batgrbproduct Analysis for Trigger=458907
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 8 02:13:09 EDT 2011
Host Name: gcn5
Current Working Dir: /local/data/raid16/prebascript_archive/trigger458907/GCN5_download_cron
======================================================================
Trigger: 00458907 Segment: 000
BAT Trigger Time: 334439873.612 [s; MET]
Trigger Stop: 334439873.644 [s; MET]
UTC: 2011-08-07T19:57:46.375020 [includes UTCF correction]
Where From?: (*SHORT BURST*) TDRSS scaled map message
BAT
RA: 278.696248288915 Dec: -8.76002493492473 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 7.65
Image Trigger?: NO
Rate S/N Ratio: 18.9472953214964 [ if not an image trigger ]
Image S/N Ratio: 7.65
Flight Position: [ source = BAT ]
RA: 278.696248288915 Dec: -8.76002493492473 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 278.708703651202 Dec: -8.7578781038455 [deg; J2000]
{ 18h 34m 50.1s , -08d 45' 28.4" }
+/- 2.41320834554887 [arcmin] (estimated 90% radius based on SNR)
+/- 1.28527463692386 [arcmin] (formal 1-sigma fit error)
SNR: 8.64080796653148
Angular difference between Flight and Ground position is 0.749754 arcmin
Partial Coding Fraction: 0.8984375 [ including projection effects ]
Duration
T90: 0.031999945640564 +/- 0.0113137314268704
Measured from: 0.00400012731552124
to: 0.0360000729560852 [s; relative to TRIGTIME]
T50: 0.015999972820282 +/- 0.00894423672410898
Measured from: 0.00800013542175293
to: 0.0240001082420349 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: -0.477999985218048
to: 0.522000014781952 [s; relative to TRIGTIME]
Total Fluence
Measured from: 0
to: 0.0400000214576721 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.007058 0.015344 0.006628 0.001233
0.002286 0.002333 0.001753 0.001015 [error]
Peak 0.008666 0.012645 0.004313 -0.003023
0.007805 0.006970 0.006042 0.005531 [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 3.00e-09 3.76e-09 3.44e-09 5.49e-09 1.21e-08 1.57e-08 erg/cm2
Error 8.81e-10 8.27e-10 9.63e-10 2.78e-09 2.69e-09 4.19e-09 erg/cm2
Peak flux Power-law 1.24e-01 8.87e-02 4.18e-02 2.76e-02 2.68e-01 2.83e-01 ph/cm2/s
Error 1.04e-01 7.27e-02 4.52e-02 6.97e-02 1.69e-01 1.81e-01 ph/cm2/s
Fluence Cutoff-PL 2.55e-09 5.77e-09 3.64e-09 3.60e-10 1.23e-08 1.23e-08 erg/cm2
Error 9.77e-10 1.57e-09 1.64e-09 9.00e-10 2.70e-09 2.74e-09 erg/cm2
Peak flux Cutoff-PL 1.04e-01 1.13e-01 2.90e-02 9.74e-04 2.47e-01 2.47e-01 ph/cm2/s
Error 1.15e-01 8.84e-02 4.58e-02 6.39e-02 1.74e-01 1.87e-01 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 0.00e+00 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 2.129 0.296 - - 3.24e-02 7.52e-03 59.730 57
CPL -0.698 2.566 40.5 8.0 1.45e+00 8.28e+01 51.910 56
The chi2 of BB fit is 52.47 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 2.087 1.575 - - 1.72e-03 1.43e-03 50.220 57
CPL 0.214 0.000 35.2 0.0 2.45e-02 0.00e+00 49.950 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: 0.000000 sec.
T50 in the 50-300 keV band: 0.000000 sec.
=== Table of the duration information ==
Value tstart tstop
T100 0.040 0.000 0.040
T90 0.032 0.004 0.036
T50 0.016 0.008 0.024
Peak 1.000 -0.478 0.522
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
278.7087 -8.7579 0.0222 19.8 23.7 0.0325 8.6 TRIG_00458907
------------------------------------------
Foreground time interval of the image:
0.000 0.040 (delta_t = 0.040 [sec])
Background time interval of the image:
-239.612 0.000 (delta_t = 239.612 [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 0.000 sec. to 0.040 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.12947 ( -0.289862 0.302672 )
Norm@50keV : 3.23978E-02 ( -0.00757153 0.00746747 )
------------------------------------------------------------
# Chi-Squared = 59.73 using 59 PHA bins.
# Reduced chi-squared = 1.048 for 57 degrees of freedom
# Null hypothesis probability = 3.768964e-01
Photon flux (15-150 keV) in 0.04 sec: 5.17262 ( -1.182 1.18445 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.20768e-08 ( -2.69222e-09 2.69614e-09 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.000 sec. to 0.040 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.697669 ( -3.31058 1.82165 )
Epeak [keV] : 40.5075 ( -7.49678 8.55089 )
Norm@50keV : 1.45055 ( -1.50835 164.014 )
------------------------------------------------------------
# Chi-Squared = 51.91 using 59 PHA bins.
# Reduced chi-squared = 0.9269 for 56 degrees of freedom
# Null hypothesis probability = 6.304890e-01
Photon flux (15-150 keV) in 0.04 sec: 5.50021 ( -1.20298 1.2083 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.2289e-08 ( -2.70004e-09 2.69664e-09 ) ergs/cm2
Band function
Time interval is from 0.000 sec. to 0.040 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : 0.696186 ( 1.18327 1.34251 )
beta : -10.00000 ( 1.33911e+11 1.33911e+11 )
Epeak [keV] : 40.5022 ( -7.66044 8.64643 )
Norm@50keV : 1.44724 ( -1.51911 175.97 )
