batgrbproduct Analysis for Trigger=520928
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): Fri Apr 27 11:04:00 EDT 2012
Host Name: gcn5
Current Working Dir: /local/data/raid16/prebascript_archive/trigger520928/GCN5_download_cron
======================================================================
Trigger: 00520928 Segment: 000
BAT Trigger Time: 357133104 [s; MET]
Trigger Stop: 357133168 [s; MET]
UTC: 2012-04-26T11:38:15.857520 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 75.7196373481322 Dec: -26.3145506802809 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 7.05
Image Trigger?: YES
Rate S/N Ratio: 0 [ if not an image trigger ]
Image S/N Ratio: 7.05
Flight Position: [ source = BAT ]
RA: 75.7196373481322 Dec: -26.3145506802809 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 75.723367565164 Dec: -26.3572570180807 [deg; J2000]
{ 05h 02m 53.6s , -26d 21' 26.1" }
+/- 3.3324740741614 [arcmin] (estimated 90% radius based on SNR)
+/- 2.13827156987774 [arcmin] (formal 1-sigma fit error)
SNR: 5.44889821181927
Angular difference between Flight and Ground position is 2.570219 arcmin
Partial Coding Fraction: 0.609375 [ including projection effects ]
Duration
T90: 64 +/-
Measured from: 0
to: 64 [s; relative to TRIGTIME]
T50: 64 +/-
Measured from: 0
to: 64 [s; relative to TRIGTIME]
WARNING: battblocks failed. Used TDRSS fore/background intervals
Fluence
Peak Flux (peak 64 second)
Measured from: 0
to: 64 [s; relative to TRIGTIME]
Total Fluence
Measured from: 0
to: 64 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.200654 0.212361 -0.029967 -0.023524
0.053280 0.054499 0.048030 0.041517 [error]
Peak 0.200654 0.212361 -0.029967 -0.023524
0.053280 0.054499 0.048030 0.041517 [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 6.96e-08 6.35e-08 3.97e-08 3.76e-08 1.88e-07 2.14e-07 erg/cm2
Error 2.56e-08 2.62e-08 2.92e-08 5.64e-08 8.00e-08 1.09e-07 erg/cm2
Peak flux Power-law 3.67e-02 1.89e-02 5.92e-03 2.34e-03 6.28e-02 6.43e-02 ph/cm2/s
Error 1.38e-02 7.53e-03 4.20e-03 3.27e-03 2.17e-02 2.24e-02 ph/cm2/s
Fluence Cutoff-PL 6.72e-08 9.91e-08 8.89e-09 5.52e-12 1.75e-07 0.00e+00 erg/cm2
Error 2.97e-08 4.34e-08 2.03e-08 1.27e-09 6.09e-08 0.00e+00 erg/cm2
Peak flux Cutoff-PL 3.38e-02 3.01e-02 1.56e-03 5.20e-07 6.55e-02 6.55e-02 ph/cm2/s
Error 1.56e-02 1.20e-02 3.27e-03 1.10e-04 2.04e-02 2.04e-02 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 3.34e-02 3.03e-02 6.53e-02 0.00e+00 0.00e+00 0.00e+00 ph/cm2/s
Error 1.51e-02 2.01e-02 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 2.682 0.670 - - 2.85e-04 1.63e-04 57.670 57
CPL -4.367 0.354 27.8 7.2 1.86e+01 0.00e+00 50.280 56
The chi2 of BB fit is 50.71 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 2.682 0.670 - - 2.85e-04 1.63e-04 57.670 57
CPL -4.367 0.354 27.8 7.2 1.86e+01 0.00e+00 50.280 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 64.000 0.000 64.000
T90 64.000 0.000 64.000
T50 64.000 0.000 64.000
Peak 64.000 0.000 64.000
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
75.7234 -26.3573 0.0351 39.0 -14.4 0.5560 5.4 TRIG_00520928
------------------------------------------
Foreground time interval of the image:
0.000 22.470 (delta_t = 22.470 [sec])
24.000 64.000 (delta_t = 40.000 [sec])
Background time interval of the image:
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
Multiple GTIs in the spectrum
tstart tstop
0.000000 22.470000
24.000000 64.000000
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.68234 ( -0.578103 0.761742 )
Norm@50keV : 2.84846E-04 ( -0.000154642 0.000171563 )
