batgrbproduct Analysis for Trigger=279898
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 22:48:32 EST 2007
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger279898/GCN5_download_cron
======================================================================
Trigger: 00279898 Segment: 000
BAT Trigger Time: 201375895.232 [s; MET]
Trigger Stop: 201375899.328 [s; MET]
UTC: 2007-05-20T17:44:53.264200 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 121.951513642403 Dec: 57.6167755712018 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 7.32
Image Trigger?: NO
Rate S/N Ratio: 10 [ if not an image trigger ]
Image S/N Ratio: 7.32
Flight Position: [ source = BAT ]
RA: 121.951513642403 Dec: 57.6167755712018 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 121.88566913677 Dec: 57.6004058056566 [deg; J2000]
{ 08h 07m 32.6s , +57d 36' 01.5" }
+/- 2.04262166370348 [arcmin] (estimated 90% radius based on SNR)
+/- 0.898632972770487 [arcmin] (formal 1-sigma fit error)
SNR: 10.96459918445
RA = 8h 7m 32.6s (121.885669 deg.)
Dec = 57d 36' 1" (57.600406 deg.)
Angular difference between Flight and Ground position is 2.333180 arcmin
Partial Coding Fraction: 0.59375 [ including projection effects ]
Duration
T90: 96 +/- 35.7770876399966
Measured from: -15.2319999933243
to: 80.7680000066757 [s; relative to TRIGTIME]
T50: 48 +/- 16
Measured from: 0.76800000667572
to: 48.7680000066757 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 8.26800000667572
to: 9.26800000667572 [s; relative to TRIGTIME]
Total Fluence
Measured from: -15.2319999933243
to: 96.7680000066757 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.357281 0.463345 0.499648 0.150504
0.056212 0.057136 0.051076 0.043644 [error]
Peak 0.090570 0.164196 0.175071 0.066695
0.023580 0.024189 0.022008 0.018471 [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 1.00e-07 2.20e-07 3.81e-07 1.53e-06 1.04e-06 2.21e-06 erg/cm2
Error 2.38e-08 3.02e-08 4.99e-08 4.77e-07 1.27e-07 5.00e-07 erg/cm2
Peak flux Power-law 6.25e-02 7.87e-02 7.23e-02 1.16e-01 2.53e-01 3.30e-01 ph/cm2/s
Error 1.85e-02 1.41e-02 1.10e-02 3.90e-02 3.75e-02 4.82e-02 ph/cm2/s
Fluence Cutoff-PL 9.92e-08 2.20e-07 3.82e-07 1.52e-06 1.04e-06 2.24e-06 erg/cm2
Error 2.38e-08 3.03e-08 4.99e-08 4.74e-07 1.27e-07 4.60e-07 erg/cm2
Peak flux Cutoff-PL 5.77e-02 8.02e-02 7.52e-02 8.55e-02 2.50e-01 2.98e-01 ph/cm2/s
Error 2.30e-02 1.54e-02 1.44e-02 6.15e-02 3.86e-02 6.88e-02 ph/cm2/s
Fluence Band 9.91e-08 2.20e-07 3.81e-07 1.52e-06 1.04e-06 2.20e-06 erg/cm2
Error 2.35e-08 3.01e-08 5.22e-08 4.72e-07 1.26e-07 6.82e-07 erg/cm2
Peak flux Band 3.10e-01 0.00e+00 0.00e+00 0.00e+00 0.00e+00 0.00e+00 ph/cm2/s
Error 0.00e+00 0.00e+00 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 1.208 0.213 - - 9.20e-04 1.04e-04 53.970 57
CPL 1.126 0.455 611.9 0.0 1.00e-03 4.65e-04 54.161 56
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.123 0.253 - - 2.18e-03 3.08e-04 64.648 57
CPL 0.809 0.917 217.2 4957.5 3.01e-03 4.45e-03 64.385 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: 62.464000 sec.
T50 in the 50-300 keV band: 20.864000 sec.
