batgrbproduct Analysis for Trigger=451757
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 May 7 15:17:13 EDT 2011
Host Name: gcn5
Current Working Dir: /local/data/raid16/prebascript_archive/trigger451757/SDC
======================================================================
Trigger: 00451757 Segment: 000
BAT Trigger Time: 324990150.912 [s; MET]
Trigger Stop: 324990151.936 [s; MET]
UTC: 2011-04-20T11:02:24.037860 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 2.16510709260475 Dec: -37.8550292612526 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 7.93
Image Trigger?: NO
Rate S/N Ratio: 12.6491106406735 [ if not an image trigger ]
Image S/N Ratio: 7.93
Flight Position: [ source = BAT ]
RA: 2.16510709260475 Dec: -37.8550292612526 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 2.16423302856111 Dec: -37.8769773099224 [deg; J2000]
{ 00h 08m 39.4s , -37d 52' 37.1" }
+/- 0.848945964384747 [arcmin] (estimated 90% radius based on SNR)
+/- 0.326646262569424 [arcmin] (formal 1-sigma fit error)
SNR: 38.4342411884367
Angular difference between Flight and Ground position is 1.317534 arcmin
Partial Coding Fraction: 0.1503906 [ including projection effects ]
Duration
T90: 13.8039999604225 +/- 1.33804779251485
Measured from: 1.43599998950958
to: 15.2399999499321 [s; relative to TRIGTIME]
T50: 4.69199997186661 +/- 0.398577501224954
Measured from: 5.96399998664856
to: 10.6559999585152 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 8.04399996995926
to: 9.04399996995926 [s; relative to TRIGTIME]
Total Fluence
Measured from: -0.103999972343445
to: 21.8159999847412 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 4.181681 3.948625 1.946505 0.289950
0.096592 0.094113 0.076731 0.056530 [error]
Peak 0.455986 0.502115 0.375951 0.075061
0.027156 0.028502 0.023832 0.015543 [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 1.78e-06 1.99e-06 1.58e-06 2.09e-06 6.12e-06 7.44e-06 erg/cm2
Error 1.03e-07 6.61e-08 8.21e-08 2.29e-07 2.01e-07 3.05e-07 erg/cm2
Peak flux Power-law 5.88e+00 4.69e+00 2.53e+00 1.98e+00 1.40e+01 1.51e+01 ph/cm2/s
Error 6.09e-01 3.00e-01 2.04e-01 3.21e-01 9.16e-01 9.24e-01 ph/cm2/s
Fluence Cutoff-PL 1.71e-06 2.02e-06 1.60e-06 1.58e-06 6.02e-06 6.90e-06 erg/cm2
Error 1.33e-07 7.57e-08 8.55e-08 5.52e-07 2.36e-07 6.31e-07 erg/cm2
Peak flux Cutoff-PL 5.69e+00 4.75e+00 2.57e+00 1.70e+00 1.39e+01 1.47e+01 ph/cm2/s
Error 7.53e-01 3.38e-01 2.35e-01 5.70e-01 9.64e-01 1.20e+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 2.326 0.068 - - 2.91e-02 1.08e-03 49.820 57
CPL 1.987 0.000 2.0 8.6 4.28e-02 3.09e-03 48.630 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 1.893 0.108 - - 9.78e-02 6.22e-03 41.080 57
CPL 1.737 0.517 88.5 0.0 1.17e-01 0.00e+00 40.650 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: 9.728000 sec.
T50 in the 50-300 keV band: 3.200000 sec.
=== Table of the duration information ==
Value tstart tstop
T100 21.920 -0.104 21.816
T90 13.804 1.436 15.240
T50 4.692 5.964 10.656
Peak 1.000 8.044 9.044
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
2.1642 -37.8770 0.0050 50.2 -34.1 8.6136 38.4 TRIG_00451757
------------------------------------------
Foreground time interval of the image:
-0.104 10.989 (delta_t = 11.093 [sec])
Background time interval of the image:
-239.912 -0.104 (delta_t = 239.808 [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 -0.104 sec. to 21.816 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.32611 ( -0.0676204 0.0688558 )
Norm@50keV : 2.90847E-02 ( -0.00107967 0.00107234 )
------------------------------------------------------------
# Chi-Squared = 49.82 using 59 PHA bins.
# Reduced chi-squared = 0.8740 for 57 degrees of freedom
# Null hypothesis probability = 7.389013e-01
Photon flux (15-150 keV) in 21.92 sec: 5.15770 ( -0.19876 0.200346 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.12267e-06 ( -2.00968e-07 2.01096e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.104 sec. to 21.816 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.98674 ( )
Epeak [keV] : 1.95101 ( -0.357292 16.8777 )
Norm@50keV : 4.27620E-02 ( -0.0029999 0.00318107 )
------------------------------------------------------------
# Chi-Squared = 48.63 using 59 PHA bins.
# Reduced chi-squared = 0.8684 for 56 degrees of freedom
# Null hypothesis probability = 7.472575e-01
Photon flux (15-150 keV) in 21.92 sec: 5.05579 ( -0.23205 0.23455 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.02493e-06 ( -2.36363e-07 2.35618e-07 ) ergs/cm2
Band function
Time interval is from -0.104 sec. to 21.816 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.98338 ( 1.94836 0.0284401 )
beta : -10.00000 ( 9.74209e+10 9.74209e+10 )
Epeak [keV] : 2.41962 ( -0.485629 16.5167 )
Norm@50keV : 4.29180E-02 ( -0.00139699 0.00139704 )
------------------------------------------------------------
# Chi-Squared = 48.66 using 59 PHA bins.
# Reduced chi-squared = 0.8848 for 55 degrees of freedom
# Null hypothesis probability = 7.139765e-01
Photon flux (15-150 keV) in 21.92 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 8.044 sec. to 9.044 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.89328 ( -0.106792 0.109268 )
Norm@50keV : 9.77924E-02 ( -0.00623497 0.00619592 )
------------------------------------------------------------
# Chi-Squared = 41.08 using 59 PHA bins.
# Reduced chi-squared = 0.7208 for 57 degrees of freedom
# Null hypothesis probability = 9.444749e-01
Photon flux (15-150 keV) in 1 sec: 13.9943 ( -0.913863 0.918579 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.9903e-07 ( -5.68999e-08 5.70398e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 8.044 sec. to 9.044 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.73658 ( -0.430875 0.602415 )
Epeak [keV] : 88.5404 ( )
Norm@50keV : 0.116647 ( )
------------------------------------------------------------
# Chi-Squared = 40.65 using 59 PHA bins.
# Reduced chi-squared = 0.7259 for 56 degrees of freedom
# Null hypothesis probability = 9.387883e-01
Photon flux (15-150 keV) in 1 sec: 13.8692 ( -0.9631 0.9643 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.93854e-07 ( -5.8919e-08 5.8778e-08 ) ergs/cm2
Band function
Time interval is from 8.044 sec. to 9.044 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.73658 ( 1.74625 0.21694 )
beta : -10.00000 ( 2.2487e+13 2.2487e+13 )
Epeak [keV] : 88.5268 ( -28.3286 -88.5268 )
Norm@50keV : 0.116620 ( -0.0245158 0.0704029 )
------------------------------------------------------------
# Chi-Squared = 40.65 using 59 PHA bins.
# Reduced chi-squared = 0.7391 for 55 degrees of freedom
# Null hypothesis probability = 9.256730e-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 May 7 16:26:36 EDT 2011