------------------------------------------------------------
# Chi-Squared = 57.67 using 59 PHA bins.
# Reduced chi-squared = 1.012 for 57 degrees of freedom
# Null hypothesis probability = 4.503662e-01
Photon flux (15-150 keV) in 62.47 sec: 6.28498E-02 ( -0.0216537 0.0217811 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.88258e-07 ( -7.50277e-08 8.49361e-08 ) ergs/cm2
Cutoff power-law model
Multiple GTIs in the spectrum
tstart tstop
0.000000 22.470000
24.000000 64.000000
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -4.36660 ( 2.96915 3.67663 )
Epeak [keV] : 27.8125 ( -7.6139 6.72715 )
Norm@50keV : 18.6051 ( )
------------------------------------------------------------
# Chi-Squared = 50.28 using 59 PHA bins.
# Reduced chi-squared = 0.8978 for 56 degrees of freedom
# Null hypothesis probability = 6.903896e-01
Photon flux (15-150 keV) in 62.47 sec: 6.54778E-02 ( -0.020317 0.0204999 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.75195e-07 ( -5.94739e-08 6.23313e-08 ) ergs/cm2
Band function
Multiple GTIs in the spectrum
tstart tstop
0.000000 22.470000
24.000000 64.000000
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : 4.09721 ( -8.11564 -7.40699 )
beta : -9.99810 ( 1676.85 1686.85 )
Epeak [keV] : 28.4609 ( -5.32719 6.29296 )
Norm@50keV : 10.4695 ( -10.4727 66.2318 )
------------------------------------------------------------
# Chi-Squared = 50.30 using 59 PHA bins.
# Reduced chi-squared = 0.9146 for 55 degrees of freedom
# Null hypothesis probability = 6.543936e-01
Photon flux (15-150 keV) in 62.47 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] : 6.96793 (-1.62215 1.96015)
R^2/D10^2 : 0.145002 (-0.145002 0.289494)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
# Chi-Squared = 50.71 using 59 PHA bins.
# Reduced chi-squared = 0.8897 for 57 degrees of freedom
# Null hypothesis probability = 7.085026e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 7.032e-08 4.292e-08
25- 50 9.544e-08 5.882e-08
50-150 1.556e-08 1.287e-08
15-150 1.813e-07 1.111e-07
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 23.8872 (-11.088 20.4819)
Norm : 0.668804 (-0.316548 0.580774)
------------------------------------------------------------
# Chi-Squared = 54.16 using 59 PHA bins.
# Reduced chi-squared = 0.9501 for 57 degrees of freedom
# Null hypothesis probability = 5.824673e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 7.423e-08 4.385e-08
25- 50 7.385e-08 4.701e-08
50-150 2.935e-08 2.977e-08
15-150 1.774e-07 1.196e-07
Double BB
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 6.95380 (-6.95914 -6.95914)
R1^2/D10^2 : 0.103882 (-0.103798 -0.103798)
kT2 [keV] : 6.99024 (-6.97231 -6.97231)
R2^2/D10^2 : 4.14337E-02 (-0.0413157 -0.0413157)
------------------------------------------------------------
# Chi-Squared = 50.71 using 59 PHA bins.
# Reduced chi-squared = 0.9220 for 55 degrees of freedom
# Null hypothesis probability = 6.390577e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 7.035e-08 1.963e+00
25- 50 9.539e-08 1.361e+01
50-150 1.552e-08 4.036e+02
15-150 1.813e-07 3.633e+02
Peak spectrum fit
Power-law model
Time interval is from 24.000 sec. to 64.000 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.68234 ( -0.578103 0.761742 )
Norm@50keV : 2.84846E-04 ( -0.000154642 0.000171563 )
