Analysis Summary
Notes:
- 1) No attempt has been made to eliminate the non-significant decimal places.
- 2) This batgrbproduct analysis is done using the HEASARC data.
- 3) This batgrbproduct analysis is using the flight position for the mask-weighting calculation.
======================================================================
BAT GRB EVENT DATA PROCESSING REPORT
Process Script Ver: batgrbproduct v2.46
Process Start Time: Sun Jan 19 19:33:32 EST 2014
Host Name: batevent1
Current Working Dir: /local/data/batevent/batevent_reproc/trigger338338
======================================================================
Trigger: 00338338 Segment: 000
BAT Trigger Time: 252119864.128 [s; MET]
Trigger Stop: 252119865.152 [s; MET]
UTC: 2008-12-28T01:17:40.758740 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 39.4673999801958 Dec: 30.842582797203 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 7.61
Image Trigger?: NO
Rate S/N Ratio: 10.6770782520313 [ if not an image trigger ]
Image S/N Ratio: 7.61
Analysis Position: [ source = BAT ]
RA: 39.4673999801958 Dec: 30.842582797203 [deg; J2000]
Refined Position: [ source = BAT pre-slew burst ]
RA: 39.4759056331836 Dec: 30.8348263027381 [deg; J2000]
{ 02h 37m 54.2s , +30d 50' 05.4" }
+/- 2.30200780377269 [arcmin] (estimated 90% radius based on SNR)
+/- 1.0858514668772 [arcmin] (formal 1-sigma fit error)
SNR: 9.24321305285686
Angular difference between the analysis and refined position is 0.639213 arcmin
Partial Coding Fraction: 0.859375 [ including projection effects ]
Duration
T90: 3 +/- 1.4142135623731
Measured from: -0.127999991178513
to: 2.87200000882149 [s; relative to TRIGTIME]
T50: 2 +/- 1
Measured from: -0.127999991178513
to: 1.87200000882149 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: -0.127999991178513
to: 0.872000008821487 [s; relative to TRIGTIME]
Total Fluence
Measured from: -0.127999991178513
to: 2.87200000882149 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.064128 0.085566 0.022239 0.001518
0.009476 0.010039 0.008531 0.007280 [error]
Peak 0.024167 0.036959 0.011511 -0.001401
0.005495 0.005914 0.005126 0.004201 [error]
[ fluence units of on-axis counts / fully illuminated detector ]
======================================================================
====== Table of the duration information =============================
Value tstart tstop
T100 3.000 -0.128 2.872
T90 3.000 -0.128 2.872
T50 2.000 -0.128 1.872
Peak 1.000 -0.128 0.872
====== Spectral Analysis Summary =====================================
Model : spectral model: simple power-law (PL) and cutoff power-law (CPL)
Ph_index : photon index: E^{Ph_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 both the PL model and CPL model
Nomr_90err : 90% error of the normalization
chi2 : Chi-Squared
dof : degree of freedo
=== Time-averaged spectral analysis ===
(Best model with acceptable fit: PL)
Model Ph_index Ph_90err_low Ph_90err_hi Epeak Epeak_90err_low Epeak_90err_hi Norm Nomr_90err_low Norm_90err_hi chi2 dof
PL -1.999 -0.309 0.284 - - - 3.35e-03 -7.09e-04 6.86e-04 56.290 57
CPL -1.014 -1.118 2.672 37.428 N/A N/A 1.37e-02 N/A N/A 55.420 56
=== 1-s peak spectral analysis ===
(Best model with acceptable fit: PL)
Model Ph_index Ph_90err_low Ph_90err_hi Epeak Epeak_90err_low Epeak_90err_hi Norm Nomr_90err_low Norm_90err_hi chi2 dof
PL -1.816 -0.399 0.365 - - - 4.49e-03 -1.20e-03 1.16e-03 54.070 57
CPL 0.642 -2.451 4.945 41.633 -9.136 93.501 1.32e-01 -1.32e-01 1.36e+02 51.250 56
=== 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 PL 2.06e-08 2.79e-08 2.79e-08 5.05e-08 9.27e-08 1.27e-07 erg/cm2
90%_error_low -4.29e-09 -4.51e-09 -7.75e-09 -2.29e-08 -1.80e-08 -3.33e-08 erg/cm2
90%_error_hi 4.38e-09 4.48e-09 8.09e-09 3.30e-08 1.87e-08 4.12e-08 erg/cm2
Peak flux PL 2.51e-01 2.09e-01 1.19e-01 1.00e-01 6.23e-01 6.79e-01 ph/cm2/s
90%_error_low -7.50e-02 -4.59e-02 -3.97e-02 -5.19e-02 -1.37e-01 -1.52e-01 ph/cm2/s
90%_error_hi 7.90e-02 4.59e-02 4.07e-02 7.69e-02 1.37e-01 1.54e-01 ph/cm2/s
Fluence CPL N/A N/A N/A N/A N/A N/A erg/cm2
90%_error_low -4.29e-09 -4.51e-09 -7.75e-09 -2.29e-08 -1.80e-08 -3.33e-08 erg/cm2
90%_error_hi 4.38e-09 4.48e-09 8.09e-09 3.30e-08 1.87e-08 4.12e-08 erg/cm2
Peak flux CPL 2.05e-01 2.73e-01 9.58e-02 5.21e-03 5.79e-01 5.79e-01 ph/cm2/s
90%_error_low -9.37e-02 -7.23e-02 -9.58e-02 -5.21e-03 -1.39e-01 -1.39e-01 ph/cm2/s
90%_error_hi 9.38e-02 8.05e-02 5.86e-02 9.32e-02 1.42e-01 1.46e-01 ph/cm2/s
======================================================================
Image
Pre-slew 15.0-350.0 keV image (Event data)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name 39.4759 30.8348 0.0208 25.9023 4.7075 0.1629767 9.243 TRIG_00338338 Foreground time interval of the image: -0.128 2.872 (delta_t = 3.000 [sec]) Background time interval of the image: -266.827 -0.128 (delta_t = 266.699 [sec])
Light Curves
Note: The mask-weighted lightcurves have units of either count/det or counts/sec/det, where a det is 0.4 x 0.4 = 0.16 sq cm.
