batgrbproduct Analysis for Trigger=306858
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): Thu Mar 20 11:43:51 EDT 2008
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger306858/GCN5_download_cron
======================================================================
Trigger: 00306858 Segment: 000
BAT Trigger Time: 227680661.12 [s; MET]
Trigger Stop: 227680662.528 [s; MET]
UTC: 2008-03-20T04:37:38.464040 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 177.780563457759 Dec: 57.1439944141214 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 7.64
Image Trigger?: NO
Rate S/N Ratio: 9.9498743710662 [ if not an image trigger ]
Image S/N Ratio: 7.64
Flight Position: [ source = BAT ]
RA: 177.780563457759 Dec: 57.1439944141214 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 177.763052801393 Dec: 57.1618227872438 [deg; J2000]
{ 11h 51m 03.1s , +57d 09' 42.6" }
+/- 1.75892485441492 [arcmin] (estimated 90% radius based on SNR)
+/- 0.745365730993733 [arcmin] (formal 1-sigma fit error)
SNR: 13.575790102407
RA = 11h 51m 3.1s (177.763053 deg.)
Dec = 57d 9' 43" (57.161823 deg.)
Angular difference between Flight and Ground position is 1.212027 arcmin
Partial Coding Fraction: 0.9375 [ including projection effects ]
Duration
T90: 13.8440000116825 +/- 1.91739093029525
Measured from: -1.14800000190735
to: 12.6960000097752 [s; relative to TRIGTIME]
T50: 6.89599999785423 +/- 2.99864033646295
Measured from: 0.428000003099442
to: 7.32400000095367 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 0.15200001001358
to: 1.15200001001358 [s; relative to TRIGTIME]
Total Fluence
Measured from: -1.67199999094009
to: 13.8479999899864 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.151911 0.177445 0.106469 0.042777
0.018717 0.019023 0.017380 0.015951 [error]
Peak 0.022030 0.026272 0.018540 0.006561
0.004962 0.005051 0.004576 0.004041 [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 4.54e-08 7.38e-08 9.06e-08 2.19e-07 2.72e-07 4.28e-07 erg/cm2
Error 8.53e-09 8.87e-09 1.70e-08 8.55e-08 3.95e-08 1.01e-07 erg/cm2
Peak flux Power-law 2.10e-01 1.92e-01 1.21e-01 1.17e-01 5.72e-01 6.40e-01 ph/cm2/s
Error 6.81e-02 4.10e-02 3.70e-02 7.06e-02 1.21e-01 1.39e-01 ph/cm2/s
Fluence Cutoff-PL 4.50e-08 7.49e-08 9.07e-08 1.77e-07 2.69e-07 3.62e-07 erg/cm2
Error 9.20e-09 1.09e-08 1.75e-08 1.01e-07 4.40e-08 1.48e-07 erg/cm2
Peak flux Cutoff-PL 1.91e-01 2.07e-01 1.27e-01 5.58e-02 5.60e-01 5.80e-01 ph/cm2/s
Error 7.95e-02 5.24e-02 4.23e-02 9.30e-02 1.24e-01 1.58e-01 ph/cm2/s
Fluence Band 4.43e-08 7.57e-08 8.89e-08 2.01e-07 2.68e-07 4.13e-07 erg/cm2
Error 8.98e-09 1.13e-08 1.81e-08 1.51e-07 4.13e-08 1.59e-07 erg/cm2
Peak flux Band 1.91e-01 2.07e-01 1.27e-01 5.60e-02 5.60e-01 5.80e-01 ph/cm2/s
Error 7.95e-02 5.25e-02 4.23e-02 9.30e-02 1.24e-01 1.59e-01 ph/cm2/s
=== Time-averaged spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.704 0.224 - - 1.89e-03 2.59e-04 37.715 57
CPL 1.484 0.637 106.1 0.0 2.49e-03 2.73e-03 37.698 56
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.664 0.376 - - 4.36e-03 1.03e-03 54.242 57
CPL 0.985 1.567 70.7 4981.0 1.00e-02 4.91e-02 53.541 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: 4.992000 sec.
T50 in the 50-300 keV band: 2.496000 sec.
