batgrbproduct Analysis for Trigger=254532
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 10:17:32 EST 2007
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger254532/GCN5_download_cron
======================================================================
Trigger: 00254532 Segment: 000
BAT Trigger Time: 189550001.088 [s; MET]
Trigger Stop: 189550001.6 [s; MET]
UTC: 2007-01-03T20:46:39.412140 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 352.557389445908 Dec: 26.8755363387016 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 9.86
Image Trigger?: NO
Rate S/N Ratio: 17.2336879396141 [ if not an image trigger ]
Image S/N Ratio: 9.86
Flight Position: [ source = BAT ]
RA: 352.557389445908 Dec: 26.8755363387016 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 352.582873031105 Dec: 26.8203705238828 [deg; J2000]
{ 23h 30m 19.9s , +26d 49' 13.3" }
+/- 2.75240066579743 [arcmin] (estimated 90% radius based on SNR)
+/- 2.00908995840863 [arcmin] (formal 1-sigma fit error)
SNR: 7.16075597335301
RA = 23h 30m 19.9s (352.582873 deg.)
Dec = 26d 49' 13" (26.820371 deg.)
Angular difference between Flight and Ground position is 3.580056 arcmin
Partial Coding Fraction: 0.84375 [ including projection effects ]
Duration
T90: 18.6119999885559 +/- 2.00141552168192
Measured from: 0.184000015258789
to: 18.7960000038147 [s; relative to TRIGTIME]
T50: 12.1520000100136 +/- 5.59586167746846
Measured from: 2.60400000214577
to: 14.7560000121593 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: -0.113999992609024
to: 0.886000007390976 [s; relative to TRIGTIME]
Total Fluence
Measured from: -0.104000002145767
to: 20.772000014782 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.240355 0.239622 0.122375 0.006356
0.023653 0.023788 0.020932 0.018529 [error]
Peak 0.042306 0.054593 0.019554 -0.001547
0.005594 0.005813 0.005018 0.004230 [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 7.20e-08 1.00e-07 1.04e-07 1.96e-07 3.38e-07 4.72e-07 erg/cm2
Error 1.15e-08 1.12e-08 2.03e-08 7.64e-08 4.63e-08 9.81e-08 erg/cm2
Peak flux Power-law 4.52e-01 3.70e-01 2.05e-01 1.67e-01 1.10e+00 1.19e+00 ph/cm2/s
Error 8.40e-02 4.80e-02 4.16e-02 6.42e-02 1.43e-01 1.58e-01 ph/cm2/s
Fluence Cutoff-PL 6.90e-08 1.07e-07 1.01e-07 7.85e-08 3.20e-07 3.56e-07 erg/cm2
Error 1.27e-08 1.18e-08 2.34e-08 1.29e-07 5.45e-08 1.39e-07 erg/cm2
Peak flux Cutoff-PL 3.78e-01 4.55e-01 1.88e-01 1.93e-02 1.04e+00 1.04e+00 ph/cm2/s
Error 1.03e-01 7.56e-02 5.60e-02 4.03e-02 1.48e-01 1.51e-01 ph/cm2/s
Fluence Band 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 Band 3.76e-01 4.58e-01 1.86e-01 4.34e-02 1.05e+00 1.06e+00 ph/cm2/s
Error 9.31e-02 5.88e-02 3.63e-02 5.71e-02 1.38e-01 1.54e-01 ph/cm2/s
=== Time-averaged spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.954 0.215 - - 1.76e-03 2.49e-04 47.493 57
CPL 1.409 0.924 45.2 5000.0 3.64e-03 7.10e-03 46.383 56
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.853 0.229 - - 7.82e-03 1.22e-03 67.344 57
CPL -0.110 1.602 43.6 10.7 1.09e-01 6.20e-01 60.982 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: 0.960000 sec.
T50 in the 50-300 keV band: 0.576000 sec.
