batgrbproduct Analysis for Trigger=277356
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 19:06:12 EST 2007
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger277356/GCN5_download_cron
======================================================================
Trigger: 00277356 Segment: 000
BAT Trigger Time: 199355470.848 [s; MET]
Trigger Stop: 199355471.872 [s; MET]
UTC: 2007-04-27T08:31:08.930660 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 28.8618505141047 Dec: -27.6329554026753 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 8.85
Image Trigger?: NO
Rate S/N Ratio: 11.7898261225516 [ if not an image trigger ]
Image S/N Ratio: 8.85
Flight Position: [ source = BAT ]
RA: 28.8618505141047 Dec: -27.6329554026753 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 28.8771809060568 Dec: -27.6053196861895 [deg; J2000]
{ 01h 55m 30.5s , -27d 36' 19.2" }
+/- 0.791137892540047 [arcmin] (estimated 90% radius based on SNR)
+/- 0.251548080816001 [arcmin] (formal 1-sigma fit error)
SNR: 42.5081691293519
RA = 1h 55m 30.5s (28.877181 deg.)
Dec = -27d 36' 19" (-27.605320 deg.)
Angular difference between Flight and Ground position is 1.847614 arcmin
Partial Coding Fraction: 1 [ including projection effects ]
Duration
T90: 11.0960000157356 +/- 0.981688346938688
Measured from: 0.636000007390976
to: 11.7320000231266 [s; relative to TRIGTIME]
T50: 5.70800000429153 +/- 0.567492717538229
Measured from: 3.14400002360344
to: 8.85200002789497 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 6.79199999570847
to: 7.79199999570847 [s; relative to TRIGTIME]
Total Fluence
Measured from: -0.179999977350235
to: 13.688000023365 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.553485 0.545388 0.253270 0.037739
0.018380 0.018631 0.016024 0.013452 [error]
Peak 0.058498 0.064928 0.028617 0.004790
0.005172 0.005326 0.004545 0.003692 [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 1.72e-07 2.22e-07 2.09e-07 3.50e-07 7.20e-07 9.56e-07 erg/cm2
Error 1.32e-08 1.01e-08 1.60e-08 5.61e-08 3.58e-08 6.99e-08 erg/cm2
Peak flux Power-law 5.87e-01 4.46e-01 2.27e-01 1.65e-01 1.34e+00 1.42e+00 ph/cm2/s
Error 8.52e-02 4.39e-02 3.75e-02 5.25e-02 1.32e-01 1.41e-01 ph/cm2/s
Fluence Cutoff-PL 1.63e-07 2.29e-07 2.08e-07 1.93e-07 6.94e-07 7.95e-07 erg/cm2
Error 1.57e-08 1.26e-08 1.73e-08 1.23e-07 4.46e-08 1.33e-07 erg/cm2
Peak flux Cutoff-PL 5.44e-01 4.86e-01 2.22e-01 6.10e-02 1.30e+00 1.31e+00 ph/cm2/s
Error 9.81e-02 6.24e-02 4.45e-02 9.03e-02 1.39e-01 1.58e-01 ph/cm2/s
Fluence Band 1.59e-07 2.30e-07 2.02e-07 2.98e-07 6.98e-07 8.91e-07 erg/cm2
Error 1.70e-08 1.38e-08 1.83e-08 1.20e-07 4.37e-08 1.38e-07 erg/cm2
Peak flux Band 5.38e-01 4.93e-01 2.14e-01 1.02e-01 1.30e+00 1.35e+00 ph/cm2/s
Error 1.01e-01 6.37e-02 4.52e-02 8.08e-02 1.38e-01 1.28e-01 ph/cm2/s
=== Time-averaged spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 2.082 0.096 - - 5.60e-03 3.01e-04 36.407 57
CPL 1.723 0.319 34.1 22.0 8.78e-03 4.36e-03 33.690 0
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.977 0.189 - - 9.00e-03 1.12e-03 60.380 57
CPL 1.209 0.943 42.8 5000.0 2.50e-02 4.86e-02 57.895 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: 7.808000 sec.
T50 in the 50-300 keV band: 5.056000 sec.
=== Table of the duration information ==
Value tstart tstop
T100 13.868 -0.180 13.688
T90 11.096 0.636 11.732
T50 5.708 3.144 8.852
Peak 1.000 6.792 7.792
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
28.8772 -27.6053 0.0046 14.8 -27.8 1.4202 42.5 TRIG_00277356
------------------------------------------
Foreground time interval of the image:
-0.180 13.688 (delta_t = 13.868 [sec])
Background time interval of the image:
-239.848 -0.180 (delta_t = 239.668 [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 -0.180 sec. to 13.688 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.08208 ( -9.484863E-02 9.642386E-02) )
Norm@50keV : 5.597704E-03 ( -3.026230E-04 2.988791E-04) )
------------------------------------------------------------
Chi-Squared = 36.40697 using 59 PHA bins.
