batgrbproduct Analysis for Trigger=325461
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 page will be updated for up to 8 downlinks after the trigger.
======================================================================
BAT GRB EVENT DATA PROCESSING REPORT
Process Script Ver: batgrbproduct v2.41
Process Start Time (local time): Sun Sep 21 22:58:42 EDT 2008
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger325461/GCN5_download_cron
======================================================================
Trigger: 00325461 Segment: 000
BAT Trigger Time: 243676512 [s; MET]
Trigger Stop: 243676576 [s; MET]
UTC: 2008-09-21T07:55:08.885560 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 130.138227455569 Dec: -45.0446854430611 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 10
Image Trigger?: YES
Rate S/N Ratio: 0 [ if not an image trigger ]
Image S/N Ratio: 10
Flight Position: [ source = BAT ]
RA: 130.138227455569 Dec: -45.0446854430611 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 130.112409789998 Dec: -45.0224846519555 [deg; J2000]
{ 08h 40m 27.0s , -45d 01' 20.9" }
+/- 2.62610028922726 [arcmin] (estimated 90% radius based on SNR)
+/- 1.34392657561709 [arcmin] (formal 1-sigma fit error)
SNR: 7.65776838041155
Angular difference between Flight and Ground position is 1.724163 arcmin
Partial Coding Fraction: 0.59375 [ 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 0.511727 0.498171 0.089798 0.051954
0.069618 0.065835 0.059452 0.055309 [error]
Peak 0.511727 0.498171 0.089798 0.051954
0.069618 0.065835 0.059452 0.055309 [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 1.83e-07 1.87e-07 1.34e-07 1.54e-07 5.64e-07 6.64e-07 erg/cm2
Error 3.60e-08 3.39e-08 4.84e-08 1.05e-07 1.14e-07 1.75e-07 erg/cm2
Peak flux Power-law 9.40e-02 5.35e-02 1.93e-02 9.12e-03 1.72e-01 1.76e-01 ph/cm2/s
Error 1.89e-02 9.39e-03 6.70e-03 5.79e-03 2.73e-02 2.82e-02 ph/cm2/s
Fluence Cutoff-PL 1.68e-07 2.23e-07 8.54e-08 5.91e-09 4.82e-07 4.82e-07 erg/cm2
Error 4.10e-08 4.83e-08 6.18e-08 5.51e-08 1.08e-07 1.24e-07 erg/cm2
Peak flux Cutoff-PL 8.49e-02 6.40e-02 1.32e-02 4.99e-04 1.63e-01 1.63e-01 ph/cm2/s
Error 2.18e-02 1.36e-02 8.68e-03 3.53e-03 2.77e-02 2.78e-02 ph/cm2/s
Fluence Band 1.68e-07 2.21e-07 8.95e-08 2.25e-08 4.94e-07 5.10e-07 erg/cm2
Error 4.00e-08 4.29e-08 3.40e-08 7.48e-08 1.13e-07 1.64e-07 erg/cm2
Peak flux Band 8.56e-02 6.39e-02 1.37e-02 1.61e-03 1.64e-01 1.65e-01 ph/cm2/s
Error 2.15e-02 1.14e-02 6.98e-03 3.45e-03 2.64e-02 2.89e-02 ph/cm2/s
=== Time-averaged spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 2.475 0.349 - - 8.87e-04 2.35e-04 54.105 57
CPL 0.346 2.211 26.6 17.1 2.08e-02 7.01e-01 50.709 0
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 2.475 0.349 - - 8.87e-04 2.35e-04 54.105 57
CPL 0.346 2.211 26.6 17.1 2.08e-02 7.01e-01 50.709 0
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
130.1124 -45.0225 0.0252 35.0 12.5 1.2303 7.7 TRIG_00325461
------------------------------------------
Foreground time interval of the image:
0.000 64.000 (delta_t = 64.000 [sec])
Background time interval of the image:
Lightcurves
Notes:
- 1) All plots contain as much data as has been downloaded to date.
- 2) Multiple plots of different time binning/intervals are shown to cover all scenarios of short/long GRBs, rate/image triggers, and real/false positives.
- 3) 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.
- 4) 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.
- 5) 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 64.000 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.47482 ( -0.326297 0.372603 )
Norm@50keV : 8.872831E-04 ( -2.351645E-04 2.343097E-04) )
------------------------------------------------------------
Chi-Squared = 54.10530 using 59 PHA bins.