=== Table of the duration information ==
Value tstart tstop
T100 20.876 -0.104 20.772
T90 18.612 0.184 18.796
T50 12.152 2.604 14.756
Peak 1.000 -0.114 0.886
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
352.5829 +26.8204 0.0267 20.2 -131.2 0.2134 7.2 TRIG_00254532
------------------------------------------
Foreground time interval of the image:
-0.104 8.613 (delta_t = 8.717 [sec])
Background time interval of the image:
-239.088 -233.188 (delta_t = 5.900 [sec])
-232.088 -0.104 (delta_t = 231.984 [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 -0.104 sec. to 20.772 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.95370 ( -0.209383 0.221275 )
Norm@50keV : 1.760693E-03 ( -2.517337E-04 2.452782E-04) )
------------------------------------------------------------
Chi-Squared = 47.49290 using 59 PHA bins.
Reduced chi-squared = 0.8332088 for 57 degrees of freedom
Null hypothesis probability = 0.811
Photon flux (15-150 keV) in 20.88 sec: 0.258638 ( -0.028818 0.028825 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.38377e-07 ( -4.57272e-08 4.68213e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.104 sec. to 20.772 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.40897 ( -1.01011 0.837002 )
Epeak [keV] : 45.1503 ( -45.1403 9954.85 )
Norm@50keV : 3.640572E-03 ( -3.640573E-03 1.056560E-02) )
------------------------------------------------------------
Chi-Squared = 46.38307 using 59 PHA bins.
Reduced chi-squared = 0.8282691 for 56 degrees of freedom
Null hypothesis probability = 0.817
Photon flux (15-150 keV) in 20.88 sec: 0.253569 ( -0.029915 0.02987 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.19978e-07 ( -5.24443e-08 5.65911e-08 ) ergs/cm2
Band function
Time interval is from -0.104 sec. to 20.772 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.951996 ( -9.04800 4.68590 )
beta : -2.21914 ( -7.78086 0.422658 )
Epeak [keV] : 35.7523 ( -35.6523 9964.25 )
Norm@50keV : 7.709539E-03 ( -0.222444 182.287 )
------------------------------------------------------------
Chi-Squared = 46.30482 using 59 PHA bins.
Reduced chi-squared = 0.8419058 for 55 degrees of freedom
Null hypothesis probability = 0.792
Photon flux (15-150 keV) in 20.88 sec: ( ) ph/cm2/s
Energy fluence (15-150 keV) : 0 ( 0 0 ) ergs/cm2
Peak spectrum fit using the pre-slew DRM
Power-law model
Time interval is from -0.104 sec. to 0.876 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.85332 ( -0.222435 0.235573 )
Norm@50keV : 7.822278E-03 ( -1.236949E-03 1.205002E-03) )
------------------------------------------------------------
Chi-Squared = 67.34352 using 59 PHA bins.
Reduced chi-squared = 1.181465 for 57 degrees of freedom
Null hypothesis probability = 0.164
Photon flux (15-150 keV) in 0.9800 sec: 1.10097 ( -0.142968 0.14299 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.04348e-08 ( -1.09053e-08 1.12603e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.104 sec. to 0.876 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.109665 ( -1.82061 1.38362 )
Epeak [keV] : 43.5953 ( -7.04085 14.3693 )
Norm@50keV : 0.109455 ( -0.109455 1.12982 )
------------------------------------------------------------
Chi-Squared = 60.98170 using 59 PHA bins.
Reduced chi-squared = 1.088959 for 56 degrees of freedom
Null hypothesis probability = 0.302
Photon flux (15-150 keV) in 0.9800 sec: 1.03907 ( -0.146971 0.14844 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.96605e-08 ( -1.03431e-08 1.22628e-08 ) ergs/cm2
Band function
Time interval is from -0.104 sec. to 0.876 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.956371 ( -1.90290 1.32009 )
beta : -2.56213 ( -6.48964 1.35435 )
Epeak [keV] : 48.5784 ( -9.56631 14.3012 )
Norm@50keV : 2.592892E-02 ( -0.112595 1.39911 )
------------------------------------------------------------
Chi-Squared = 62.36148 using 59 PHA bins.
Reduced chi-squared = 1.133845 for 55 degrees of freedom
Null hypothesis probability = 0.231
Photon flux (15-150 keV) in 0.9800 sec: 1.04648 ( -0.139342 0.13727 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.16742e-08 ( -1.13682e-08 1.16097e-08 ) ergs/cm2
Plot creation:
Thu Dec 13 10:32:42 EST 2007