 42.5605364192621
Angular difference between Flight and Ground position is 0.462854 arcmin
Partial Coding Fraction: 0.3398438 [ including projection effects ]
Duration
T90: 2.87199991941452 +/- 0.621173085986678
Measured from: -0.307999849319458
to: 2.56400007009506 [s; relative to TRIGTIME]
T50: 1.0239999294281 +/- 0.0688186099521425
Measured from: 0.15200012922287
to: 1.17600005865097 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 0.10400003194809
to: 1.10400003194809 [s; relative to TRIGTIME]
Total Fluence
Measured from: -0.708000004291534
to: 4.51999998092651 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.525766 0.940751 0.973157 0.253276
0.024475 0.028302 0.027960 0.019798 [error]
Peak 0.230515 0.470063 0.504144 0.136192
0.013165 0.017005 0.017565 0.011384 [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 1.80e-07 4.07e-07 7.26e-07 3.05e-06 1.98e-06 4.37e-06 erg/cm2
Error 1.18e-08 1.60e-08 2.68e-08 2.54e-07 6.92e-08 2.68e-07 erg/cm2
Peak flux Power-law 2.49e+00 3.31e+00 3.23e+00 5.66e+00 1.09e+01 1.47e+01 ph/cm2/s
Error 1.66e-01 1.40e-01 1.33e-01 4.70e-01 4.01e-01 6.02e-01 ph/cm2/s
Fluence Cutoff-PL 1.61e-07 4.18e-07 7.64e-07 1.83e-06 1.95e-06 3.17e-06 erg/cm2
Error 1.50e-08 1.76e-08 3.33e-08 4.76e-07 7.21e-08 4.72e-07 erg/cm2
Peak flux Cutoff-PL 2.19e+00 3.48e+00 3.50e+00 3.24e+00 1.08e+01 1.24e+01 ph/cm2/s
Error 1.98e-01 1.62e-01 1.69e-01 7.64e-01 0.00e+00 0.00e+00 ph/cm2/s
Fluence Band 0.00e+00 0.00e+00 0.00e+00 0.00e+00 0.00e+00 0.00e+00 erg/cm2
Error 0.00e+00 0.00e+00 0.00e+00 0.00e+00 0.00e+00 0.00e+00 erg/cm2
Peak flux Band 1.27e+01 0.00e+00 0.00e+00 0.00e+00 0.00e+00 0.00e+00 ph/cm2/s
Error 0.00e+00 0.00e+00 0.00e+00 0.00e+00 0.00e+00 0.00e+00 ph/cm2/s
=== Time-averaged spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.165 0.057 - - 3.70e-02 1.22e-03 61.720 57
CPL 0.731 0.235 170.7 79.7 5.73e-02 1.34e-02 50.790 56
The chi2 of BB fit is which shows a significant improvement in the fit over a PL.
Check the BB fit.
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.032 0.058 - - 9.44e-02 3.45e-03 76.800 57
CPL 0.448 0.240 147.8 44.0 1.78e-01 4.54e-02 57.020 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: 1.856000 sec.
T50 in the 50-300 keV band: 0.960000 sec.
=== Table of the duration information ==
Value tstart tstop
T100 5.228 -0.708 4.520
T90 2.872 -0.308 2.564
T50 1.024 0.152 1.176
Peak 1.000 0.104 1.104
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
351.7379 +26.5679 0.0045 32.6 59.4 2.7838 42.6 TRIG_00431764
------------------------------------------
Foreground time interval of the image:
-0.708 4.520 (delta_t = 5.228 [sec])
Background time interval of the image:
-119.440 -0.708 (delta_t = 118.732 [sec])
Lightcurves
Notes:
- 1) All plots contain as much data as has been downloaded to date.
- 2) The mask-weighted light curves are using the flight position.
- 3) Multiple plots of different time binning/intervals are shown to cover all scenarios of short/long GRBs, rate/image triggers, and real/false positives.
- 4) 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.
- 5) 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.
- 6) 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.
- 4) For short bursts (T90<1sec), the specrtum is also fit with Blackbody, OTTB, and Double Blackbody.
