batgrbproduct Analysis for Trigger=275988
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 17:43:20 EST 2007
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger275988/GCN5_download_cron
======================================================================
Trigger: 00275988 Segment: 000
BAT Trigger Time: 198555670.336 [s; MET]
Trigger Stop: 198555671.36 [s; MET]
UTC: 2007-04-18T02:21:08.438700 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 299.60489452301 Dec: 35.1895648617772 [deg; J2000]
Catalogged Source?: YES
Point Source?: YES
GRB Indicated?: NO [ by BAT flight software ]
Image S/N Ratio: 10.18
Image Trigger?: NO
Rate S/N Ratio: 14.8660687473185 [ if not an image trigger ]
Image S/N Ratio: 10.18
Flight Position: [ source = BAT ]
RA: 299.60489452301 Dec: 35.1895648617772 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 299.53567389409 Dec: 35.1763956796136 [deg; J2000]
{ 19h 58m 08.6s , +35d 10' 35.0" }
+/- 2.68288032748972 [arcmin] (estimated 90% radius based on SNR)
+/- 1.42143069503114 [arcmin] (formal 1-sigma fit error)
SNR: 7.42729728217216
RA = 19h 58m 8.6s (299.535674 deg.)
Dec = 35d 10' 35" (35.176396 deg.)
Angular difference between Flight and Ground position is 3.485258 arcmin
Partial Coding Fraction: 1 [ including projection effects ]
Duration
T90: 11 +/- 2.82842712474619
Measured from: -7.33599999547005
to: 3.66400000452995 [s; relative to TRIGTIME]
T50: 6 +/- 1
Measured from: -4.33599999547005
to: 1.66400000452995 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: -0.335999995470047
to: 0.664000004529953 [s; relative to TRIGTIME]
Total Fluence
Measured from: -8.33599999547005
to: 4.66400000452995 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.249903 0.306443 0.173088 0.030265
0.017414 0.017604 0.015616 0.014331 [error]
Peak 0.036061 0.050570 0.022240 0.004863
0.005093 0.005177 0.004529 0.004064 [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 7.59e-08 1.21e-07 1.45e-07 3.38e-07 4.38e-07 6.76e-07 erg/cm2
Error 8.69e-09 8.52e-09 1.55e-08 7.58e-08 3.58e-08 8.92e-08 erg/cm2
Peak flux Power-law 3.49e-01 3.00e-01 1.77e-01 1.55e-01 8.93e-01 9.81e-01 ph/cm2/s
Error 7.00e-02 4.12e-02 3.64e-02 6.15e-02 1.22e-01 1.38e-01 ph/cm2/s
Fluence Cutoff-PL 7.28e-08 1.26e-07 1.44e-07 1.80e-07 4.22e-07 5.29e-07 erg/cm2
Error 9.95e-09 1.13e-08 1.64e-08 1.49e-07 4.23e-08 1.63e-07 erg/cm2
Peak flux Cutoff-PL 3.22e-01 3.54e-01 1.58e-01 2.46e-02 8.56e-01 8.59e-01 ph/cm2/s
Error 7.71e-02 6.95e-02 6.11e-02 6.82e-02 1.28e-01 1.39e-01 ph/cm2/s
Fluence Band 7.18e-08 1.26e-07 1.40e-07 2.82e-07 4.27e-07 6.16e-07 erg/cm2
Error 1.04e-08 1.21e-08 1.31e-08 1.50e-07 4.15e-08 1.56e-07 erg/cm2
Peak flux Band 3.08e-01 3.70e-01 1.53e-01 8.02e-02 8.77e-01 9.33e-01 ph/cm2/s
Error 8.94e-02 6.34e-02 4.29e-02 7.74e-02 1.27e-01 1.98e-01 ph/cm2/s
=== Time-averaged spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.741 0.133 - - 3.65e-03 2.84e-04 57.372 57
CPL 1.360 0.527 76.2 4973.6 5.88e-03 4.58e-03 55.882 0
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.766 0.238 - - 6.56e-03 1.04e-03 78.627 57
CPL 0.384 1.823 45.1 51.0 4.57e-02 7.45e-01 75.288 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: 0.064000 sec.
T50 in the 50-300 keV band: 0.064000 sec.
