batgrbproduct Analysis for Trigger=307256
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 Mar 23 06:22:52 EDT 2008
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger307256/GCN5_download_cron
======================================================================
Trigger: 00307256 Segment: 000
BAT Trigger Time: 227885058.624 [s; MET]
Trigger Stop: 227885059.648 [s; MET]
UTC: 2008-03-22T13:24:15.962360 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 356.615296223207 Dec: -30.0913182413444 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 6.02
Image Trigger?: NO
Rate S/N Ratio: 11 [ if not an image trigger ]
Image S/N Ratio: 6.02
Flight Position: [ source = BAT ]
RA: 356.615296223207 Dec: -30.0913182413444 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 356.67446350238 Dec: -30.0856837364644 [deg; J2000]
{ 23h 46m 41.9s , -30d 05' 08.5" }
+/- 4.24964236212713 [arcmin] (estimated 90% radius based on SNR)
+/- 2.16212434120708 [arcmin] (formal 1-sigma fit error)
SNR: 3.85010096985303
RA = 23h 46m 41.9s (356.674464 deg.)
Dec = -30d 5' 8" (-30.085684 deg.)
Angular difference between Flight and Ground position is 3.090225 arcmin
Partial Coding Fraction: 0.546875 [ including projection effects ]
Duration
T90: 1.02399998903275 +/-
Measured from: 0
to: 1.02399998903275 [s; relative to TRIGTIME]
T50: 1.02399998903275 +/-
Measured from: 0
to: 1.02399998903275 [s; relative to TRIGTIME]
WARNING: battblocks failed. Used TDRSS fore/background intervals
Fluence
Peak Flux (peak 1.02399998903275 second)
Measured from: 0
to: 1.02399998903275 [s; relative to TRIGTIME]
Total Fluence
Measured from: 0
to: 1.02399998903275 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.001648 0.009084 0.022179 0.015892
0.006860 0.007296 0.007179 0.007679 [error]
Peak 0.001648 0.009084 0.022179 0.015892
0.006860 0.007296 0.007179 0.007679 [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 1.05e-09 4.43e-09 1.55e-08 1.87e-07 4.44e-08 2.47e-07 erg/cm2
Error 1.48e-09 2.87e-09 1.10e-08 3.04e-07 1.85e-08 3.06e-07 erg/cm2
Peak flux Power-law 3.26e-02 7.24e-02 1.27e-01 5.18e-01 3.46e-01 7.50e-01 ph/cm2/s
Error 4.61e-02 6.85e-02 9.07e-02 5.37e-01 1.62e-01 5.02e-01 ph/cm2/s
Fluence Cutoff-PL 5.36e-10 4.04e-09 1.83e-08 5.92e-08 4.46e-08 1.91e-07 erg/cm2
Error 1.38e-09 4.20e-09 9.11e-09 2.29e-07 1.95e-08 0.00e+00 erg/cm2
Peak flux Cutoff-PL 1.60e-02 6.43e-02 1.49e-01 2.18e-01 3.37e-01 4.49e-01 ph/cm2/s
Error 4.28e-02 6.92e-02 7.63e-02 5.76e-01 1.55e-01 4.15e-01 ph/cm2/s
Fluence Band 5.52e-10 4.05e-09 1.82e-08 6.00e-08 4.46e-08 1.10e-07 erg/cm2
Error 1.37e-09 4.19e-09 9.42e-09 2.26e-07 1.97e-08 2.40e-07 erg/cm2
Peak flux Band 1.60e-02 6.43e-02 1.50e-01 2.17e-01 3.37e-01 4.46e-01 ph/cm2/s
Error 4.28e-02 6.91e-02 7.85e-02 5.77e-01 1.56e-01 5.49e-01 ph/cm2/s
=== Time-averaged spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 0.191 0.910 - - 2.73e-03 2.19e-03 58.211 0
CPL -1.360 1.957 159.9 5000.0 8.52e-03 4.17e-02 57.740 56
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 0.191 0.910 - - 2.73e-03 2.19e-03 58.211 0
CPL -1.360 1.957 159.9 5000.0 8.52e-03 4.17e-02 57.740 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 1.024 0.000 1.024
T90 1.024 0.000 1.024
T50 1.024 0.000 1.024
Peak 1.024 0.000 1.024
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
356.6745 -30.0857 0.0501 32.8 -46.4 0.0562 3.9 TRIG_00307256
------------------------------------------
Foreground time interval of the image:
0.000 1.024 (delta_t = 1.024 [sec])
Background time interval of the image:
-35.523 -10.624 (delta_t = 24.899 [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 0.000 sec. to 1.024 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.190799 ( -1.02064 0.798499 )
Norm@50keV : 2.727079E-03 ( -2.727079E-03 1.645660E-03) )
------------------------------------------------------------
Chi-Squared = 58.21125 using 59 PHA bins.