Reduced chi-squared = 0.9492159 for 57 degrees of freedom
Null hypothesis probability = 0.584
Photon flux (15-150 keV) in 64.00 sec: 0.171650 ( -0.027255 0.027258 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.64015e-07 ( -1.10369e-07 1.16747e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.000 sec. to 64.000 sec.
Parameters : value lower 90% higher 90%
Photon index: 0.346046 ( -2.77327 1.64807 )
Epeak [keV] : 26.5894 ( -26.5794 7.58624 )
Norm@50keV : 2.081205E-02 ( -1.960236E-02 1.38213 )
------------------------------------------------------------
Chi-Squared = 50.70944 using 59 PHA bins.
but latest trial 1.99411 gives Chi-Squared = 9.20911
but latest trial 1.343552E-03 gives Chi-Squared = 4.22850
Reduced chi-squared = 0.9055257 for 56 degrees of freedom
Null hypothesis probability = 0.675
Photon flux (15-150 keV) in 64.00 sec: 0.162527 ( -0.027513 0.027885 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.82085e-07 ( -9.43475e-08 1.21965e-07 ) ergs/cm2
Band function
Time interval is from 0.000 sec. to 64.000 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.58169 ( -4.568100E-04 14.9995 )
beta : -1.83088 ( -0.372911 0.325792 )
Epeak [keV] : 7.89177 ( -7.79177 9992.11 )
Norm@50keV : 2.636071E-03 ( -3.201070E-02 3.181466E-02) )
------------------------------------------------------------
Chi-Squared = 65.33875 using 59 PHA bins.
Reduced chi-squared = 1.187977 for 55 degrees of freedom
Null hypothesis probability = 0.160
Photon flux (15-150 keV) in 64.00 sec: 0.163558 ( -0.026979 0.025813 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.93998e-07 ( -1.05649e-07 1.20461e-07 ) ergs/cm2
Peak spectrum fit using the pre-slew DRM
Power-law model
Time interval is from 0.000 sec. to 64.000 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.47482 ( -0.326297 0.372603 )
Norm@50keV : 8.872831E-04 ( -2.351645E-04 2.343097E-04) )
------------------------------------------------------------
Chi-Squared = 54.10530 using 59 PHA bins.
Reduced chi-squared = 0.9492159 for 57 degrees of freedom
Null hypothesis probability = 0.584
Photon flux (15-150 keV) in 64.00 sec: 0.171650 ( -0.027255 0.027258 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.64015e-07 ( -1.10369e-07 1.16747e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.000 sec. to 64.000 sec.
Parameters : value lower 90% higher 90%
Photon index: 0.346046 ( -2.77327 1.64807 )
Epeak [keV] : 26.5894 ( -26.5794 7.58624 )
Norm@50keV : 2.081205E-02 ( -1.960236E-02 1.38213 )
------------------------------------------------------------
Chi-Squared = 50.70944 using 59 PHA bins.
but latest trial 1.99411 gives Chi-Squared = 9.20911
but latest trial 1.343552E-03 gives Chi-Squared = 4.22850
Reduced chi-squared = 0.9055257 for 56 degrees of freedom
Null hypothesis probability = 0.675
Photon flux (15-150 keV) in 64.00 sec: 0.162527 ( -0.027513 0.027885 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.82085e-07 ( -9.43475e-08 1.21965e-07 ) ergs/cm2
Band function
Time interval is from 0.000 sec. to 64.000 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.58169 ( -4.568100E-04 14.9995 )
beta : -1.83088 ( -0.372911 0.325792 )
Epeak [keV] : 7.89177 ( -7.79177 9992.11 )
Norm@50keV : 2.636071E-03 ( -3.201070E-02 3.181466E-02) )
------------------------------------------------------------
Chi-Squared = 65.33875 using 59 PHA bins.
Reduced chi-squared = 1.187977 for 55 degrees of freedom
Null hypothesis probability = 0.160
Photon flux (15-150 keV) in 64.00 sec: 0.163558 ( -0.026979 0.025813 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.93998e-07 ( -1.05649e-07 1.20461e-07 ) ergs/cm2
Plot creation:
Sun Sep 21 23:14:59 EDT 2008