batgrbproduct Analysis for Trigger=250908
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): Wed Jan 2 15:55:36 EST 2008
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger250908/GCN5_download_cron
======================================================================
Trigger: 00250908 Segment: 000
BAT Trigger Time: 187791415.036 [s; MET]
Trigger Stop: 187791415.364 [s; MET]
UTC: 2006-12-14T12:16:53.402800 [includes UTCF correction]
Where From?: (*SHORT BURST*) Expanded to TRIGTIME - 4 ms to TRIGTIME + 320 ms
BAT
RA: 7.7766114981453 Dec: -29.6401990420507 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 6.03
Image Trigger?: NO
Rate S/N Ratio: 10.4880884817015 [ if not an image trigger ]
Image S/N Ratio: 6.03
Flight Position: [ source = BAT ]
RA: 7.7766114981453 Dec: -29.6401990420507 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 7.78711386423975 Dec: -29.6480067855972 [deg; J2000]
{ 00h 31m 08.9s , -29d 38' 52.8" }
+/- 90.4253083985773 [arcmin] (estimated 90% radius based on SNR)
+/- 240.242783209637 [arcmin] (formal 1-sigma fit error)
SNR: 0.0487998381892424
RA = 0h 31m 8.9s (7.787114 deg.)
Dec = -29d 38' 53" (-29.648007 deg.)
Angular difference between Flight and Ground position is 0.720692 arcmin
Partial Coding Fraction: 0.6015625 [ including projection effects ]
Duration
T90: 0.328000009059906 +/-
Measured from: 0
to: 0.328000009059906 [s; relative to TRIGTIME]
T50: 0.328000009059906 +/-
Measured from: 0
to: 0.328000009059906 [s; relative to TRIGTIME]
WARNING: battblocks failed. Used TDRSS fore/background intervals
Fluence
Peak Flux (peak 0.328000009059906 second)
Measured from: 0
to: 0.328000009059906 [s; relative to TRIGTIME]
Total Fluence
Measured from: 0
to: 0.328000009059906 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total -0.000415 -0.000291 -0.001624 0.001272
0.003379 0.003547 0.003183 0.002667 [error]
Peak -0.000415 -0.000291 -0.001624 0.001272
0.003379 0.003547 0.003183 0.002667 [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 1.72e-12 2.22e-11 2.46e-10 2.07e-08 1.10e-09 0.00e+00 erg/cm2
Error 5.87e-10 6.43e-10 1.19e-09 5.84e-08 3.52e-09 0.00e+00 erg/cm2
Peak flux Power-law 1.95e-04 1.07e-03 5.90e-03 1.52e-01 1.96e-02 0.00e+00 ph/cm2/s
Error 5.99e-02 3.53e-02 3.07e-02 4.27e-01 1.05e-01 0.00e+00 ph/cm2/s
Fluence Cutoff-PL 9.72e-13 1.97e-11 2.45e-10 2.49e-08 1.16e-09 0.00e+00 erg/cm2
Error 5.85e-10 6.45e-10 1.19e-09 6.58e-08 3.52e-09 0.00e+00 erg/cm2
Peak flux Cutoff-PL 1.45e-04 9.50e-04 5.89e-03 1.81e-01 2.04e-02 0.00e+00 ph/cm2/s
Error 5.96e-02 3.51e-02 3.07e-02 4.76e-01 1.04e-01 0.00e+00 ph/cm2/s
Fluence Band 2.61e-13 1.09e-12 8.18e-11 1.54e-07 1.00e-09 0.00e+00 erg/cm2
Error 5.69e-10 1.28e-09 2.38e-07 3.43e-09 0.00e+00 0.00e+00 erg/cm2
Peak flux Band 1.92e-04 9.32e-05 2.57e-03 8.76e-01 1.49e-02 0.00e+00 ph/cm2/s
Error 5.94e-02 3.29e-02 3.24e-02 2.48e+00 9.27e-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 1.500 6.500 - - 0.00e+00 8.65e-04 52.247 57
CPL 1.000 6.500 50.0 5000.0 0.00e+00 5.00e+23 52.247 56
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.500 6.500 - - 0.00e+00 8.65e-04 52.247 57
CPL 1.000 6.500 50.0 5000.0 0.00e+00 5.00e+23 52.247 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 0.328 0.000 0.328
T90 0.328 0.000 0.328
T50 0.328 0.000 0.328
Peak 0.328 0.000 0.328
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
7.7871 -29.6480 3.9171 36.2 -25.1 0.0003 0.0 TRIG_00250908
------------------------------------------
Foreground time interval of the image:
-0.004 0.324 (delta_t = 0.328 [sec])
Background time interval of the image:
-60.040 -7.040 (delta_t = 53.000 [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 -0.004 sec. to 0.324 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.50000 ( -4.50000 8.50000 )
Norm@50keV : 0.00000 ( 0.00000 1.730650E-03) )
------------------------------------------------------------
Chi-Squared = 52.24662 using 59 PHA bins.