=== Table of the duration information ==
Value tstart tstop
T100 13.000 -8.336 4.664
T90 11.000 -7.336 3.664
T50 6.000 -4.336 1.664
Peak 1.000 -0.336 0.664
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
299.5357 +35.1764 0.0259 16.2 -13.9 0.6130 7.4 TRIG_00275988
------------------------------------------
Foreground time interval of the image:
-8.336 4.664 (delta_t = 13.000 [sec])
Background time interval of the image:
-10.336 -8.336 (delta_t = 2.000 [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 -8.336 sec. to 4.664 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.74065 ( -0.131510 0.133645 )
Norm@50keV : 3.651281E-03 ( -2.855165E-04 2.823577E-04) )
------------------------------------------------------------
Chi-Squared = 57.37179 using 59 PHA bins.
Reduced chi-squared = 1.006523 for 57 degrees of freedom
Null hypothesis probability = 0.461
Photon flux (15-150 keV) in 13.00 sec: 0.492023 ( -0.035042 0.035082 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.38361e-07 ( -3.56629e-08 3.58488e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -8.336 sec. to 4.664 sec.
Parameters : value lower 90% higher 90%
Photon index: 1.36007 ( -0.585192 0.469075 )
Epeak [keV] : 76.2083 ( -23.4729 9923.79 )
Norm@50keV : 5.879923E-03 ( -2.906735E-03 6.255908E-03) )
------------------------------------------------------------
Chi-Squared = 55.88155 using 59 PHA bins.
but latest trial 44.3742 gives Chi-Squared = 7.97332
but latest trial 3.147538E-03 gives Chi-Squared = 9.90433
Reduced chi-squared = 0.9978848 for 56 degrees of freedom
Null hypothesis probability = 0.479
Photon flux (15-150 keV) in 13.00 sec: 0.483074 ( -0.037342 0.036987 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.21873e-07 ( -4.27596e-08 4.18795e-08 ) ergs/cm2
Band function
Time interval is from -8.336 sec. to 4.664 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.823133 ( -9.17687 3.66604 )
beta : -1.89566 ( -8.10434 0.226367 )
Epeak [keV] : 44.2478 ( -44.1478 4308.34 )
Norm@50keV : 1.383073E-02 ( -1.383073E-02 269.786 )
------------------------------------------------------------
Chi-Squared = 55.11562 using 59 PHA bins.
Reduced chi-squared = 1.002102 for 55 degrees of freedom
Null hypothesis probability = 0.470
Photon flux (15-150 keV) in 13.00 sec: 0.482108 ( -0.03692 0.036937 ) ph/cm2/s
Energy fluence (15-150 keV) : 4.26534e-07 ( -4.40336e-08 3.90546e-08 ) ergs/cm2
Peak spectrum fit using the pre-slew DRM
Power-law model
Time interval is from -0.336 sec. to 0.664 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.76602 ( -0.233671 0.241934 )
Norm@50keV : 6.564269E-03 ( -1.053670E-03 1.033854E-03) )
------------------------------------------------------------
Chi-Squared = 78.62726 using 59 PHA bins.
Reduced chi-squared = 1.379426 for 57 degrees of freedom
Null hypothesis probability = 3.038E-02
Photon flux (15-150 keV) in 1.000 sec: 0.892918 ( -0.122444 0.122472 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.04736e-08 ( -9.8051e-09 1.01637e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.336 sec. to 0.664 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.383522 ( -2.34636 1.29936 )
Epeak [keV] : 45.0633 ( -9.97102 91.9626 )
Norm@50keV : 4.568966E-02 ( -3.811268E-02 1.45150 )
------------------------------------------------------------
Chi-Squared = 75.28787 using 59 PHA bins.
Reduced chi-squared = 1.344426 for 56 degrees of freedom
Null hypothesis probability = 4.375E-02
Photon flux (15-150 keV) in 1.000 sec: 0.855645 ( -0.128389 0.128201 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.1067e-08 ( -1.18186e-08 1.33816e-08 ) ergs/cm2
Band function
Time interval is from -0.336 sec. to 0.664 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : 0.144607 ( -3.40861 1.49540 )
beta : -2.28195 ( -0.734584 0.431357 )
Epeak [keV] : 37.7434 ( -7.16526 8.43352 )
Norm@50keV : 0.115555 ( -130.861 36.6265 )
------------------------------------------------------------
Chi-Squared = 72.27695 using 59 PHA bins.
Reduced chi-squared = 1.314126 for 55 degrees of freedom
Null hypothesis probability = 5.903E-02
Photon flux (15-150 keV) in 1.000 sec: 0.876791 ( -0.122493 0.131209 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.49286e-08 ( -1.02805e-08 1.00086e-08 ) ergs/cm2
Plot creation:
Thu Dec 13 17:47:42 EST 2007