batgrbproduct Analysis for Trigger=451901
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): Sat Apr 23 11:46:52 EDT 2011
Host Name: gcn5
Current Working Dir: /local/data/raid16/prebascript_archive/trigger451901/GCN5_download_cron
======================================================================
Trigger: 00451901 Segment: 000
BAT Trigger Time: 325179722.752 [s; MET]
Trigger Stop: 325179722.88 [s; MET]
UTC: 2011-04-22T15:41:55.870640 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 111.994986280231 Dec: 75.1057497440089 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 7.19
Image Trigger?: NO
Rate S/N Ratio: 27.9463772249642 [ if not an image trigger ]
Image S/N Ratio: 7.19
Flight Position: [ source = BAT ]
RA: 111.994986280231 Dec: 75.1057497440089 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 112.055205148116 Dec: 75.0999817682526 [deg; J2000]
{ 07h 28m 13.2s , +75d 05' 59.9" }
+/- 0.653963410765394 [arcmin] (estimated 90% radius based on SNR)
+/- 0.285912913309251 [arcmin] (formal 1-sigma fit error)
SNR: 55.7973342898424
Angular difference between Flight and Ground position is 0.991256 arcmin
Partial Coding Fraction: 0.2265625 [ including projection effects ]
Duration
T90: 25.9599999785423 +/- 0.566646277192499
Measured from: -5.55199986696243
to: 20.4080001115799 [s; relative to TRIGTIME]
T50: 11.0119999647141 +/- 0.200997490359531
Measured from: 2.60400015115738
to: 13.6160001158714 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 6.90400004386902
to: 7.90400004386902 [s; relative to TRIGTIME]
Total Fluence
Measured from: -11.1559999585152
to: 40.5720000267029 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 10.691460 19.880805 19.565605 5.594961
0.125072 0.153658 0.150199 0.101546 [error]
Peak 0.533978 1.190915 1.412811 0.538908
0.024912 0.033922 0.037868 0.027644 [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 4.66e-06 9.39e-06 1.47e-05 5.11e-05 4.10e-05 7.98e-05 erg/cm2
Error 1.39e-07 1.71e-07 1.99e-07 1.54e-06 5.38e-07 1.58e-06 erg/cm2
Peak flux Power-law 6.71e+00 9.20e+00 9.31e+00 1.71e+01 3.07e+01 4.23e+01 ph/cm2/s
Error 4.38e-01 3.67e-01 3.02e-01 1.19e+00 9.87e-01 1.40e+00 ph/cm2/s
Fluence Cutoff-PL 3.95e-06 9.45e-06 1.57e-05 3.27e-05 4.07e-05 6.18e-05 erg/cm2
Error 1.87e-07 1.80e-07 2.79e-07 2.82e-06 5.45e-07 2.81e-06 erg/cm2
Peak flux Cutoff-PL 6.19e+00 9.30e+00 9.67e+00 1.33e+01 3.04e+01 3.85e+01 ph/cm2/s
Error 5.69e-01 3.86e-01 4.05e-01 2.74e+00 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 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 1.350 0.023 - - 8.12e-02 1.15e-03 112.500 57
CPL 0.856 0.104 149.5 18.5 1.27e-01 1.16e-02 40.730 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 0.983 0.053 - - 2.67e-01 8.40e-03 61.960 57
CPL 0.704 0.217 281.6 356.6 3.51e-01 7.36e-02 56.860 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: 23.808000 sec.
T50 in the 50-300 keV band: 9.792000 sec.
=== Table of the duration information ==
Value tstart tstop
T100 51.728 -11.156 40.572
T90 25.960 -5.552 20.408
T50 11.012 2.604 13.616
Peak 1.000 6.904 7.904
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
112.0552 +75.1000 0.0035 44.7 -135.7 59.0864 55.8 TRIG_00451901
------------------------------------------
Foreground time interval of the image:
-11.156 40.572 (delta_t = 51.728 [sec])
Background time interval of the image:
-239.752 -11.156 (delta_t = 228.596 [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 -11.156 sec. to 40.572 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.35000 ( -0.0231335 0.0230456 )
Norm@50keV : 8.11955E-02 ( -0.0011501 0.00114817 )
------------------------------------------------------------
# Chi-Squared = 112.50 using 59 PHA bins.
# Reduced chi-squared = 1.9737 for 57 degrees of freedom
# Null hypothesis probability = 1.656984e-05
Photon flux (15-150 keV) in 51.73 sec: 9.78170 ( -0.161367 0.16182 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.10228e-05 ( -5.38489e-07 5.38473e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -11.156 sec. to 40.572 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.855569 ( -0.104774 0.102728 )
Epeak [keV] : 149.532 ( -14.9796 22.0015 )
Norm@50keV : 0.126895 ( -0.0109685 0.0121967 )
------------------------------------------------------------
# Chi-Squared = 40.73 using 59 PHA bins.
# Reduced chi-squared = 0.7273 for 56 degrees of freedom
# Null hypothesis probability = 9.376794e-01
Photon flux (15-150 keV) in 51.73 sec: 9.42208 ( ) ph/cm2/s
Energy fluence (15-150 keV) : 4.06858e-05 ( -5.44924e-07 5.44872e-07 ) ergs/cm2
Band function
Time interval is from -11.156 sec. to 40.572 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.814169 ( -0.125385 0.690001 )
beta : -1.77694 ( 1.77589 0.25671 )
Epeak [keV] : 139.759 ( -74.0165 26.4607 )
Norm@50keV : 0.132835 ( -0.0149002 0.18788 )
------------------------------------------------------------
# Chi-Squared = 39.83 using 59 PHA bins.
# Reduced chi-squared = 0.7242 for 55 degrees of freedom
# Null hypothesis probability = 9.383382e-01
Photon flux (15-150 keV) in 51.73 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 6.904 sec. to 7.904 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.982682 ( -0.0531768 0.0528217 )
Norm@50keV : 0.267033 ( -0.00840656 0.00839175 )
------------------------------------------------------------
# Chi-Squared = 61.96 using 59 PHA bins.
# Reduced chi-squared = 1.087 for 57 degrees of freedom
# Null hypothesis probability = 3.035675e-01
Photon flux (15-150 keV) in 1 sec: 30.7177 ( -0.985921 0.987245 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.90528e-06 ( -9.48913e-08 9.49371e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 6.904 sec. to 7.904 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.703920 ( -0.221917 0.211697 )
Epeak [keV] : 281.588 ( -97.4601 615.827 )
Norm@50keV : 0.351113 ( -0.0645533 0.0825932 )
------------------------------------------------------------
# Chi-Squared = 56.86 using 59 PHA bins.
# Reduced chi-squared = 1.015 for 56 degrees of freedom
# Null hypothesis probability = 4.428750e-01
Photon flux (15-150 keV) in 1 sec: 30.4325 ( ) ph/cm2/s
Energy fluence (15-150 keV) : 2.88941e-06 ( 0 0 ) ergs/cm2
Band function
Time interval is from 6.904 sec. to 7.904 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : 4.99980 ( -9779.09 -9779.09 )
beta : -1.01007 ( -0.0748758 0.0636973 )
Epeak [keV] : 27.0255 ( -26.6828 6.40089 )
Norm@50keV : 1.11089E+04 ( -8644.85 2.76812e+07 )
------------------------------------------------------------
# Chi-Squared = 59.82 using 59 PHA bins.
# Reduced chi-squared = 1.088 for 55 degrees of freedom
# Null hypothesis probability = 3.051869e-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:
Sat Apr 23 12:11:01 EDT 2011