Reduced chi-squared = 0.9166074 for 57 degrees of freedom
Null hypothesis probability = 0.654
Photon flux (15-150 keV) in 0.3280 sec: 1.956547E-02 ( -0.0195655 0.190091 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.10312e-09 ( -1.10312e-09 5.94507e-09 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.004 sec. to 0.324 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.00000 ( -4.00000 9.00000 )
Epeak [keV] : 50.0000 ( -49.9900 9950.00 )
Norm@50keV : 0.00000 ( 0.00000 1.000000E+24) )
------------------------------------------------------------
Chi-Squared = 52.24662 using 59 PHA bins.
Reduced chi-squared = 0.9329754 for 56 degrees of freedom
Null hypothesis probability = 0.618
Photon flux (15-150 keV) in 0.3280 sec: 2.035987E-02 ( -0.0203599 0.188027 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.16196e-09 ( -1.16196e-09 5.87343e-09 ) ergs/cm2
Band function
Time interval is from -0.004 sec. to 0.324 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.983950 ( -9.01605 5.98395 )
beta : -2.50000 ( -7.50000 12.5000 )
Epeak [keV] : 80.0000 ( -79.9000 9920.00 )
Norm@50keV : 0.00000 ( -1.644992E-02 113.823 )
------------------------------------------------------------
Chi-Squared = 52.24662 using 59 PHA bins.
Reduced chi-squared = 0.9499386 for 55 degrees of freedom
Null hypothesis probability = 0.580
Photon flux (15-150 keV) in 0.3280 sec: 1.494947E-02 ( -0.0149495 0.170368 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.00126e-09 ( -1.00126e-09 5.8546e-09 ) ergs/cm2
Peak spectrum fit using the pre-slew DRM
Power-law model
Time interval is from -0.004 sec. to 0.324 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.50000 ( -4.50000 8.50000 )
Norm@50keV : 0.00000 ( 0.00000 1.730650E-03) )
------------------------------------------------------------
Chi-Squared = 52.24662 using 59 PHA bins.
Reduced chi-squared = 0.9166074 for 57 degrees of freedom
Null hypothesis probability = 0.654
Photon flux (15-150 keV) in 0.3280 sec: 1.956547E-02 ( -0.0195655 0.190091 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.10312e-09 ( -1.10312e-09 5.94507e-09 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.004 sec. to 0.324 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.00000 ( -4.00000 9.00000 )
Epeak [keV] : 50.0000 ( -49.9900 9950.00 )
Norm@50keV : 0.00000 ( 0.00000 1.000000E+24) )
------------------------------------------------------------
Chi-Squared = 52.24662 using 59 PHA bins.
Reduced chi-squared = 0.9329754 for 56 degrees of freedom
Null hypothesis probability = 0.618
Photon flux (15-150 keV) in 0.3280 sec: 2.035987E-02 ( -0.0203599 0.188027 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.16196e-09 ( -1.16196e-09 5.87343e-09 ) ergs/cm2
Band function
Time interval is from -0.004 sec. to 0.324 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.983950 ( -9.01605 5.98395 )
beta : -2.50000 ( -7.50000 12.5000 )
Epeak [keV] : 80.0000 ( -79.9000 9920.00 )
Norm@50keV : 0.00000 ( -1.644992E-02 113.823 )
------------------------------------------------------------
Chi-Squared = 52.24662 using 59 PHA bins.
Reduced chi-squared = 0.9499386 for 55 degrees of freedom
Null hypothesis probability = 0.580
Photon flux (15-150 keV) in 0.3280 sec: 1.494947E-02 ( -0.0149495 0.170368 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.00126e-09 ( -1.00126e-09 5.8546e-09 ) ergs/cm2
Plot creation:
Wed Jan 2 16:13:31 EST 2008