batgrbproduct Analysis for Trigger=285948
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): Fri Dec 14 05:18:45 EST 2007
Host Name: gcn5
Current Working Dir: /local/data/raid2/prebascript/trigger285948/SDC
======================================================================
Trigger: 00285948 Segment: 000
BAT Trigger Time: 206967232.32 [s; MET]
Trigger Stop: 206967232.832 [s; MET]
UTC: 2007-07-24T10:53:50.211640 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 27.8178746741569 Dec: -18.6216425472074 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 8.71
Image Trigger?: NO
Rate S/N Ratio: 13.0384048104053 [ if not an image trigger ]
Image S/N Ratio: 8.71
Flight Position: [ source = BAT ]
RA: 27.8178746741569 Dec: -18.6216425472074 [deg; J2000]
Ground Position: [ source = BAT pre-slew burst ]
RA: 27.8272953495422 Dec: -18.6180235402332 [deg; J2000]
{ 01h 51m 18.6s , -18d 37' 04.9" }
+/- 2.31757533394098 [arcmin] (estimated 90% radius based on SNR)
+/- 1.26116013693106 [arcmin] (formal 1-sigma fit error)
SNR: 9.15464350939626
RA = 1h 51m 18.6s (27.827295 deg.)
Dec = -18d 37' 5" (-18.618024 deg.)
Angular difference between Flight and Ground position is 0.577993 arcmin
Partial Coding Fraction: 0.9140625 [ including projection effects ]
Duration
T90: 0.655999958515167 +/- 0.20799999512159
Measured from: -0.00799998641014099
to: 0.647999972105026 [s; relative to TRIGTIME]
T50: 0.27199998497963 +/- 0.115377634929687
Measured from: 0.104000002145767
to: 0.375999987125397 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: -0.171999990940094
to: 0.828000009059906 [s; relative to TRIGTIME]
Total Fluence
Measured from: -0.0399999916553497
to: 0.680000007152557 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.028641 0.023464 0.012211 0.003893
0.004248 0.004272 0.003750 0.003101 [error]
Peak 0.028344 0.024007 0.011914 0.004263
0.004288 0.004309 0.003778 0.003118 [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 7.29e-09 1.01e-08 1.04e-08 1.96e-08 3.40e-08 4.71e-08 erg/cm2
Error 1.80e-09 1.91e-09 3.38e-09 1.25e-08 7.91e-09 1.65e-08 erg/cm2
Peak flux Power-law 3.22e-01 2.48e-01 1.28e-01 9.49e-02 7.41e-01 7.92e-01 ph/cm2/s
Error 8.19e-02 4.66e-02 4.03e-02 5.64e-02 1.38e-01 1.52e-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 0.00e+00 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
Fluence Band 7.12e-09 1.10e-08 9.48e-09 1.36e-08 3.26e-08 4.13e-08 erg/cm2
Error 1.87e-09 3.54e-09 3.86e-09 9.14e-09 8.58e-09 1.92e-08 erg/cm2
Peak flux Band 3.09e-01 2.76e-01 1.18e-01 6.47e-02 7.36e-01 7.68e-01 ph/cm2/s
Error 8.97e-02 6.95e-02 4.43e-02 7.45e-02 1.05e-01 1.62e-01 ph/cm2/s
=== Time-averaged spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.956 0.341 - - 5.14e-03 1.23e-03 60.124 57
CPL 1.052 0.000 41.2 0.0 1.81e-02 0.00e+00 58.859 56
=== 1-s peak spectral analysis ===
Model Ph_index Ph_90err Epeak Epeak_90err Norm Nomr_90err chi2 dof
PL 1.956 0.344 - - 5.04e-03 1.22e-03 59.339 57
CPL 1.056 0.000 41.2 0.0 1.77e-02 0.00e+00 58.128 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 0.720 -0.040 0.680
T90 0.656 -0.008 0.648
T50 0.272 0.104 0.376
Peak 1.000 -0.172 0.828
Image
Pre-slew 15-350 keV image (Event data; bkg subtracted)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name
27.8273 -18.6180 0.0211 17.2 33.4 0.0718 9.2 TRIG_00285948
------------------------------------------
Foreground time interval of the image:
-0.040 0.680 (delta_t = 0.720 [sec])
Background time interval of the image:
-239.320 -0.040 (delta_t = 239.280 [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 -0.040 sec. to 0.680 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.95588 ( -0.324519 0.357921 )
Norm@50keV : 5.135622E-03 ( -1.254870E-03 1.213361E-03) )
------------------------------------------------------------
Chi-Squared = 60.12450 using 59 PHA bins.