but latest trial -1.84015 gives Chi-Squared = 2.78027
Reduced chi-squared = 1.021250 for 57 degrees of freedom
Null hypothesis probability = 0.431
Photon flux (15-150 keV) in 1.024 sec: 0.346351 ( -0.157367 0.1658 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.44153e-08 ( -1.84483e-08 1.84852e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.000 sec. to 1.024 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.36000 ( -1.64000 2.27405 )
Epeak [keV] : 159.906 ( -159.896 9840.09 )
Norm@50keV : 8.521061E-03 ( -8.521060E-03 7.492218E-02) )
------------------------------------------------------------
Chi-Squared = 57.73982 using 59 PHA bins.
Reduced chi-squared = 1.031068 for 56 degrees of freedom
Null hypothesis probability = 0.411
Photon flux (15-150 keV) in 1.024 sec: 0.337403 ( -0.145994 0.163419 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.45818e-08 ( -1.9924e-08 1.91344e-08 ) ergs/cm2
Band function
Time interval is from 0.000 sec. to 1.024 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.391931 ( -9.60807 5.39193 )
beta : -0.189385 ( -0.801004 1.01405 )
Epeak [keV] : 19.2809 ( -19.1809 9980.72 )
Norm@50keV : 4.098692E-03 ( -4.098692E-03 21279.0 )
------------------------------------------------------------
Chi-Squared = 58.21130 using 59 PHA bins.
Reduced chi-squared = 1.058387 for 55 degrees of freedom
Null hypothesis probability = 0.358
Photon flux (15-150 keV) in 1.024 sec: 0.337259 ( -0.147148 0.16413 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.45889e-08 ( -2.0259e-08 1.9098e-08 ) ergs/cm2
Peak spectrum fit using the pre-slew DRM
Power-law model
Time interval is from 0.000 sec. to 1.024 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.190799 ( -1.02064 0.798499 )
Norm@50keV : 2.727079E-03 ( -2.727079E-03 1.645660E-03) )
------------------------------------------------------------
Chi-Squared = 58.21125 using 59 PHA bins.
but latest trial -1.84015 gives Chi-Squared = 2.78027
Reduced chi-squared = 1.021250 for 57 degrees of freedom
Null hypothesis probability = 0.431
Photon flux (15-150 keV) in 1.024 sec: 0.346351 ( -0.157367 0.1658 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.44153e-08 ( -1.84483e-08 1.84852e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.000 sec. to 1.024 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.36000 ( -1.64000 2.27405 )
Epeak [keV] : 159.906 ( -159.896 9840.09 )
Norm@50keV : 8.521061E-03 ( -8.521060E-03 7.492218E-02) )
------------------------------------------------------------
Chi-Squared = 57.73982 using 59 PHA bins.
Reduced chi-squared = 1.031068 for 56 degrees of freedom
Null hypothesis probability = 0.411
Photon flux (15-150 keV) in 1.024 sec: 0.337403 ( -0.145994 0.163419 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.45818e-08 ( -1.9924e-08 1.91344e-08 ) ergs/cm2
Band function
Time interval is from 0.000 sec. to 1.024 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.391931 ( -9.60807 5.39193 )
beta : -0.189385 ( -0.801004 1.01405 )
Epeak [keV] : 19.2809 ( -19.1809 9980.72 )
Norm@50keV : 4.098692E-03 ( -4.098692E-03 21279.0 )
------------------------------------------------------------
Chi-Squared = 58.21130 using 59 PHA bins.
Reduced chi-squared = 1.058387 for 55 degrees of freedom
Null hypothesis probability = 0.358
Photon flux (15-150 keV) in 1.024 sec: 0.337259 ( -0.147148 0.16413 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.45889e-08 ( -2.0259e-08 1.9098e-08 ) ergs/cm2
Plot creation:
Sun Mar 23 06:39:25 EDT 2008