batgrbproduct Analysis for Trigger=251634
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 16:16:21 EST 2008
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger251634/SDC
======================================================================
Trigger: 00251634 Segment: 000
BAT Trigger Time: 188019609.856 [s; MET]
Trigger Stop: 188019610.112 [s; MET]
UTC: 2006-12-17T03:40:08.217280 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 160.441664347489 Dec: -21.1182033163857 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 8.27
Image Trigger?: NO
Rate S/N Ratio: 21.6333076527839 [ if not an image trigger ]
Image S/N Ratio: 8.27
Flight Position: [ source = BAT ]
RA: 160.441664347489 Dec: -21.1182033163857 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 160.400200700238 Dec: -21.149866630009 [deg; J2000]
{ 10h 41m 36.0s , -21d 08' 59.5" }
+/- 2.27838264755342 [arcmin] (estimated 90% radius based on SNR)
+/- 1.07103028528492 [arcmin] (formal 1-sigma fit error)
SNR: 9.38043860269951
RA = 10h 41m 36.0s (160.400201 deg.)
Dec = -21d 8' 60" (-21.149867 deg.)
Angular difference between Flight and Ground position is 2.998982 arcmin
Partial Coding Fraction: 0.8515625 [ including projection effects ]
Duration
T90: 0.224000006914139 +/- 0.0456070257864576
Measured from: 0.0480000078678131
to: 0.272000014781952 [s; relative to TRIGTIME]
T50: 0.104000002145767 +/- 0.0432665955340684
Measured from: 0.111999988555908
to: 0.215999990701675 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: -0.342000007629395
to: 0.657999992370605 [s; relative to TRIGTIME]
Total Fluence
Measured from: 0.0279999971389771
to: 0.283999979496002 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.006664 0.016745 0.021359 0.011407
0.002738 0.003021 0.003041 0.002406 [error]
Peak 0.006408 0.017172 0.021487 0.011426
0.002767 0.003037 0.003063 0.002413 [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 2.36e-09 6.74e-09 1.56e-08 9.70e-08 4.20e-08 9.65e-08 erg/cm2
Error 8.84e-10 1.48e-09 2.63e-09 4.10e-08 7.22e-09 0.00e+00 erg/cm2
Peak flux Power-law 2.90e-01 4.48e-01 5.22e-01 1.17e+00 1.60e+00 2.43e+00 ph/cm2/s
Error 1.10e-01 1.02e-01 8.54e-02 4.48e-01 2.64e-01 4.60e-01 ph/cm2/s
Fluence Cutoff-PL 2.37e-09 6.76e-09 1.56e-08 9.61e-08 4.20e-08 7.92e-08 erg/cm2
Error 8.84e-10 1.48e-09 2.63e-09 4.24e-08 7.22e-09 0.00e+00 erg/cm2
Peak flux Cutoff-PL 2.89e-01 4.48e-01 5.22e-01 1.16e+00 1.60e+00 2.42e+00 ph/cm2/s
Error 1.10e-01 1.02e-01 8.55e-02 4.46e-01 2.64e-01 4.58e-01 ph/cm2/s
Fluence Band 2.37e-09 6.75e-09 1.55e-08 9.56e-08 4.20e-08 1.17e-07 erg/cm2
Error 7.34e-10 1.49e-09 2.88e-09 5.58e-08 7.21e-09 0.00e+00 erg/cm2
Peak flux Band 2.89e-01 4.48e-01 5.22e-01 1.16e+00 1.60e+00 2.18e+00 ph/cm2/s
Error 1.10e-01 1.02e-01 8.55e-02 4.58e-01 2.64e-01 5.37e-01 ph/cm2/s
=== Time-averaged spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 0.795 0.306 - - 1.40e-02 2.38e-03 54.900 57
CPL 0.788 0.309 9997.2 5000.0 1.41e-02 2.39e-03 54.908 56
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 0.781 0.306 - - 1.39e-02 2.37e-03 52.819 57
CPL 0.774 0.308 9999.0 5000.0 1.40e-02 2.38e-03 52.827 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: 0.192000 sec.
T50 in the 50-300 keV band: 0.064000 sec.