Reduced chi-squared = 1.054816 for 57 degrees of freedom
Null hypothesis probability = 0.363
Photon flux (15-150 keV) in 0.7200 sec: 0.755155 ( -0.139966 0.139971 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.40105e-08 ( -7.71574e-09 8.10965e-09 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.040 sec. to 0.680 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.05157 ( )
Epeak [keV] : 41.1865 ( )
Norm@50keV : 1.812337E-02 ( )
------------------------------------------------------------
Chi-Squared = 58.85920 using 59 PHA bins.
Reduced chi-squared = 1.051057 for 56 degrees of freedom
Null hypothesis probability = 0.371
Photon flux (15-150 keV) in 0.7200 sec: ( ) ph/cm2/s
Energy fluence (15-150 keV) : 0 ( 0 0 ) ergs/cm2
Band function
Time interval is from -0.040 sec. to 0.680 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.03430 ( -8.96570 1.76516 )
beta : -9.08606 ( -0.913940 5.36711 )
Epeak [keV] : 41.0806 ( -19.1583 9958.92 )
Norm@50keV : 1.857849E-02 ( -1.857848E-02 0.314887 )
------------------------------------------------------------
Chi-Squared = 58.85953 using 59 PHA bins.
Reduced chi-squared = 1.070173 for 55 degrees of freedom
Null hypothesis probability = 0.336
Photon flux (15-150 keV) in 0.7200 sec: 0.750616 ( -0.142757 0.140647 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.25618e-08 ( -8.99971e-09 8.16242e-09 ) ergs/cm2
Peak spectrum fit using the pre-slew DRM
Power-law model
Time interval is from -0.040 sec. to 0.696 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.95563 ( -0.326680 0.360489 )
Norm@50keV : 5.040486E-03 ( -1.237790E-03 1.196086E-03) )
------------------------------------------------------------
Chi-Squared = 59.33945 using 59 PHA bins.
Reduced chi-squared = 1.041043 for 57 degrees of freedom
Null hypothesis probability = 0.390
Photon flux (15-150 keV) in 0.7360 sec: 0.741082 ( -0.13814 0.138142 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.41272e-08 ( -7.78791e-09 8.16886e-09 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.040 sec. to 0.696 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: 1.05557 ( )
Epeak [keV] : 41.2220 ( )
Norm@50keV : 1.767462E-02 ( )
------------------------------------------------------------
Chi-Squared = 58.12789 using 59 PHA bins.
Reduced chi-squared = 1.037998 for 56 degrees of freedom
Null hypothesis probability = 0.397
Photon flux (15-150 keV) in 0.7360 sec: ( ) ph/cm2/s
Energy fluence (15-150 keV) : 0 ( 0 0 ) ergs/cm2
Band function
Time interval is from -0.040 sec. to 0.696 sec.
Spectral model in the Band function:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
alpha : -1.15417 ( -12.0873 2.91266 )
beta : -4.53517 ( -0.853992 0.466341 )
Epeak [keV] : 44.7111 ( -27.3325 22.4407 )
Norm@50keV : 1.481351E-02 ( -416.185 107.898 )
------------------------------------------------------------
Chi-Squared = 58.20594 using 59 PHA bins.
Reduced chi-squared = 1.058290 for 55 degrees of freedom
Null hypothesis probability = 0.358
Photon flux (15-150 keV) in 0.7360 sec: 0.735817 ( -0.070537 0.138832 ) ph/cm2/s
Energy fluence (15-150 keV) : 3.25879e-08 ( -8.79881e-09 8.0104e-09 ) ergs/cm2
Plot creation:
Fri Dec 14 05:34:00 EST 2007