batgrbproduct Analysis for Trigger=287042
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): Fri Dec 14 06:48:34 EST 2007
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger287042/GCN5_download_cron
======================================================================
Trigger: 00287042 Segment: 000
BAT Trigger Time: 208006048.512 [s; MET]
Trigger Stop: 208006049.536 [s; MET]
UTC: 2007-08-05T11:27:26.377140 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 272.651406826819 Dec: -26.1531288944347 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 7.08
Image Trigger?: NO
Rate S/N Ratio: 10.4403065089106 [ if not an image trigger ]
Image S/N Ratio: 7.08
Flight Position: [ source = BAT ]
RA: 272.651406826819 Dec: -26.1531288944347 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 272.675131228151 Dec: -26.1667740981668 [deg; J2000]
{ 18h 10m 42.0s , -26d 10' 00.4" }
+/- 1.9161484449658 [arcmin] (estimated 90% radius based on SNR)
+/- 0.868790743428849 [arcmin] (formal 1-sigma fit error)
SNR: 12.0129083629755
RA = 18h 10m 42.0s (272.675131 deg.)
Dec = -26d 10' 0" (-26.166774 deg.)
Angular difference between Flight and Ground position is 1.517462 arcmin
Partial Coding Fraction: 1.015625 [ including projection effects ]
Duration
T90: 8.04800000786781 +/- 1.33741990294174
Measured from: -3.4839999973774
to: 4.56400001049042 [s; relative to TRIGTIME]
T50: 3.68400001525879 +/- 1.41136528927783
Measured from: -1.61599999666214
to: 2.06800001859665 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: -1.63199999928474
to: -0.631999999284744 [s; relative to TRIGTIME]
Total Fluence
Measured from: -4.15599998831749
to: 5.09200000762939 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.296024 0.055557 -0.006363 0.021982
0.017901 0.015175 0.012918 0.011741 [error]
Peak 0.050062 0.009608 -0.000394 0.006284
0.006016 0.005051 0.004289 0.003920 [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 8.62e-08 1.91e-08 2.14e-09 2.66e-10 1.08e-07 1.08e-07 erg/cm2
Error 1.26e-08 7.04e-09 1.86e-09 4.63e-10 1.66e-08 1.66e-08 erg/cm2
Peak flux Power-law 5.25e-01 9.72e-02 8.71e-03 8.45e-04 6.32e-01 6.32e-01 ph/cm2/s
Error 1.07e-01 4.51e-02 1.06e-02 1.82e-03 1.32e-01 1.32e-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 0.00e+00 0.00e+00 0.00e+00 0.00e+00 0.00e+00 0.00e+00 ph/cm2/s
Error 0.00e+00 0.00e+00 0.00e+00 0.00e+00 0.00e+00 0.00e+00 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 4.76e-01 6.45e-01 0.00e+00 0.00e+00 0.00e+00 0.00e+00 ph/cm2/s
Error 1.33e-01 0.00e+00 0.00e+00 0.00e+00 0.00e+00 0.00e+00 ph/cm2/s
=== Time-averaged spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 5.004 0.697 - - 2.38e-04 1.92e-04 63.902 57
CPL 1.839 0.000 1.0 0.0 1.17e-01 0.00e+00 63.536 0
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 4.481 0.853 - - 6.66e-04 6.86e-04 56.243 57
CPL 1.758 0.000 1.9 0.0 1.09e-01 0.00e+00 55.587 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: 0.000000 sec.
T50 in the 50-300 keV band: 0.000000 sec.
=== Table of the duration information ==
Value tstart tstop
T100 9.248 -4.156 5.092
T90 8.048 -3.484 4.564
T50 3.684 -1.616 2.068
Peak 1.000 -1.632 -0.632
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
272.6751 -26.1668 0.0159 5.0 -13.1 0.3531 12.0 TRIG_00287042
------------------------------------------
Foreground time interval of the image:
-4.156 5.092 (delta_t = 9.248 [sec])
Background time interval of the image:
-239.512 -4.156 (delta_t = 235.356 [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 -4.156 sec. to 5.092 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 5.00394 ( -0.505728 0.887521 )
Norm@50keV : 2.377638E-04 ( -2.377638E-04 1.463447E-04) )
------------------------------------------------------------
Chi-Squared = 63.90173 using 59 PHA bins.
Reduced chi-squared = 1.121083 for 57 degrees of freedom
Null hypothesis probability = 0.247
Photon flux (15-150 keV) in 9.248 sec: 0.368139 ( -0.052672 0.052674 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.07673e-07 ( -1.64157e-08 1.66862e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -4.156 sec. to 5.092 sec.
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.83873 ( )
Epeak [keV] : 1.00108 ( )
Norm@50keV : 0.116858 ( )
------------------------------------------------------------
Chi-Squared = 63.53650 using 59 PHA bins.
but latest trial 1.01450 gives Chi-Squared = 92.9695
Reduced chi-squared = 1.134580 for 56 degrees of freedom
Null hypothesis probability = 0.228
Photon flux (15-150 keV) in 9.248 sec: ( ) ph/cm2/s
Energy fluence (15-150 keV) : 0 ( 0 0 ) ergs/cm2
Band function
Time interval is from -4.156 sec. to 5.092 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.85995 ( )
beta : -3.28633 ( )
Epeak [keV] : 4.55152 ( )
Norm@50keV : 4.917980E-03 ( )
------------------------------------------------------------
Chi-Squared = 110.4446 using 59 PHA bins.
Reduced chi-squared = 2.008084 for 55 degrees of freedom
Null hypothesis probability = 1.367E-05
Photon flux (15-150 keV) in 9.248 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 -1.632 sec. to -0.632 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 4.48144 ( -0.758107 0.947606 )
Norm@50keV : 6.658134E-04 ( -6.658134E-04 7.067053E-04) )
------------------------------------------------------------
Chi-Squared = 56.24327 using 59 PHA bins.
Reduced chi-squared = 0.9867240 for 57 degrees of freedom
Null hypothesis probability = 0.503
Photon flux (15-150 keV) in 1.000 sec: 0.632023 ( -0.131743 0.132178 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.12436e-08 ( -5.1166e-09 5.5201e-09 ) ergs/cm2
Cutoff power-law model
Time interval is from -1.632 sec. to -0.632 sec.
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.75770 ( )
Epeak [keV] : 1.93420 ( )
Norm@50keV : 0.108590 ( )
------------------------------------------------------------
Chi-Squared = 55.58651 using 59 PHA bins.
but latest trial 2.399361E-02 gives Chi-Squared = 44.3485
Reduced chi-squared = 0.9926162 for 56 degrees of freedom
Null hypothesis probability = 0.490
Photon flux (15-150 keV) in 1.000 sec: ( ) ph/cm2/s
Energy fluence (15-150 keV) : 0 ( 0 0 ) ergs/cm2
Band function
Time interval is from -1.632 sec. to -0.632 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.53293 ( -6.121635E-03 4.98047 )
beta : -4.25218 ( -0.945362 0.758401 )
Epeak [keV] : 13.9268 ( -13.6660 9986.23 )
Norm@50keV : 1.384943E-02 ( -5.773234E-02 9.613827E-02) )
------------------------------------------------------------
Chi-Squared = 77.91336 using 59 PHA bins.
Reduced chi-squared = 1.416607 for 55 degrees of freedom
Null hypothesis probability = 2.273E-02
Photon flux (15-150 keV) in 1.000 sec: ( ) ph/cm2/s
Energy fluence (15-150 keV) : 0 ( 0 0 ) ergs/cm2
Plot creation:
Fri Dec 14 07:03:00 EST 2007