Time averaged spectrum fit using the pre-slew DRM
Power-law model
Time interval is from -0.708 sec. to 4.520 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.16492 ( -0.0568394 0.0566055 )
Norm@50keV : 3.69562E-02 ( -0.00121647 0.00121582 )
------------------------------------------------------------
# Chi-Squared = 61.72 using 59 PHA bins.
# Reduced chi-squared = 1.083 for 57 degrees of freedom
# Null hypothesis probability = 3.113090e-01
Photon flux (15-150 keV) in 5.228 sec: 4.31768 ( -0.14907 0.149247 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.98012e-06 ( -6.91638e-08 6.92579e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.708 sec. to 4.520 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.730517 ( -0.241612 0.229347 )
Epeak [keV] : 170.706 ( -40.5766 118.844 )
Norm@50keV : 5.73066E-02 ( -0.0115524 0.0152376 )
------------------------------------------------------------
# Chi-Squared = 50.79 using 59 PHA bins.
# Reduced chi-squared = 0.9070 for 56 degrees of freedom
# Null hypothesis probability = 6.718000e-01
Photon flux (15-150 keV) in 5.228 sec: 4.23300 ( ) ph/cm2/s
Energy fluence (15-150 keV) : 1.95036e-06 ( -7.22353e-08 7.19268e-08 ) ergs/cm2
Band function
Time interval is from -0.708 sec. to 4.520 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.730560 ( -0.212813 0.166625 )
beta : -10.00000 ( 3.15472e+14 3.15472e+14 )
Epeak [keV] : 170.698 ( -40.589 118.816 )
Norm@50keV : 5.73011E-02 ( -0.0115504 0.0152454 )
------------------------------------------------------------
# Chi-Squared = 50.79 using 59 PHA bins.
# Reduced chi-squared = 0.9235 for 55 degrees of freedom
# Null hypothesis probability = 6.361120e-01
Photon flux (15-150 keV) in 5.228 sec: ( ) ph/cm2/s
Energy fluence (15-150 keV) : 0 ( 0 0 ) ergs/cm2
Single BB
Spectral model blackbody:
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : ( )
R^2/D10^2 : ( )
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25
25- 50
50-150
15-150
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : ( )
Norm : ( )
------------------------------------------------------------
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25
25- 50
50-150
15-150
Double BB
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : ( )
R1^2/D10^2 : ( )
kT2 [keV] : ( )
R2^2/D10^2 : ( )
------------------------------------------------------------
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25
25- 50
50-150
15-150
Peak spectrum fit
Power-law model
Time interval is from 0.104 sec. to 1.104 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.03241 ( -0.0577026 0.0574746 )
Norm@50keV : 9.43700E-02 ( -0.00344598 0.00344583 )
------------------------------------------------------------
# Chi-Squared = 76.80 using 59 PHA bins.
# Reduced chi-squared = 1.347 for 57 degrees of freedom
# Null hypothesis probability = 4.130603e-02
Photon flux (15-150 keV) in 1 sec: 10.8858 ( -0.400903 0.401 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.00897e-06 ( -4.11982e-08 4.13632e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.104 sec. to 1.104 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.448119 ( -0.246814 0.233155 )
Epeak [keV] : 147.794 ( -28.2241 59.8102 )
Norm@50keV : 0.177641 ( -0.0385885 0.0522405 )
------------------------------------------------------------
# Chi-Squared = 57.02 using 59 PHA bins.
# Reduced chi-squared = 1.018 for 56 degrees of freedom
# Null hypothesis probability = 4.368793e-01
Photon flux (15-150 keV) in 1 sec: 10.7962 ( ) ph/cm2/s
Energy fluence (15-150 keV) : 9.90931e-07 ( -4.3159e-08 4.2929e-08 ) ergs/cm2
Band function
Time interval is from 0.104 sec. to 1.104 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.448030 ( -0.221842 0.247466 )
beta : -10.00000 ( 8.02616e+09 8.02616e+09 )
Epeak [keV] : 147.762 ( -28.2132 59.813 )
Norm@50keV : 0.177656 ( -0.0386062 0.0522513 )
------------------------------------------------------------
# Chi-Squared = 57.02 using 59 PHA bins.
# Reduced chi-squared = 1.037 for 55 degrees of freedom
# Null hypothesis probability = 3.998096e-01
Photon flux (15-150 keV) in 1 sec: ( ) ph/cm2/s
Energy fluence (15-150 keV) : 0 ( 0 0 ) ergs/cm2
Single BB
Spectral model blackbody:
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : ( )
R^2/D10^2 : ( )
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25
25- 50
50-150
15-150
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : ( )
Norm : ( )
------------------------------------------------------------
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25
25- 50
50-150
15-150
Double BB
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : ( )
R1^2/D10^2 : ( )
kT2 [keV] : ( )
R2^2/D10^2 : ( )
------------------------------------------------------------
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25
25- 50
50-150
15-150
Plot creation:
Mon Aug 16 13:54:27 EDT 2010