batgrbproduct Analysis for Trigger=261880
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): Mon Dec 17 16:55:17 EST 2007
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger261880/SDC
======================================================================
Trigger: 00261880 Segment: 000
BAT Trigger Time: 194041680 [s; MET]
Trigger Stop: 194041744 [s; MET]
UTC: 2007-02-24T20:27:58.214180 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 178.989686201408 Dec: -13.3399298580834 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 7.5
Image Trigger?: YES
Rate S/N Ratio: 0 [ if not an image trigger ]
Image S/N Ratio: 7.5
Flight Position: [ source = BAT ]
RA: 178.989686201408 Dec: -13.3399298580834 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 178.997960953074 Dec: -13.372773147708 [deg; J2000]
{ 11h 55m 59.5s , -13d 22' 22.0" }
+/- 2.24039063240433 [arcmin] (estimated 90% radius based on SNR)
+/- 0.907722825972884 [arcmin] (formal 1-sigma fit error)
SNR: 9.60850637633444
RA = 11h 55m 59.5s (178.997961 deg.)
Dec = -13d 22' 22" (-13.372773 deg.)
Angular difference between Flight and Ground position is 2.028940 arcmin
Partial Coding Fraction: 1 [ including projection effects ]
Duration
T90: 56 +/- 20.2237484161567
Measured from: -14
to: 42 [s; relative to TRIGTIME]
T50: 22 +/- 8.94427190999916
Measured from: -7
to: 15 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: -14
to: -13 [s; relative to TRIGTIME]
Total Fluence
Measured from: -15
to: 46 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.388032 0.299240 0.088663 0.024477
0.036761 0.037163 0.032637 0.029027 [error]
Peak 0.018458 0.011605 0.005105 0.009670
0.004732 0.004728 0.004360 0.003682 [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 1.12e-07 1.19e-07 9.02e-08 1.11e-07 3.64e-07 4.32e-07 erg/cm2
Error 1.87e-08 1.81e-08 2.76e-08 6.42e-08 6.33e-08 1.02e-07 erg/cm2
Peak flux Power-law 1.22e-01 1.04e-01 6.05e-02 5.26e-02 3.09e-01 3.39e-01 ph/cm2/s
Error 9.72e-02 3.68e-02 4.99e-02 8.51e-02 1.10e-01 1.29e-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 1.22e-01 1.04e-01 6.04e-02 5.21e-02 3.09e-01 3.38e-01 ph/cm2/s
Error 9.72e-02 3.69e-02 4.99e-02 8.44e-02 1.10e-01 1.28e-01 ph/cm2/s
Fluence Band 3.71e-07 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 1.21e-01 1.04e-01 6.11e-02 5.44e-02 3.10e-01 3.49e-01 ph/cm2/s
Error 4.38e-02 3.68e-02 2.18e-02 6.44e-02 1.10e-01 0.00e+00 ph/cm2/s
=== Time-averaged spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 2.404 0.298 - - 6.11e-04 1.36e-04 66.789 57
CPL 1.534 0.000 19.4 0.0 2.15e-03 0.00e+00 65.990 56
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.778 0.908 - - 2.26e-03 1.08e-03 74.190 57
CPL 1.780 0.911 9992.4 5000.0 2.26e-03 1.09e-03 74.192 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 61.000 -15.000 46.000
T90 56.000 -14.000 42.000
T50 22.000 -7.000 15.000
Peak 1.000 -14.000 -13.000
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
178.9980 -13.3728 0.0200 12.3 -0.5 0.7844 9.6 TRIG_00261880
------------------------------------------
Foreground time interval of the image:
-15.000 46.000 (delta_t = 61.000 [sec])
Background time interval of the image:
-239.000 -15.000 (delta_t = 224.000 [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 -15.000 sec. to 46.000 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.40442 ( -0.282416 0.313473 )
Norm@50keV : 6.113859E-04 ( -1.375026E-04 1.353123E-04) )
------------------------------------------------------------
Chi-Squared = 66.78876 using 59 PHA bins.
Reduced chi-squared = 1.171733 for 57 degrees of freedom
Null hypothesis probability = 0.176
Photon flux (15-150 keV) in 61.00 sec: 0.113313 ( -0.0150182 0.015021 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.64058e-07 ( -6.18339e-08 6.46777e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -15.000 sec. to 46.000 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.53393 ( )
Epeak [keV] : 19.3534 ( )
Norm@50keV : 2.152108E-03 ( )
------------------------------------------------------------
Chi-Squared = 65.99038 using 59 PHA bins.
Reduced chi-squared = 1.178400 for 56 degrees of freedom
Null hypothesis probability = 0.170
Photon flux (15-150 keV) in 61.00 sec: ( ) ph/cm2/s
Energy fluence (15-150 keV) : 0 ( 0 0 ) ergs/cm2
Band function
Time interval is from -15.000 sec. to 46.000 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.55002 ( -8.44998 5.30186 )
beta : -3.34918 ( -6.65082 1.17959 )
Epeak [keV] : 19.1584 ( -19.0584 13.7378 )
Norm@50keV : 2.098043E-03 ( -2.098043E-03 1.40006 )
------------------------------------------------------------
Chi-Squared = 65.92509 using 59 PHA bins.
Reduced chi-squared = 1.198638 for 55 degrees of freedom
Null hypothesis probability = 0.149
Photon flux (15-150 keV) in 61.00 sec: 0.111240 ( -0.0153568 0.015159 ) 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 -14.000 sec. to -13.000 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.77775 ( -0.859688 0.955379 )
Norm@50keV : 2.257847E-03 ( -1.169112E-03 9.904341E-04) )
------------------------------------------------------------
Chi-Squared = 74.18958 using 59 PHA bins.
Reduced chi-squared = 1.301572 for 57 degrees of freedom
Null hypothesis probability = 6.267E-02
Photon flux (15-150 keV) in 1.000 sec: 0.308676 ( -0.109567 0.109564 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.08298e-08 ( -9.682e-09 1.06317e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -14.000 sec. to -13.000 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.78011 ( -0.864792 0.956366 )
Epeak [keV] : 9992.40 ( -9992.39 7.60352 )
Norm@50keV : 2.259027E-03 ( -1.172418E-03 9.982043E-04) )
------------------------------------------------------------
Chi-Squared = 74.19210 using 59 PHA bins.
Reduced chi-squared = 1.324859 for 56 degrees of freedom
Null hypothesis probability = 5.227E-02
Photon flux (15-150 keV) in 1.000 sec: 0.308506 ( -0.109536 0.109533 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.07671e-08 ( -9.6192e-09 1.06791e-08 ) ergs/cm2
Band function
Time interval is from -14.000 sec. to -13.000 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.35796 ( -8.00204 6.99796 )
beta : -1.67626 ( -8.23285 0.849320 )
Epeak [keV] : 3.41754 ( -0.375453 9999.52 )
Norm@50keV : 9.448225E-03 ( -8.467310E-04 6.083484E-02) )
------------------------------------------------------------
Chi-Squared = 74.23248 using 59 PHA bins.
Reduced chi-squared = 1.349681 for 55 degrees of freedom
Null hypothesis probability = 4.298E-02
Photon flux (15-150 keV) in 1.000 sec: 0.310262 ( -0.10993 0.109923 ) ph/cm2/s
Energy fluence (15-150 keV) : 2.05482e-08 ( -8.2975e-09 1.06673e-08 ) ergs/cm2
Plot creation:
Mon Dec 17 17:08:31 EST 2007