batgrbproduct Analysis for Trigger=277582
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 19:46:12 EST 2007
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger277582/SDC
======================================================================
Trigger: 00277582 Segment: 000
BAT Trigger Time: 199508946.368 [s; MET]
Trigger Stop: 199508946.752 [s; MET]
UTC: 2007-04-29T03:09:04.446800 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 328.024078768624 Dec: -38.8438832424751 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 8
Image Trigger?: NO
Rate S/N Ratio: 18.3575597506858 [ if not an image trigger ]
Image S/N Ratio: 8
Flight Position: [ source = BAT ]
RA: 328.024078768624 Dec: -38.8438832424751 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 328.007477514893 Dec: -38.8547482801677 [deg; J2000]
{ 21h 52m 01.8s , -38d 51' 17.1" }
+/- 1.88329250270272 [arcmin] (estimated 90% radius based on SNR)
+/- 0.836444523971986 [arcmin] (formal 1-sigma fit error)
SNR: 12.3134201335884
RA = 21h 52m 1.8s (328.007478 deg.)
Dec = -38d 51' 17" (-38.854748 deg.)
Angular difference between Flight and Ground position is 1.013288 arcmin
Partial Coding Fraction: 0.6640625 [ including projection effects ]
Duration
T90: 0.484000027179718 +/- 0.0393954444730255
Measured from: -0.196000009775162
to: 0.288000017404556 [s; relative to TRIGTIME]
T50: 0.356000006198883 +/- 0.0456070022619279
Measured from: -0.136000007390976
to: 0.219999998807907 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: -0.449999988079071
to: 0.550000011920929 [s; relative to TRIGTIME]
Total Fluence
Measured from: -0.208000004291534
to: 0.303999990224838 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.035693 0.040672 0.024730 0.001774
0.004727 0.005026 0.004345 0.003329 [error]
Peak 0.035239 0.041258 0.024730 0.001894
0.004764 0.005050 0.004345 0.003334 [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 1.06e-08 1.71e-08 2.08e-08 4.95e-08 6.26e-08 9.82e-08 erg/cm2
Error 2.13e-09 2.29e-09 4.14e-09 2.00e-08 9.84e-09 2.41e-08 erg/cm2
Peak flux Power-law 6.64e-01 5.90e-01 3.61e-01 3.35e-01 1.76e+00 1.95e+00 ph/cm2/s
Error 1.36e-01 8.01e-02 6.91e-02 1.25e-01 2.37e-01 2.66e-01 ph/cm2/s
Fluence Cutoff-PL 1.01e-08 1.85e-08 2.10e-08 1.99e-08 5.97e-08 6.65e-08 erg/cm2
Error 2.39e-09 3.27e-09 4.67e-09 3.31e-08 8.23e-09 3.38e-08 erg/cm2
Peak flux Cutoff-PL 6.16e-01 6.40e-01 3.72e-01 1.53e-01 1.73e+00 1.78e+00 ph/cm2/s
Error 1.55e-01 8.44e-02 7.83e-02 2.14e-01 2.42e-01 3.03e-01 ph/cm2/s
Fluence Band 9.82e-09 1.89e-08 2.01e-08 3.57e-08 6.05e-08 8.14e-08 erg/cm2
Error 2.32e-09 3.90e-09 4.88e-09 2.71e-08 1.06e-08 3.85e-08 erg/cm2
Peak flux Band 6.04e-01 6.58e-01 1.86e+00 0.00e+00 0.00e+00 0.00e+00 ph/cm2/s
Error 1.67e-01 3.05e-01 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 1.719 0.232 - - 1.32e-02 1.98e-03 41.459 57
CPL 1.135 1.059 66.7 4977.5 2.79e-02 5.73e-02 40.380 0
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.709 0.231 - - 1.32e-02 1.96e-03 42.568 57
CPL 1.052 0.875 65.1 4976.8 3.05e-02 6.93e-02 41.236 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 0.512 -0.208 0.304
T90 0.484 -0.196 0.288
T50 0.356 -0.136 0.220
Peak 1.000 -0.450 0.550
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
328.0075 -38.8547 0.0156 25.4 -58.7 0.1067 12.3 TRIG_00277582
------------------------------------------
Foreground time interval of the image:
-0.208 0.304 (delta_t = 0.512 [sec])
Background time interval of the image:
-161.563 -0.208 (delta_t = 161.355 [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 -0.208 sec. to 0.304 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.71863 ( -0.227498 0.237046 )
Norm@50keV : 1.323491E-02 ( -1.999108E-03 1.957376E-03) )
------------------------------------------------------------
Chi-Squared = 41.45937 using 59 PHA bins.
