batgrbproduct Analysis for Trigger=301981
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): Tue Jan 29 14:46:54 EST 2008
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger301981/GCN5_download_cron
======================================================================
Trigger: 00301981 Segment: 000
BAT Trigger Time: 223279608 [s; MET]
Trigger Stop: 223279672 [s; MET]
UTC: 2008-01-29T06:06:45.464120 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 105.280011758568 Dec: -7.82688688603851 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 7.51
Image Trigger?: YES
Rate S/N Ratio: 0 [ if not an image trigger ]
Image S/N Ratio: 7.51
Flight Position: [ source = BAT ]
RA: 105.280011758568 Dec: -7.82688688603851 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 105.296612320819 Dec: -7.84009445543375 [deg; J2000]
{ 07h 01m 11.2s , -07d 50' 24.3" }
+/- 2.36791209199961 [arcmin] (estimated 90% radius based on SNR)
+/- 1.35721212399852 [arcmin] (formal 1-sigma fit error)
SNR: 8.87790340182239
RA = 7h 1m 11.2s (105.296612 deg.)
Dec = -7d 50' 24" (-7.840094 deg.)
Angular difference between Flight and Ground position is 1.265558 arcmin
Partial Coding Fraction: 0.46875 [ including projection effects ]
Duration
T90: 48 +/- 35.7770876399966
Measured from: -15
to: 33 [s; relative to TRIGTIME]
T50: 16 +/- 22.6274169979695
Measured from: 1
to: 17 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 24.5
to: 25.5 [s; relative to TRIGTIME]
Total Fluence
Measured from: -15
to: 49 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.264492 0.451564 0.452260 0.059619
0.065235 0.065519 0.057686 0.049145 [error]
Peak 0.013631 0.176582 0.176871 0.018735
0.032923 0.032952 0.029523 0.024981 [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 9.91e-08 2.02e-07 3.21e-07 1.13e-06 8.91e-07 1.76e-06 erg/cm2
Error 2.85e-08 3.47e-08 5.36e-08 4.30e-07 1.36e-07 4.57e-07 erg/cm2
Peak flux Power-law 4.39e-02 6.12e-02 6.31e-02 1.19e-01 2.06e-01 2.87e-01 ph/cm2/s
Error 2.22e-02 1.95e-02 1.38e-02 5.45e-02 5.08e-02 6.41e-02 ph/cm2/s
Fluence Cutoff-PL 9.56e-08 2.05e-07 3.27e-07 9.22e-07 8.86e-07 1.51e-06 erg/cm2
Error 3.29e-08 3.87e-08 4.78e-08 6.46e-07 1.36e-07 6.70e-07 erg/cm2
Peak flux Cutoff-PL 2.75e-02 6.34e-02 7.57e-02 4.44e-02 1.96e-01 2.11e-01 ph/cm2/s
Error 2.43e-02 2.33e-02 2.01e-02 6.48e-02 5.09e-02 8.18e-02 ph/cm2/s
Fluence Band 9.21e-08 2.11e-07 3.21e-07 1.05e-06 8.83e-07 1.62e-06 erg/cm2
Error 2.93e-08 3.62e-08 5.94e-08 6.66e-07 1.39e-07 5.72e-07 erg/cm2
Peak flux Band 2.62e-02 6.94e-02 7.15e-02 7.58e-02 1.89e-01 2.44e-01 ph/cm2/s
Error 2.64e-02 1.83e-02 6.75e-02 4.70e-02 8.23e-02 0.00e+00 ph/cm2/s
=== Time-averaged spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.334 0.258 - - 1.42e-03 2.06e-04 52.483 57
CPL 1.042 1.315 180.6 0.0 1.95e-03 2.12e-03 52.488 0
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 0.956 0.384 - - 1.79e-03 4.35e-04 61.146 57
CPL -0.577 2.056 102.3 4965.2 7.77e-03 3.01e-02 58.961 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: 47.296000 sec.
T50 in the 50-300 keV band: 19.264000 sec.