------------------------------------------------------------
# Chi-Squared = 57.67 using 59 PHA bins.
# Reduced chi-squared = 1.012 for 57 degrees of freedom
# Null hypothesis probability = 4.503662e-01
Photon flux (15-150 keV) in 62.47 sec: 6.28498E-02 ( -0.0216537 0.0217811 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.88258e-07 ( -7.50277e-08 8.49361e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 24.000 sec. to 64.000 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -4.36660 ( 2.96915 3.67663 )
Epeak [keV] : 27.8125 ( -7.6139 6.72715 )
Norm@50keV : 18.6051 ( )
------------------------------------------------------------
# Chi-Squared = 50.28 using 59 PHA bins.
# Reduced chi-squared = 0.8978 for 56 degrees of freedom
# Null hypothesis probability = 6.903896e-01
Photon flux (15-150 keV) in 62.47 sec: 6.54778E-02 ( -0.020317 0.0204999 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.75195e-07 ( -5.94739e-08 6.23313e-08 ) ergs/cm2
Band function
Time interval is from 24.000 sec. to 64.000 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : 4.09721 ( -17.3273 -7.40699 )
beta : -9.99810 ( 1676.85 1686.85 )
Epeak [keV] : 28.4609 ( -5.32719 6.29296 )
Norm@50keV : 10.4695 ( -10.4727 66.2318 )
------------------------------------------------------------
# Chi-Squared = 50.30 using 59 PHA bins.
# Reduced chi-squared = 0.9146 for 55 degrees of freedom
# Null hypothesis probability = 6.543936e-01
Photon flux (15-150 keV) in 62.47 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] : 6.96793 (-1.62215 1.96015)
R^2/D10^2 : 0.145002 (-0.145002 0.289494)
(R is the radius in km and D10 is the distance to the source in units of 10 kpc)
------------------------------------------------------------
# Chi-Squared = 50.71 using 59 PHA bins.
# Reduced chi-squared = 0.8897 for 57 degrees of freedom
# Null hypothesis probability = 7.085026e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 7.032e-08 4.129e-08
25- 50 9.544e-08 6.028e-08
50-150 1.556e-08 1.269e-08
15-150 1.813e-07 1.106e-07
Thermal bremsstrahlung (OTTB)
Spectral model: thermal bremsstrahlung
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT [keV] : 23.8872 (-11.088 20.4819)
Norm : 0.668804 (-0.316548 0.580774)
------------------------------------------------------------
# Chi-Squared = 54.16 using 59 PHA bins.
# Reduced chi-squared = 0.9501 for 57 degrees of freedom
# Null hypothesis probability = 5.824673e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 7.423e-08 4.467e-08
25- 50 7.385e-08 4.795e-08
50-150 2.935e-08 2.847e-08
15-150 1.774e-07 1.178e-07
Double BB
Spectral model: bbodyrad<1> + bbodyrad<2>
------------------------------------------------------------
Parameters : value Lower 90% Upper 90%
kT1 [keV] : 6.95380 (-6.95914 -6.95914)
R1^2/D10^2 : 0.103882 (-0.103798 -0.103798)
kT2 [keV] : 6.99024 (-6.97231 -6.97231)
R2^2/D10^2 : 4.14337E-02 (-0.0413157 -0.0413157)
------------------------------------------------------------
# Chi-Squared = 50.71 using 59 PHA bins.
# Reduced chi-squared = 0.9220 for 55 degrees of freedom
# Null hypothesis probability = 6.390577e-01
Energy Fluence 90% Error
[keV] [erg/cm2] [erg/cm2]
15- 25 7.035e-08 1.637e+00
25- 50 9.539e-08 1.507e+01
50-150 1.552e-08 4.104e+02
15-150 1.813e-07 3.936e+02
Plot creation:
Fri Apr 27 11:41:14 EDT 2012