batgrbproduct Analysis for Trigger=306830
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 Mar 20 10:00:02 EDT 2008
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger306830/GCN5_download_cron
======================================================================
Trigger: 00306830 Segment: 000
BAT Trigger Time: 227660400 [s; MET]
Trigger Stop: 227660464 [s; MET]
UTC: 2008-03-19T22:59:57.344600 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 252.019112400084 Dec: -45.2043778098463 [deg; J2000]
Catalogged Source?: YES
Point Source?: YES
GRB Indicated?: NO [ by BAT flight software ]
Image S/N Ratio: 21.64
Image Trigger?: YES
Rate S/N Ratio: 0 [ if not an image trigger ]
Image S/N Ratio: 21.64
Flight Position: [ source = BAT ]
RA: 252.019112400084 Dec: -45.2043778098463 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 252.067836251136 Dec: -45.1737828478829 [deg; J2000]
{ 16h 48m 16.3s , -45d 10' 25.6" }
+/- nan [arcmin] (estimated 90% radius based on SNR)
+/- 2.32664199802175 [arcmin] (formal 1-sigma fit error)
SNR: -3.53056419778156
RA = 16h 48m 16.3s (252.067836 deg.)
Dec = -45d 10' 26" (-45.173783 deg.)
Angular difference between Flight and Ground position is 2.759494 arcmin
Partial Coding Fraction: 1 [ including projection effects ]
Duration
T90: 75.9519999623299 +/- 16.2577892835163
Measured from: 74.7120000123978
to: 150.663999974728 [s; relative to TRIGTIME]
T50: 51.1519999802113 +/- 25.8858046112936
Measured from: 94.0879999995232
to: 145.239999979734 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 75.0519999861717
to: 76.0519999861717 [s; relative to TRIGTIME]
Total Fluence
Measured from: 63.5439999997616
to: 159.511999994516 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 1.762607 1.144125 0.230248 0.004183
0.054477 0.047840 0.040382 0.035981 [error]
Peak 0.026932 0.022636 0.013315 0.002136
0.005641 0.004981 0.004084 0.003583 [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 5.58e-07 4.48e-07 2.43e-07 1.93e-07 1.34e-06 1.44e-06 erg/cm2
Error 4.49e-08 2.70e-08 3.13e-08 4.73e-08 7.83e-08 9.60e-08 erg/cm2
Peak flux Power-law 2.78e-01 1.85e-01 7.97e-02 4.73e-02 5.66e-01 5.90e-01 ph/cm2/s
Error 8.36e-02 4.02e-02 3.31e-02 3.81e-02 1.20e-01 1.26e-01 ph/cm2/s
Fluence Cutoff-PL 5.58e-07 4.49e-07 2.43e-07 1.91e-07 1.34e-06 1.44e-06 erg/cm2
Error 4.49e-08 2.70e-08 3.13e-08 4.69e-08 7.83e-08 9.58e-08 erg/cm2
Peak flux Cutoff-PL 2.78e-01 1.85e-01 7.97e-02 4.70e-02 5.66e-01 5.90e-01 ph/cm2/s
Error 8.36e-02 4.03e-02 3.31e-02 3.78e-02 1.20e-01 1.26e-01 ph/cm2/s
Fluence Band 5.11e-07 4.81e-07 1.80e-07 7.25e-08 1.22e-06 1.48e-06 erg/cm2
Error 4.92e-08 3.44e-08 4.37e-08 5.92e-08 1.01e-07 0.00e+00 erg/cm2
Peak flux Band 2.76e-01 1.85e-01 8.09e-02 4.88e-02 5.66e-01 5.92e-01 ph/cm2/s
Error 6.60e-02 3.93e-02 1.63e-02 2.01e-02 1.20e-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 2.883 0.136 - - 1.22e-03 1.13e-04 54.705 57
CPL 1.666 0.574 9.2 9.4 7.37e-03 1.07e-02 44.278 0
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 2.212 0.468 - - 3.40e-03 1.06e-03 50.008 57
CPL 1.994 0.695 1.3 0.0 4.41e-03 1.49e-02 50.190 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 95.968 63.544 159.512
T90 75.952 74.712 150.664
T50 51.152 94.088 145.240
Peak 1.000 75.052 76.052
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
252.0678 -45.1738 0.0545 0.0 -102.4 -0.2720 -3.5 TRIG_00306830
------------------------------------------
Foreground time interval of the image:
63.544 117.501 (delta_t = 53.957 [sec])
Background time interval of the image:
-119.000 -36.580 (delta_t = 82.420 [sec])
-35.000 63.544 (delta_t = 98.544 [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 63.544 sec. to 159.512 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.88321 ( -0.133959 0.138004 )
Norm@50keV : 1.220028E-03 ( -1.127125E-04 1.133352E-04) )
------------------------------------------------------------
Chi-Squared = 54.70534 using 59 PHA bins.
