batgrbproduct Analysis for Trigger=518731
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): Tue Mar 27 11:27:48 EDT 2012
Host Name: gcn5
Current Working Dir: /local/data/raid16/prebascript_archive/trigger518731/GCN5_download_cron
======================================================================
Trigger: 00518731 Segment: 000
BAT Trigger Time: 354509724.672 [s; MET]
Trigger Stop: 354509726.72 [s; MET]
UTC: 2012-03-27T02:55:16.636400 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 246.828429216695 Dec: -29.4152103588065 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 8.58
Image Trigger?: NO
Rate S/N Ratio: 8.54400374531753 [ if not an image trigger ]
Image S/N Ratio: 8.58
Flight Position: [ source = BAT ]
RA: 246.828429216695 Dec: -29.4152103588065 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 246.854108872735 Dec: -29.4153675211979 [deg; J2000]
{ 16h 27m 25.0s , -29d 24' 55.3" }
+/- 1.13818626542528 [arcmin] (estimated 90% radius based on SNR)
+/- 0.311850856120789 [arcmin] (formal 1-sigma fit error)
SNR: 25.282126944567
Angular difference between Flight and Ground position is 1.342180 arcmin
Partial Coding Fraction: 0.765625 [ including projection effects ]
Duration
T90: 62.8839999437332 +/- 7.52171254966162
Measured from: -6.99199986457825
to: 55.892000079155 [s; relative to TRIGTIME]
T50: 23.2359999418259 +/- 3.6503720058772
Measured from: 16.5640001296997
to: 39.8000000715256 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 37.0879999995232
to: 38.0879999995232 [s; relative to TRIGTIME]
Total Fluence
Measured from: -15.7879999876022
to: 74.5760000348091 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 1.625868 2.193829 1.657619 0.390345
0.065209 0.058686 0.049827 0.040466 [error]
Peak 0.112399 0.168922 0.172861 0.042562
0.008118 0.008449 0.007896 0.005449 [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 4.96e-07 9.01e-07 1.26e-06 3.66e-06 3.61e-06 6.32e-06 erg/cm2
Error 3.14e-08 3.27e-08 5.09e-08 3.40e-07 1.23e-07 3.68e-07 erg/cm2
Peak flux Power-law 1.03e+00 1.24e+00 1.07e+00 1.58e+00 3.90e+00 4.92e+00 ph/cm2/s
Error 1.06e-01 7.61e-02 6.24e-02 2.01e-01 2.07e-01 2.62e-01 ph/cm2/s
Fluence Cutoff-PL 4.78e-07 9.11e-07 1.27e-06 2.89e-06 5.55e-06 0.00e+00 erg/cm2
Error 3.90e-08 3.57e-08 5.53e-08 8.79e-07 8.86e-07 0.00e+00 erg/cm2
Peak flux Cutoff-PL 1.02e+00 1.24e+00 1.08e+00 1.48e+00 3.89e+00 4.81e+00 ph/cm2/s
Error 1.28e-01 7.96e-02 7.26e-02 3.69e-01 2.15e-01 4.29e-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 1.520 0.061 - - 4.22e-03 1.35e-04 53.050 57
CPL 1.352 0.219 206.0 0.0 5.06e-03 0.00e+00 51.470 56
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.208 0.092 - - 3.32e-02 1.68e-03 53.120 57
CPL 1.101 0.238 444.2 0.0 3.70e-02 0.00e+00 53.050 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: 49.152000 sec.
T50 in the 50-300 keV band: 27.200000 sec.
=== Table of the duration information ==
Value tstart tstop
T100 90.364 -15.788 74.576
T90 62.884 -6.992 55.892
T50 23.236 16.564 39.800
Peak 1.000 37.088 38.088
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
246.8541 -29.4154 0.0076 17.1 76.2 2.0621 25.3 TRIG_00518731
------------------------------------------
Foreground time interval of the image:
-15.788 23.929 (delta_t = 39.717 [sec])
Background time interval of the image:
-239.672 -15.788 (delta_t = 223.884 [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 -15.788 sec. to 74.576 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.51960 ( -0.0611986 0.0612063 )
Norm@50keV : 4.22245E-03 ( -0.000135069 0.00013502 )
------------------------------------------------------------
# Chi-Squared = 53.05 using 59 PHA bins.
# Reduced chi-squared = 0.9307 for 57 degrees of freedom
# Null hypothesis probability = 6.239041e-01
Photon flux (15-150 keV) in 90.36 sec: 0.529953 ( -0.018489 0.0185493 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.60818e-06 ( -1.22888e-07 1.23168e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -15.788 sec. to 74.576 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.35156 ( -0.239527 0.19772 )
Epeak [keV] : 205.969 ( )
Norm@50keV : 5.06434E-03 ( )
------------------------------------------------------------
# Chi-Squared = 51.47 using 59 PHA bins.
# Reduced chi-squared = 0.9191 for 56 degrees of freedom
# Null hypothesis probability = 6.467880e-01
Photon flux (15-150 keV) in 90.36 sec: 0.523377 ( -0.020343 0.020404 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.54699e-06 ( -7.83493e-07 9.88421e-07 ) ergs/cm2
Band function
Time interval is from -15.788 sec. to 74.576 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : 1.60938 ( -2.30075 -2.17966 )
beta : -1.56782 ( -0.0780266 0.0738666 )
Epeak [keV] : 29.7426 ( -6.24113 74.5416 )
Norm@50keV : 0.800333 ( -0.798907 156.531 )