=== Table of the duration information ==
Value tstart tstop
T100 15.520 -1.672 13.848
T90 13.844 -1.148 12.696
T50 6.896 0.428 7.324
Peak 1.000 0.152 1.152
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
177.7631 +57.1618 0.0142 22.1 -178.3 0.4667 13.6 TRIG_00306858
------------------------------------------
Foreground time interval of the image:
-1.672 13.848 (delta_t = 15.520 [sec])
Background time interval of the image:
-119.120 -56.553 (delta_t = 62.567 [sec])
-55.120 -1.672 (delta_t = 53.448 [sec])
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.
Time averaged spectrum fit using the pre-slew DRM
Power-law model
Time interval is from -1.672 sec. to 13.848 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.70370 ( -0.220718 0.227970 )
Norm@50keV : 1.893747E-03 ( -2.616640E-04 2.556347E-04) )
------------------------------------------------------------
Chi-Squared = 37.71481 using 59 PHA bins.
Reduced chi-squared = 0.6616632 for 57 degrees of freedom
Null hypothesis probability = 0.977
Photon flux (15-150 keV) in 15.52 sec: 0.251836 ( -0.030359 0.030377 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.72047e-07 ( -3.907e-08 3.99361e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -1.672 sec. to 13.848 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.48420 ( -0.827903 0.446229 )
Epeak [keV] : 106.128 ( )
Norm@50keV : 2.487159E-03 ( -3.895182E-04 5.069171E-03) )
------------------------------------------------------------
Chi-Squared = 37.69807 using 59 PHA bins.
Reduced chi-squared = 0.6731799 for 56 degrees of freedom
Null hypothesis probability = 0.971
Photon flux (15-150 keV) in 15.52 sec: 0.250703 ( -0.031334 0.030761 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.68893e-07 ( -4.54208e-08 4.26443e-08 ) ergs/cm2
Band function
Time interval is from -1.672 sec. to 13.848 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.13998 ( -8.86002 5.76033 )
beta : -1.76643 ( -8.23357 0.268783 )
Epeak [keV] : 46.6659 ( -46.5659 620.361 )
Norm@50keV : 4.556782E-03 ( -9.693463E-02 167.401 )
------------------------------------------------------------
Chi-Squared = 37.37991 using 59 PHA bins.
Reduced chi-squared = 0.6796348 for 55 degrees of freedom
Null hypothesis probability = 0.967
Photon flux (15-150 keV) in 15.52 sec: 0.250659 ( -0.031327 0.031118 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.6847e-07 ( -4.24239e-08 4.01208e-08 ) ergs/cm2
Peak spectrum fit using the pre-slew DRM
Power-law model
Time interval is from 0.152 sec. to 1.152 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.66408 ( -0.362697 0.388789 )
Norm@50keV : 4.357448E-03 ( -1.050367E-03 1.014299E-03) )
------------------------------------------------------------
Chi-Squared = 54.24152 using 59 PHA bins.
Reduced chi-squared = 0.9516057 for 57 degrees of freedom
Null hypothesis probability = 0.579
Photon flux (15-150 keV) in 1.000 sec: 0.571637 ( -0.121158 0.121208 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.04626e-08 ( -1.00535e-08 1.03786e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.152 sec. to 1.152 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.984948 ( -1.88965 1.24350 )
Epeak [keV] : 70.7444 ( -32.6617 9929.26 )
Norm@50keV : 1.002784E-02 ( -1.002784E-02 8.822639E-02) )
------------------------------------------------------------
Chi-Squared = 53.54062 using 59 PHA bins.
Reduced chi-squared = 0.9560825 for 56 degrees of freedom
Null hypothesis probability = 0.569
Photon flux (15-150 keV) in 1.000 sec: 0.560349 ( -0.123941 0.12345 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.86738e-08 ( -1.05136e-08 1.10276e-08 ) ergs/cm2
Band function
Time interval is from 0.152 sec. to 1.152 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.990960 ( -9.00904 1.65299 )
beta : -8.59972 ( -1.40028 7.24727 )
Epeak [keV] : 71.0308 ( -31.2538 9928.97 )
Norm@50keV : 9.946347E-03 ( -9.946347E-03 8.838486E-02) )
------------------------------------------------------------
Chi-Squared = 53.54068 using 59 PHA bins.
Reduced chi-squared = 0.9734668 for 55 degrees of freedom
Null hypothesis probability = 0.531
Photon flux (15-150 keV) in 1.000 sec: 0.560444 ( -0.124014 0.123371 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.86443e-08 ( -1.05052e-08 1.10261e-08 ) ergs/cm2
Plot creation:
Thu Mar 20 12:03:39 EDT 2008