Reduced chi-squared = 0.9597428 for 57 degrees of freedom
Null hypothesis probability = 0.562
Photon flux (15-150 keV) in 95.97 sec: 0.308605 ( -0.018507 0.018603 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.33644e-06 ( -7.80812e-08 7.84651e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 63.544 sec. to 159.512 sec.
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.66570 ( -0.824595 0.322813 )
Epeak [keV] : 9.24730 ( -8.89400 9.94123 )
Norm@50keV : 7.370831E-03 ( -3.325188E-03 1.799778E-02) )
------------------------------------------------------------
Chi-Squared = 44.27828 using 59 PHA bins.
but latest trial -0.344494 gives Chi-Squared = 0.541656
Reduced chi-squared = 0.7906836 for 56 degrees of freedom
Null hypothesis probability = 0.871
Photon flux (15-150 keV) in 95.97 sec: 0.308446 ( -0.018497 0.018592 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.33629e-06 ( -7.8014e-08 7.85035e-08 ) ergs/cm2
Band function
Time interval is from 63.544 sec. to 159.512 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.46263 ( -0.729237 0.729237 )
beta : -8.70750 ( -0.418244 13.2377 )
Epeak [keV] : 14.9776 ( -7.17809 6.52489 )
Norm@50keV : 8.101869E-03 ( -3.113322E-03 474.467 )
------------------------------------------------------------
Chi-Squared = 48.42276 using 59 PHA bins.
Reduced chi-squared = 0.8804138 for 55 degrees of freedom
Null hypothesis probability = 0.722
Photon flux (15-150 keV) in 95.97 sec: 0.291432 ( -0.020624 0.020046 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.21772e-06 ( -1.01143e-07 1.00394e-07 ) ergs/cm2
Peak spectrum fit using the pre-slew DRM
Power-law model
Time interval is from 75.048 sec. to 76.056 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 2.21159 ( -0.432034 0.503033 )
Norm@50keV : 3.400011E-03 ( -1.091049E-03 1.024578E-03) )
------------------------------------------------------------
Chi-Squared = 50.00782 using 59 PHA bins.
Reduced chi-squared = 0.8773301 for 57 degrees of freedom
Null hypothesis probability = 0.733
Photon flux (15-150 keV) in 1.008 sec: 0.566338 ( -0.120065 0.120105 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.2279e-08 ( -8.36307e-09 8.77797e-09 ) ergs/cm2
Cutoff power-law model
Time interval is from 75.048 sec. to 76.056 sec.
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.99434 ( -1.21785 0.171775 )
Epeak [keV] : 1.27259 ( )
Norm@50keV : 4.412297E-03 ( -3.059055E-03 2.670896E-02) )
------------------------------------------------------------
Chi-Squared = 50.18989 using 59 PHA bins.
but latest trial 0.776495 gives Chi-Squared = 51.9638
Reduced chi-squared = 0.8962480 for 56 degrees of freedom
Null hypothesis probability = 0.693
Photon flux (15-150 keV) in 1.008 sec: 0.566124 ( -0.120022 0.120063 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.22821e-08 ( -8.36116e-09 8.77232e-09 ) ergs/cm2
Band function
Time interval is from 75.048 sec. to 76.056 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.82119 ( -3.490448E-04 14.9997 )
beta : -2.14388 ( -0.502786 0.432189 )
Epeak [keV] : 4.11741 ( -4.01741 9995.88 )
Norm@50keV : 8.999829E-03 ( -0.148571 0.139281 )
------------------------------------------------------------
Chi-Squared = 50.06993 using 59 PHA bins.
Reduced chi-squared = 0.9103624 for 55 degrees of freedom
Null hypothesis probability = 0.663
Photon flux (15-150 keV) in 1.008 sec: 0.566455 ( -0.119945 0.119906 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.23737e-08 ( -6.92647e-09 1.59139e-07 ) ergs/cm2
Plot creation:
Thu Mar 20 10:18:12 EDT 2008