Reduced chi-squared = 0.6387188 for 57 degrees of freedom
Null hypothesis probability = 0.985
Photon flux (15-150 keV) in 13.87 sec: 0.872956 ( -0.0426 0.042774 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.20136e-07 ( -3.56598e-08 3.59344e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.180 sec. to 13.688 sec.
Parameters : value lower 90% higher 90%
Photon index: 1.72281 ( -0.412881 0.224406 )
Epeak [keV] : 34.1334 ( -30.8382 13.1227 )
Norm@50keV : 8.780379E-03 ( -2.875064E-03 5.850310E-03) )
------------------------------------------------------------
Chi-Squared = 33.68956 using 59 PHA bins.
but latest trial 2.08829 gives Chi-Squared = 2.84288
but latest trial 2.93268 gives Chi-Squared = 25.5625
Reduced chi-squared = 0.6015993 for 56 degrees of freedom
Null hypothesis probability = 0.992
Photon flux (15-150 keV) in 13.87 sec: 0.851762 ( -0.0477 0.047671 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.93673e-07 ( -4.44561e-08 4.47169e-08 ) ergs/cm2
Band function
Time interval is from -0.180 sec. to 13.688 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.38838 ( -1.15882 2.18575 )
beta : -2.24643 ( -7.75356 0.197968 )
Epeak [keV] : 32.1193 ( -13.1690 12.6538 )
Norm@50keV : 1.474138E-02 ( -0.265570 666.112 )
------------------------------------------------------------
Chi-Squared = 32.84770 using 59 PHA bins.
Reduced chi-squared = 0.5972310 for 55 degrees of freedom
Null hypothesis probability = 0.992
Photon flux (15-150 keV) in 13.87 sec: 0.846639 ( -0.049387 0.049441 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.9833e-07 ( -4.35019e-08 4.39485e-08 ) ergs/cm2
Peak spectrum fit using the pre-slew DRM
Power-law model
Time interval is from 6.792 sec. to 7.792 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.97692 ( -0.184563 0.194137 )
Norm@50keV : 9.001745E-03 ( -1.130071E-03 1.103729E-03) )
------------------------------------------------------------
Chi-Squared = 60.38042 using 59 PHA bins.
Reduced chi-squared = 1.059306 for 57 degrees of freedom
Null hypothesis probability = 0.355
Photon flux (15-150 keV) in 1.000 sec: 1.33613 ( -0.13191 0.13196 ) ph/cm2/s
Energy fluence (15-150 keV) : 8.29099e-08 ( -9.7645e-09 1.00023e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 6.792 sec. to 7.792 sec.
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.20912 ( -1.06684 0.819013 )
Epeak [keV] : 42.7631 ( -42.7531 9957.24 )
Norm@50keV : 2.502280E-02 ( -1.643576E-02 8.072072E-02) )
------------------------------------------------------------
Chi-Squared = 57.89512 using 59 PHA bins.
but latest trial 2.02947 gives Chi-Squared = 2.74321
Reduced chi-squared = 1.033841 for 56 degrees of freedom
Null hypothesis probability = 0.405
Photon flux (15-150 keV) in 1.000 sec: 1.29715 ( -0.13884 0.13854 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.67882e-08 ( -1.12866e-08 1.18747e-08 ) ergs/cm2
Band function
Time interval is from 6.792 sec. to 7.792 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.22733 ( -8.77267 1.08006 )
beta : -9.10877 ( -7.56510 0.484267 )
Epeak [keV] : 42.8142 ( -16.8840 98.1051 )
Norm@50keV : 2.442351E-02 ( -4.023387E-02 3.79285 )
------------------------------------------------------------
Chi-Squared = 57.89627 using 59 PHA bins.
Reduced chi-squared = 1.052659 for 55 degrees of freedom
Null hypothesis probability = 0.369
Photon flux (15-150 keV) in 1.000 sec: 1.29912 ( -0.13871 0.1364 ) ph/cm2/s
Energy fluence (15-150 keV) : 7.80733e-08 ( -1.19443e-08 1.07823e-08 ) ergs/cm2
Plot creation:
Thu Dec 13 19:26:11 EST 2007