Reduced chi-squared = 0.7273574 for 57 degrees of freedom
Null hypothesis probability = 0.939
Photon flux (15-150 keV) in 0.5120 sec: 1.76934 ( -0.23804 0.23814 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.26309e-08 ( -9.73773e-09 9.93894e-09 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.208 sec. to 0.304 sec.
Parameters : value lower 90% higher 90%
Photon index: 1.13468 ( -1.21181 0.905847 )
Epeak [keV] : 66.7431 ( -21.7035 9933.26 )
Norm@50keV : 2.791687E-02 ( -1.000000E-02 0.104571 )
------------------------------------------------------------
Chi-Squared = 40.38018 using 59 PHA bins.
but latest trial 24.1767 gives Chi-Squared = 2.83054
but latest trial 1.099957E-02 gives Chi-Squared = 4.47447
Reduced chi-squared = 0.7210746 for 56 degrees of freedom
Null hypothesis probability = 0.943
Photon flux (15-150 keV) in 0.5120 sec: 1.74316 ( -0.24382 0.24227 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.97494e-08 ( -1.09333e-08 5.5209e-09 ) ergs/cm2
Band function
Time interval is from -0.208 sec. to 0.304 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.584802 ( -9.41520 3.83018 )
beta : -2.01151 ( -7.98849 0.445787 )
Epeak [keV] : 46.3016 ( -46.2016 9953.70 )
Norm@50keV : 6.544822E-02 ( -6.544822E-02 604.159 )
------------------------------------------------------------
Chi-Squared = 39.94605 using 59 PHA bins.
Reduced chi-squared = 0.7262918 for 55 degrees of freedom
Null hypothesis probability = 0.937
Photon flux (15-150 keV) in 0.5120 sec: 1.74663 ( -0.24317 0.2391 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.05215e-08 ( -1.09637e-08 1.03296e-08 ) ergs/cm2
Peak spectrum fit using the pre-slew DRM
Power-law model
Time interval is from -0.208 sec. to 0.308 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.70916 ( -0.226626 0.235761 )
Norm@50keV : 1.318807E-02 ( -1.981141E-03 1.942073E-03) )
------------------------------------------------------------
Chi-Squared = 42.56760 using 59 PHA bins.
Reduced chi-squared = 0.7468001 for 57 degrees of freedom
Null hypothesis probability = 0.923
Photon flux (15-150 keV) in 0.5160 sec: 1.75717 ( -0.23708 0.23718 ) ph/cm2/s
Energy fluence (15-150 keV) : 6.29401e-08 ( -9.75911e-09 9.96757e-09 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.208 sec. to 0.308 sec.
Photon index: 1.05220 ( -1.24312 0.506256 )
Epeak [keV] : 65.1333 ( -18.6665 9934.87 )
Norm@50keV : 3.046854E-02 ( -1.888947E-02 0.119630 )
------------------------------------------------------------
Chi-Squared = 41.23571 using 59 PHA bins.
but latest trial 1.96619 gives Chi-Squared = 4.53313
but latest trial 31.5199 gives Chi-Squared = 3.40697
but latest trial 1.125364E-02 gives Chi-Squared = 3.94065
Reduced chi-squared = 0.7363520 for 56 degrees of freedom
Null hypothesis probability = 0.930
Photon flux (15-150 keV) in 0.5160 sec: 1.72773 ( -0.24309 0.24144 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.97636e-08 ( -1.0956e-08 1.10429e-08 ) ergs/cm2
Band function
Time interval is from -0.208 sec. to 0.308 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.390337 ( -9.60966 3.49616 )
beta : -2.04166 ( -7.95834 0.467305 )
Epeak [keV] : 45.1865 ( -45.0865 880.086 )
Norm@50keV : 8.437444E-02 ( -7.230973E-02 472.643 )
------------------------------------------------------------
Chi-Squared = 40.75874 using 59 PHA bins.
Reduced chi-squared = 0.7410681 for 55 degrees of freedom
Null hypothesis probability = 0.924
Photon flux (15-150 keV) in 0.5160 sec: ( ) ph/cm2/s
Energy fluence (15-150 keV) : 0 ( 0 0 ) ergs/cm2
Plot creation:
Thu Dec 13 20:03:39 EST 2007