batgrbproduct Analysis for Trigger=278903
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 Dec 13 21:07:44 EST 2007
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger278903/GCN5_download_cron
======================================================================
Trigger: 00278903 Segment: 000
BAT Trigger Time: 200371709.248 [s; MET]
Trigger Stop: 200371710.272 [s; MET]
UTC: 2007-05-09T02:48:27.305440 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 237.926549002769 Dec: -78.6806906520622 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 8.66
Image Trigger?: NO
Rate S/N Ratio: 13.6014705087354 [ if not an image trigger ]
Image S/N Ratio: 8.66
Flight Position: [ source = BAT ]
RA: 237.926549002769 Dec: -78.6806906520622 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 237.899598851173 Dec: -78.6537885459482 [deg; J2000]
{ 15h 51m 35.9s , -78d 39' 13.6" }
+/- 1.74158115427165 [arcmin] (estimated 90% radius based on SNR)
+/- 0.676098185400007 [arcmin] (formal 1-sigma fit error)
SNR: 13.7693383115703
RA = 15h 51m 35.9s (237.899599 deg.)
Dec = -78d 39' 14" (-78.653789 deg.)
Angular difference between Flight and Ground position is 1.645105 arcmin
Partial Coding Fraction: 0.9296875 [ including projection effects ]
Duration
T90: 7.69600000977516 +/- 1.22247781199445
Measured from: -0.88400000333786
to: 6.8120000064373 [s; relative to TRIGTIME]
T50: 3.53600001335144 +/- 1.04749606389055
Measured from: 0.131999999284744
to: 3.66800001263618 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: -0.30799999833107
to: 0.69200000166893 [s; relative to TRIGTIME]
Total Fluence
Measured from: -1.11599999666214
to: 7.86800000071526 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.174385 0.142022 0.054941 0.008312
0.015011 0.014722 0.012482 0.010695 [error]
Peak 0.027284 0.034818 0.022083 0.005322
0.005157 0.005226 0.004291 0.003645 [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 5.08e-08 5.67e-08 4.51e-08 5.95e-08 1.75e-07 2.12e-07 erg/cm2
Error 7.73e-09 7.07e-09 1.12e-08 2.85e-08 2.54e-08 4.29e-08 erg/cm2
Peak flux Power-law 2.46e-01 2.27e-01 1.45e-01 1.43e-01 6.77e-01 7.61e-01 ph/cm2/s
Error 6.81e-02 4.06e-02 3.51e-02 6.85e-02 1.19e-01 1.35e-01 ph/cm2/s
Fluence Cutoff-PL 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 Cutoff-PL 1.97e-01 2.57e-01 1.57e-01 4.26e-02 6.44e-01 6.53e-01 ph/cm2/s
Error 8.62e-02 5.38e-02 4.23e-02 7.42e-02 1.25e-01 1.44e-01 ph/cm2/s
Fluence Band 5.10e-08 5.78e-08 4.18e-08 4.79e-08 1.69e-07 2.00e-07 erg/cm2
Error 8.38e-09 8.15e-09 1.18e-08 2.77e-08 4.66e-08 0.00e+00 erg/cm2
Peak flux Band 1.97e-01 2.57e-01 1.57e-01 4.27e-02 6.44e-01 6.55e-01 ph/cm2/s
Error 8.19e-02 4.80e-02 3.71e-02 4.66e-02 1.26e-01 1.01e-01 ph/cm2/s
=== Time-averaged spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 2.329 0.252 - - 2.02e-03 3.64e-04 42.224 57
CPL 1.947 0.000 5.2 0.0 3.47e-03 0.00e+00 42.340 56
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.646 0.305 - - 5.19e-03 9.82e-04 56.605 57
CPL 0.318 1.745 60.9 4977.4 2.53e-02 1.48e-01 54.015 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 8.984 -1.116 7.868
T90 7.696 -0.884 6.812
T50 3.536 0.132 3.668
Peak 1.000 -0.308 0.692
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
237.8996 -78.6538 0.0141 13.9 47.3 0.3769 13.8 TRIG_00278903
------------------------------------------
Foreground time interval of the image:
-1.116 7.868 (delta_t = 8.984 [sec])
Background time interval of the image:
-239.248 -1.116 (delta_t = 238.132 [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 -1.116 sec. to 7.868 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.32920 ( -0.242126 0.261511 )
Norm@50keV : 2.023483E-03 ( -3.673559E-04 3.605646E-04) )
------------------------------------------------------------
Chi-Squared = 42.22420 using 59 PHA bins.