=== Table of the duration information ==
Value tstart tstop
T100 64.000 -15.000 49.000
T90 48.000 -15.000 33.000
T50 16.000 1.000 17.000
Peak 1.000 24.500 25.500
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
105.2966 -7.8401 0.0217 41.5 176.8 1.2057 8.9 TRIG_00301981
------------------------------------------
Foreground time interval of the image:
-15.000 49.000 (delta_t = 64.000 [sec])
Background time interval of the image:
-239.000 -15.000 (delta_t = 224.000 [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 -15.000 sec. to 49.000 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.33401 ( -0.261115 0.254030 )
Norm@50keV : 1.420038E-03 ( -2.061327E-04 2.056808E-04) )
------------------------------------------------------------
Chi-Squared = 52.48283 using 59 PHA bins.
Reduced chi-squared = 0.9207515 for 57 degrees of freedom
Null hypothesis probability = 0.645
Photon flux (15-150 keV) in 64.00 sec: 0.170522 ( -0.026687 0.026858 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.90957e-07 ( -1.35405e-07 1.35725e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -15.000 sec. to 49.000 sec.
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.04196 ( -1.01272 1.61757 )
Epeak [keV] : 180.626 ( )
Norm@50keV : 1.947215E-03 ( -3.214902E-04 3.917618E-03) )
------------------------------------------------------------
Chi-Squared = 52.48822 using 59 PHA bins.
but latest trial 2.65954 gives Chi-Squared = 1.99231
Reduced chi-squared = 0.9372897 for 56 degrees of freedom
Null hypothesis probability = 0.609
Photon flux (15-150 keV) in 64.00 sec: 0.169641 ( -0.027421 0.027356 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.864e-07 ( -1.32371e-07 1.38733e-07 ) ergs/cm2
Band function
Time interval is from -15.000 sec. to 49.000 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.822662 ( -9.17734 2.74938 )
beta : -1.40272 ( -8.59728 0.321726 )
Epeak [keV] : 89.4767 ( -89.3767 9910.52 )
Norm@50keV : 2.812024E-03 ( -2.812024E-03 52.9000 )
------------------------------------------------------------
Chi-Squared = 52.31753 using 59 PHA bins.
Reduced chi-squared = 0.9512278 for 55 degrees of freedom
Null hypothesis probability = 0.578
Photon flux (15-150 keV) in 64.00 sec: 0.168752 ( -0.028177 0.027546 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.83456e-07 ( -1.40026e-07 1.37965e-07 ) ergs/cm2
Peak spectrum fit using the pre-slew DRM
Power-law model
Time interval is from 17.000 sec. to 33.000 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.956200 ( -0.406454 0.362111 )
Norm@50keV : 1.793693E-03 ( -4.417817E-04 4.278043E-04) )
------------------------------------------------------------
Chi-Squared = 61.14580 using 59 PHA bins.
Reduced chi-squared = 1.072733 for 57 degrees of freedom
Null hypothesis probability = 0.329
Photon flux (15-150 keV) in 16.00 sec: 0.206128 ( -0.050225 0.051388 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.15307e-07 ( -6.93696e-08 6.9472e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 17.000 sec. to 33.000 sec.
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.576883 ( -2.42312 1.68965 )
Epeak [keV] : 102.287 ( -32.6219 9897.71 )
Norm@50keV : 7.765065E-03 ( -7.765065E-03 5.253498E-02) )
------------------------------------------------------------
Chi-Squared = 58.96088 using 59 PHA bins.
but latest trial 1.11171 gives Chi-Squared = 2.82765
Reduced chi-squared = 1.052873 for 56 degrees of freedom
Null hypothesis probability = 0.368
Photon flux (15-150 keV) in 16.00 sec: 0.195950 ( -0.049692 0.052148 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.0405e-07 ( -7.45584e-08 7.32816e-08 ) ergs/cm2
Band function
Time interval is from 17.000 sec. to 33.000 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : 0.749299 ( -3.70020 1.89445 )
beta : -2.06180 ( -8.49549 2.38895 )
Epeak [keV] : 95.0502 ( -29.2388 525.470 )
Norm@50keV : 9.496225E-03 ( -0.827597 0.598429 )
------------------------------------------------------------
Chi-Squared = 58.89336 using 59 PHA bins.
Reduced chi-squared = 1.070788 for 55 degrees of freedom
Null hypothesis probability = 0.335
Photon flux (15-150 keV) in 16.00 sec: 0.188770 ( -0.042434 0.051611 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.0385e-07 ( -7.42688e-08 7.316e-08 ) ergs/cm2
Plot creation:
Tue Jan 29 15:16:10 EST 2008