------------------------------------------------------------
# Chi-Squared = 48.63 using 59 PHA bins.
# Reduced chi-squared = 0.8842 for 55 degrees of freedom
# Null hypothesis probability = 7.151185e-01
Photon flux (15-150 keV) in 90.36 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] : 16.2592 ( )
R^2/D10^2 : 4.31360E-02 ( )
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
# Chi-Squared = 263.40 using 59 PHA bins.
# Reduced chi-squared = 4.6210 for 57 degrees of freedom
# Null hypothesis probability = 2.721548e-28
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 2.123e-07 1.473e-08
25- 50 9.055e-07 4.075e-08
50-150 1.683e-06 1.030e-07
15-150 2.801e-06 1.071e-07
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 199.990 ( )
Norm : 2.16035 (-2.16035 -2.16035)
------------------------------------------------------------
# Chi-Squared = 54.92 using 59 PHA bins.
# Reduced chi-squared = 0.9635 for 57 degrees of freedom
# Null hypothesis probability = 5.534332e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 4.862e-07 2.465e-07
25- 50 9.353e-07 4.776e-07
50-150 2.051e-06 1.045e-06
15-150 3.473e-06 1.767e-06
Double BB
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 7.14338 (-0.766731 0.841514)
R1^2/D10^2 : 0.511064 (-0.163165 0.258688)
kT2 [keV] : 27.6793 (-2.8345 3.80255)
R2^2/D10^2 : 5.52973E-03 (-0.00200447 0.00264266)
------------------------------------------------------------
# Chi-Squared = 48.98 using 59 PHA bins.
# Reduced chi-squared = 0.8906 for 55 degrees of freedom
# Null hypothesis probability = 7.025342e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 4.493e-07 5.227e-08
25- 50 9.247e-07 6.276e-08
50-150 2.180e-06 2.001e-07
15-150 3.554e-06 2.783e-07
Peak spectrum fit
Power-law model
Time interval is from 37.088 sec. to 38.088 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.20840 ( -0.0920075 0.0916756 )
Norm@50keV : 3.31750E-02 ( -0.00168331 0.00168298 )
------------------------------------------------------------
# Chi-Squared = 53.12 using 59 PHA bins.
# Reduced chi-squared = 0.9319 for 57 degrees of freedom
# Null hypothesis probability = 6.214145e-01
Photon flux (15-150 keV) in 1 sec: 3.89872 ( -0.206433 0.206942 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.35781e-07 ( -1.87088e-08 1.87887e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 37.088 sec. to 38.088 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.10142 ( -0.361914 0.113294 )
Epeak [keV] : 444.243 ( )
Norm@50keV : 3.70457E-02 ( )
------------------------------------------------------------
# Chi-Squared = 53.05 using 59 PHA bins.
# Reduced chi-squared = 0.9473 for 56 degrees of freedom
# Null hypothesis probability = 5.873389e-01
Photon flux (15-150 keV) in 1 sec: 3.88569 ( -0.2154 0.21424 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.76554e-07 ( -1.6184e-07 1.10924e-07 ) ergs/cm2
Band function
Time interval is from 37.088 sec. to 38.088 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.14286 ( 0.838955 5.83181 )
beta : -1.54004 ( 6.82236 16.2362 )
Epeak [keV] : 744.606 ( -436.273 -744.916 )
Norm@50keV : 3.55090E-02 ( -0.00355793 0.0101117 )
------------------------------------------------------------
# Chi-Squared = 53.00 using 59 PHA bins.
# Reduced chi-squared = 0.9637 for 55 degrees of freedom
# Null hypothesis probability = 5.512787e-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] : 20.0956 ( )
R^2/D10^2 : 0.174615 ( )
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
# Chi-Squared = 137.60 using 59 PHA bins.
# Reduced chi-squared = 2.4140 for 57 degrees of freedom
# Null hypothesis probability = 1.290279e-08
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 1.357e-08 1.460e-09
25- 50 6.780e-08 5.530e-09
50-150 2.031e-07 1.700e-08
15-150 2.845e-07 1.810e-08
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 199.994 ( )
Norm : 16.2428 (-16.2428 -16.2428)
------------------------------------------------------------
# Chi-Squared = 95.08 using 59 PHA bins.
# Reduced chi-squared = 1.668 for 57 degrees of freedom
# Null hypothesis probability = 1.161197e-03
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 4.045e-08 2.084e-08
25- 50 7.781e-08 4.022e-08
50-150 1.706e-07 8.805e-08
15-150 2.889e-07 1.501e-07
Double BB
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 6.85334 (-1.26248 1.58495)
R1^2/D10^2 : 3.52484 (-1.7657 3.91195)
kT2 [keV] : 30.3265 (-3.95589 6.13811)
R2^2/D10^2 : 4.01296E-02 (-0.0181908 0.0165377)
------------------------------------------------------------
# Chi-Squared = 53.66 using 59 PHA bins.
# Reduced chi-squared = 0.9757 for 55 degrees of freedom
# Null hypothesis probability = 5.257838e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 3.174e-08 8.070e-09
25- 50 6.971e-08 1.077e-08
50-150 2.351e-07 3.355e-08
15-150 3.366e-07 4.370e-08
Plot creation:
Tue Mar 27 11:46:38 EDT 2012