=== Table of the duration information ==
Value tstart tstop
T100 0.256 0.028 0.284
T90 0.224 0.048 0.272
T50 0.104 0.112 0.216
Peak 1.000 -0.342 0.658
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
160.4002 -21.1499 0.0204 14.9 -93.7 0.0531 9.4 TRIG_00251634
------------------------------------------
Foreground time interval of the image:
0.028 0.284 (delta_t = 0.256 [sec])
Background time interval of the image:
-187.651 0.028 (delta_t = 187.679 [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 0.028 sec. to 0.284 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.795263 ( -0.318085 0.294775 )
Norm@50keV : 1.401786E-02 ( -2.411644E-03 2.348970E-03) )
------------------------------------------------------------
Chi-Squared = 54.89964 using 59 PHA bins.
Reduced chi-squared = 0.9631515 for 57 degrees of freedom
Null hypothesis probability = 0.554
Photon flux (15-150 keV) in 0.2560 sec: 1.61139 ( -0.26624 0.26732 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.20319e-08 ( -7.20947e-09 7.23072e-09 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.028 sec. to 0.284 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.787993 ( -0.320961 0.297042 )
Epeak [keV] : 9997.22 ( -9997.21 2.77930 )
Norm@50keV : 1.412017E-02 ( -2.418962E-03 2.358508E-03) )
------------------------------------------------------------
Chi-Squared = 54.90771 using 59 PHA bins.
Reduced chi-squared = 0.9804948 for 56 degrees of freedom
Null hypothesis probability = 0.516
Photon flux (15-150 keV) in 0.2560 sec: 1.61103 ( -0.26615 0.26725 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.2036e-08 ( -7.20102e-09 7.24506e-09 ) ergs/cm2
Band function
Time interval is from 0.028 sec. to 0.284 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.819371 ( -9.18063 5.81937 )
beta : -0.795273 ( -0.294742 0.318096 )
Epeak [keV] : 17.3621 ( -17.2621 9982.64 )
Norm@50keV : 1.957679E-02 ( -7.830837E-03 321186. )
------------------------------------------------------------
Chi-Squared = 54.89964 using 59 PHA bins.
Reduced chi-squared = 0.9981752 for 55 degrees of freedom
Null hypothesis probability = 0.478
Photon flux (15-150 keV) in 0.2560 sec: 1.61103 ( -0.26614 0.26697 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.19707e-08 ( -7.15853e-09 7.26707e-09 ) ergs/cm2
Peak spectrum fit using the pre-slew DRM
Power-law model
Time interval is from 0.028 sec. to 0.288 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.781372 ( -0.317492 0.293991 )
Norm@50keV : 1.393893E-02 ( -2.400550E-03 2.334972E-03) )
------------------------------------------------------------
Chi-Squared = 52.81940 using 59 PHA bins.
Reduced chi-squared = 0.9266561 for 57 degrees of freedom
Null hypothesis probability = 0.633
Photon flux (15-150 keV) in 0.2600 sec: 1.60321 ( -0.2638 0.26495 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.26876e-08 ( -7.26362e-09 7.30262e-09 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.028 sec. to 0.288 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.774030 ( -0.320447 0.296217 )
Epeak [keV] : 9999.00 ( -9998.99 1.00195 )
Norm@50keV : 1.404191E-02 ( -2.407979E-03 2.344221E-03) )
------------------------------------------------------------
Chi-Squared = 52.82737 using 59 PHA bins.
Reduced chi-squared = 0.9433458 for 56 degrees of freedom
Null hypothesis probability = 0.596
Photon flux (15-150 keV) in 0.2600 sec: 1.60289 ( -0.26375 0.26486 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.27136e-08 ( -7.27688e-09 7.30496e-09 ) ergs/cm2
Band function
Time interval is from 0.028 sec. to 0.288 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.838340 ( -9.16166 5.83834 )
beta : -0.781447 ( -0.293883 0.317568 )
Epeak [keV] : 14.5913 ( -14.4913 9985.41 )
Norm@50keV : 2.060910E-02 ( -8.852128E-03 374918. )
------------------------------------------------------------
Chi-Squared = 52.81940 using 59 PHA bins.
Reduced chi-squared = 0.9603528 for 55 degrees of freedom
Null hypothesis probability = 0.558
Photon flux (15-150 keV) in 0.2600 sec: 1.60288 ( -0.26348 0.26471 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.26618e-08 ( -7.2475e-09 7.30886e-09 ) ergs/cm2
Plot creation:
Wed Jan 2 16:44:20 EST 2008