Reduced chi-squared = 0.7407754 for 57 degrees of freedom
Null hypothesis probability = 0.928
Photon flux (15-150 keV) in 8.984 sec: 0.359456 ( -0.04115 0.04115 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.74674e-07 ( -2.48857e-08 2.5873e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -1.116 sec. to 7.868 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.94711 ( )
Epeak [keV] : 5.19980 ( )
Norm@50keV : 3.469836E-03 ( )
------------------------------------------------------------
Chi-Squared = 42.33953 using 59 PHA bins.
Reduced chi-squared = 0.7560630 for 56 degrees of freedom
Null hypothesis probability = 0.911
Photon flux (15-150 keV) in 8.984 sec: ( ) ph/cm2/s
Energy fluence (15-150 keV) : 0 ( 0 0 ) ergs/cm2
Band function
Time interval is from -1.116 sec. to 7.868 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.95265 ( -8.04735 6.95265 )
beta : -9.19066 ( -7.59263 0.304963 )
Epeak [keV] : 4.20516 ( -2.05499 26.7990 )
Norm@50keV : 3.605985E-03 ( -1.447830E-03 2.768256E-02) )
------------------------------------------------------------
Chi-Squared = 42.39827 using 59 PHA bins.
Reduced chi-squared = 0.7708775 for 55 degrees of freedom
Null hypothesis probability = 0.893
Photon flux (15-150 keV) in 8.984 sec: 0.357647 ( -0.042635 0.042321 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.69283e-07 ( -2.62791e-08 2.91827e-08 ) ergs/cm2
Peak spectrum fit using the pre-slew DRM
Power-law model
Time interval is from -0.308 sec. to 0.692 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.64585 ( -0.297831 0.312209 )
Norm@50keV : 5.193306E-03 ( -9.922581E-04 9.713233E-04) )
------------------------------------------------------------
Chi-Squared = 56.60492 using 59 PHA bins.
Reduced chi-squared = 0.9930688 for 57 degrees of freedom
Null hypothesis probability = 0.490
Photon flux (15-150 keV) in 1.000 sec: 0.677175 ( -0.119185 0.119344 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.83186e-08 ( -9.6554e-09 9.8693e-09 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.308 sec. to 0.692 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.318140 ( -2.10283 1.38813 )
Epeak [keV] : 60.9362 ( -15.6393 9939.06 )
Norm@50keV : 2.532824E-02 ( -2.532824E-02 0.270261 )
------------------------------------------------------------
Chi-Squared = 54.01457 using 59 PHA bins.
Reduced chi-squared = 0.9645458 for 56 degrees of freedom
Null hypothesis probability = 0.550
Photon flux (15-150 keV) in 1.000 sec: 0.643847 ( -0.1242 0.125509 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.44132e-08 ( -9.9483e-09 1.06884e-08 ) ergs/cm2
Band function
Time interval is from -0.308 sec. to 0.692 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.336340 ( -1.37290 1.54941 )
beta : -9.30222 ( -0.697777 7.67647 )
Epeak [keV] : 61.1597 ( -15.8476 9938.84 )
Norm@50keV : 2.477402E-02 ( -1.978247E-02 4.688177E-02) )
------------------------------------------------------------
Chi-Squared = 54.01529 using 59 PHA bins.
Reduced chi-squared = 0.9820961 for 55 degrees of freedom
Null hypothesis probability = 0.512
Photon flux (15-150 keV) in 1.000 sec: 0.643853 ( -0.125888 0.125517 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.44115e-08 ( -9.9672e-09 1.06483e-08 ) ergs/cm2
Plot creation:
Thu Dec 13 21:22:25 EST 2007