------------------------------------------------------------
# Chi-Squared = 51.91 using 59 PHA bins.
# Reduced chi-squared = 0.9438 for 55 degrees of freedom
# Null hypothesis probability = 5.935813e-01
Photon flux (15-150 keV) in 0.04 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] : 10.2877 (-1.68785 1.94804)
R^2/D10^2 : 2.70747 (-1.41436 2.79123)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
# Chi-Squared = 52.47 using 59 PHA bins.
# Reduced chi-squared = 0.9206 for 57 degrees of freedom
# Null hypothesis probability = 6.453324e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 2.356e-09 8.836e-10
25- 50 6.093e-09 1.766e-09
50-150 3.450e-09 1.486e-09
15-150 1.190e-08 3.700e-09
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 55.3798 (-17.5238 31.2047)
Norm : 30.8205 (-9.24456 11.0579)
------------------------------------------------------------
# Chi-Squared = 55.36 using 59 PHA bins.
# Reduced chi-squared = 0.9712 for 57 degrees of freedom
# Null hypothesis probability = 5.369658e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 3.055e-09 8.222e-10
25- 50 4.532e-09 1.156e-09
50-150 4.816e-09 1.941e-09
15-150 1.240e-08 3.332e-09
Double BB
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 9.35692 (-3.08742 1.88701)
R1^2/D10^2 : 3.73685 (-1.93771 4.70792)
kT2 [keV] : 194.067 (-175.021 -175.022)
R2^2/D10^2 : 2.02420E-04 (-0.000170844 1.37669)
------------------------------------------------------------
# Chi-Squared = 49.30 using 59 PHA bins.
# Reduced chi-squared = 0.8964 for 55 degrees of freedom
# Null hypothesis probability = 6.912126e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 2.606e-09 1.035e-09
25- 50 5.943e-09 2.625e-09
50-150 4.583e-09 1.712e-09
15-150 1.313e-08 4.610e-09
Peak spectrum fit
Power-law model
Time interval is from -0.478 sec. to 0.522 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.08749 ( -1.23895 1.91049 )
Norm@50keV : 1.71526E-03 ( -0.00144915 0.00140103 )
------------------------------------------------------------
# Chi-Squared = 50.22 using 59 PHA bins.
# Reduced chi-squared = 0.8811 for 57 degrees of freedom
# Null hypothesis probability = 7.252557e-01
Photon flux (15-150 keV) in 1 sec: 0.268200 ( -0.169235 0.169265 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.59181e-08 ( -1.11577e-08 1.32173e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.478 sec. to 0.522 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.213623 ( )
Epeak [keV] : 35.2431 ( )
Norm@50keV : 2.45141E-02 ( )
------------------------------------------------------------
# Chi-Squared = 49.95 using 59 PHA bins.
# Reduced chi-squared = 0.8919 for 56 degrees of freedom
# Null hypothesis probability = 7.020523e-01
Photon flux (15-150 keV) in 1 sec: 0.246944 ( -0.168231 0.180608 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.26566e-08 ( -8.69199e-09 1.52218e-08 ) ergs/cm2
Band function
Time interval is from -0.478 sec. to 0.522 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : 4.77507 ( -10.4516 -10.4516 )
beta : -3.58794 ( 3.58181 3.18129 )
Epeak [keV] : 32.8092 ( -32.81 22.8673 )
Norm@50keV : 41.7677 ( -42.0868 31.3369 )
------------------------------------------------------------
# Chi-Squared = 49.89 using 59 PHA bins.
# Reduced chi-squared = 0.9071 for 55 degrees of freedom
# Null hypothesis probability = 6.696494e-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] : 8.92568 (-4.43972 9.85575)
R^2/D10^2 : 0.200913 (-0.200934 2.8779)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
# Chi-Squared = 49.94 using 59 PHA bins.
# Reduced chi-squared = 0.8761 for 57 degrees of freedom
# Null hypothesis probability = 7.348858e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 3.103e-09 2.169e-09
25- 50 6.510e-09 5.000e-09
50-150 2.421e-09 2.243e-09
15-150 1.203e-08 8.680e-09
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 50.6600 (-50.66 -50.66)
Norm : 1.52591 (-1.52591 5.07609)
------------------------------------------------------------
# Chi-Squared = 50.06 using 59 PHA bins.
# Reduced chi-squared = 0.8782 for 57 degrees of freedom
# Null hypothesis probability = 7.308497e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 3.742e-09 2.670e-09
25- 50 5.400e-09 3.817e-09
50-150 5.307e-09 5.460e-09
15-150 1.445e-08 1.137e-08
Double BB
R1^2/D10^2 : 2.43241E+05 ( )
kT2 [keV] : 9.65394 (-4.65967 12.4285)
R2^2/D10^2 : 0.140913 ( )
------------------------------------------------------------
# Chi-Squared = 49.86 using 59 PHA bins.
# Chi-Squared = 49.49 using 59 PHA bins.
# Chi-Squared = 49.46 using 59 PHA bins.
# Reduced chi-squared = 0.9066 for 55 degrees of freedom
# Reduced chi-squared = 0.8998 for 55 degrees of freedom
# Reduced chi-squared = 0.8992 for 55 degrees of freedom
# Null hypothesis probability = 6.706686e-01
# Null hypothesis probability = 6.842675e-01
# Null hypothesis probability = 6.854995e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 3.135e-09 2.119e-09
25- 50 6.332e-09 4.106e-09
50-150 2.619e-09 2.342e-09
15-150 1.209e-08 8.875e-09
Plot creation:
Mon Aug 8 02:56:18 EDT 2011