=== Table of the duration information ==
Value tstart tstop
T100 112.000 -15.232 96.768
T90 96.000 -15.232 80.768
T50 48.000 0.768 48.768
Peak 1.000 8.268 9.268
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
121.8857 +57.6004 0.0175 30.7 -132.9 0.9277 11.0 TRIG_00279898
------------------------------------------
Foreground time interval of the image:
-15.232 35.369 (delta_t = 50.601 [sec])
Background time interval of the image:
-239.232 -15.232 (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 -15.232 sec. to 96.768 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.20846 ( -0.215358 0.210741 )
Norm@50keV : 9.201556E-04 ( -1.038152E-04 1.035668E-04) )
------------------------------------------------------------
Chi-Squared = 53.97025 using 59 PHA bins.
Reduced chi-squared = 0.9468464 for 57 degrees of freedom
Null hypothesis probability = 0.589
Photon flux (15-150 keV) in 112.0 sec: 0.108137 ( -0.0129467 0.013023 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.04314e-06 ( -1.26231e-07 1.26881e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -15.232 sec. to 96.768 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.12619 ( -0.613033 0.296790 )
Epeak [keV] : 611.931 ( )
Norm@50keV : 1.001375E-03 ( -1.040116E-04 8.264558E-04) )
------------------------------------------------------------
Chi-Squared = 54.16133 using 59 PHA bins.
Reduced chi-squared = 0.9671666 for 56 degrees of freedom
Null hypothesis probability = 0.545
Photon flux (15-150 keV) in 112.0 sec: 0.108097 ( -0.0129428 0.013018 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.04345e-06 ( -1.2628e-07 1.26964e-07 ) ergs/cm2
Band function
Time interval is from -15.232 sec. to 96.768 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.975654 ( -9.02435 4.37487 )
beta : -1.20816 ( -0.211078 0.215005 )
Epeak [keV] : 56.2254 ( -56.1254 9943.77 )
Norm@50keV : 1.595038E-03 ( -7.781398E-04 281.586 )
------------------------------------------------------------
Chi-Squared = 53.97029 using 59 PHA bins.
Reduced chi-squared = 0.9812780 for 55 degrees of freedom
Null hypothesis probability = 0.514
Photon flux (15-150 keV) in 112.0 sec: 0.108097 ( -0.0129412 0.012994 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.04257e-06 ( -1.26155e-07 1.26744e-07 ) ergs/cm2
Peak spectrum fit using the pre-slew DRM
Power-law model
Time interval is from 0.768 sec. to 16.768 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.12268 ( -0.257736 0.247791 )
Norm@50keV : 2.176158E-03 ( -3.089954E-04 3.072890E-04) )
------------------------------------------------------------
Chi-Squared = 64.64841 using 59 PHA bins.
Reduced chi-squared = 1.134183 for 57 degrees of freedom
Null hypothesis probability = 0.227
Photon flux (15-150 keV) in 16.00 sec: 0.253002 ( -0.037438 0.03763 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.61366e-07 ( -5.38336e-08 5.4288e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.768 sec. to 16.768 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 0.808686 ( -1.28855 0.546226 )
Epeak [keV] : 217.216 ( -132.241 9782.78 )
Norm@50keV : 3.014441E-03 ( -1.121680E-03 7.775611E-03) )
------------------------------------------------------------
Chi-Squared = 64.38539 using 59 PHA bins.
Reduced chi-squared = 1.149739 for 56 degrees of freedom
Null hypothesis probability = 0.207
Photon flux (15-150 keV) in 16.00 sec: 0.250030 ( -0.038822 0.0383 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.57251e-07 ( -5.77968e-08 5.58496e-08 ) ergs/cm2
Band function
Time interval is from 0.768 sec. to 16.768 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -0.912873 ( -9.08713 5.45946 )
beta : -1.12267 ( -8.60305 0.511933 )
Epeak [keV] : 54.8808 ( -146.396 864.637 )
Norm@50keV : 3.717194E-03 ( -1.840855E-03 273.710 )
------------------------------------------------------------
Chi-Squared = 64.64841 using 59 PHA bins.
Reduced chi-squared = 1.175426 for 55 degrees of freedom
Null hypothesis probability = 0.175
Photon flux (15-150 keV) in 16.00 sec: ( ) ph/cm2/s
Energy fluence (15-150 keV) : 0 ( 0 0 ) ergs/cm2
Plot creation:
Thu Dec 13 23:12:35 EST 2007