Full-time range; 1 s binning
Other quick-look light curves:
- 64 ms binning (zoomed)
- 16 ms binning (zoomed)
- 8 ms binning (zoomed)
- 2 ms binning (zoomed)
- SN=5 or 10 s binning (full-time range)
- Raw light curve
Spectra
- 64 ms binning (zoomed)
- 16 ms binning (zoomed)
- 8 ms binning (zoomed)
- 2 ms binning (zoomed)
- SN=5 or 10 s binning (full-time range)
- Raw light curve
Spectra
Notes:
- 1) The fitting includes the systematic errors.
- 2) When the burst includes telescope slew time periods, the fitting uses an average response file made from multiple 5-s response files through out the slew time plus single time preiod for the non-slew times, and weighted by the total counts in the corresponding time period using addrmf. An average response file is needed becuase a spectral fit using 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 average DRM
Power-law model
Time interval is from -0.128 sec. to 2.872 sec. Spectral model in power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.99891 ( -0.309248 0.283642 ) Norm@50keV : 3.35209E-03 ( -0.000709289 0.0006864 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 56.29 using 59 PHA bins. # Reduced chi-squared = 0.9875 for 57 degrees of freedom # Null hypothesis probability = 5.018691e-01 Photon flux (15-150 keV) in 3 sec: 0.502599 ( -0.078992 0.078993 ) ph/cm2/s Energy fluence (15-150 keV) : 9.27474e-08 ( -1.80352e-08 1.86901e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.128 sec. to 2.872 sec. Spectral model in the cutoff power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.0142 ( -1.12531 2.66476 ) Epeak [keV] : 37.4280 ( ) Norm@50keV : 1.36890E-02 ( ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 55.42 using 59 PHA bins. # Reduced chi-squared = 0.9897 for 56 degrees of freedom # Null hypothesis probability = 4.966080e-01 Photon flux (15-150 keV) in 3 sec: 0.486886 ( -0.083335 0.084122 ) ph/cm2/s Energy fluence (15-150 keV) : 0 ( 0 0 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from -0.128 sec. to 0.872 sec. Spectral model in power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.8161 ( -0.399346 0.365052 ) Norm@50keV : 4.49016E-03 ( -0.00119946 0.0011587 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 54.07 using 59 PHA bins. # Reduced chi-squared = 0.9485 for 57 degrees of freedom # Null hypothesis probability = 5.858775e-01 Photon flux (15-150 keV) in 1 sec: 0.622671 ( -0.136615 0.136619 ) ph/cm2/s Energy fluence (15-150 keV) : 4.13228e-08 ( -1.08094e-08 1.12644e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.128 sec. to 0.872 sec. Spectral model in the cutoff power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: 0.642037 ( -2.53519 4.86066 ) Epeak [keV] : 41.6333 ( -8.8385 93.7984 ) Norm@50keV : 0.131763 ( -0.168833 136.094 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 51.25 using 59 PHA bins. # Reduced chi-squared = 0.9151 for 56 degrees of freedom # Null hypothesis probability = 6.550274e-01 Photon flux (15-150 keV) in 1 sec: 0.578799 ( -0.138729 0.142003 ) ph/cm2/s Energy fluence (15-150 keV) : 3.26829e-08 ( -9.0346e-09 1.32782e-08 ) ergs/cm2
Time-resolved spectra
Distribution
T90 vs. Hardness ratio plot
T90 = 3.0 sec. Hardness ratio (energy fluence ratio) = 1.00080616007
S(15-50 keV) vs. S(50-150 keV) plot
S(15-50 keV) = 4.846811e-08 S(50-150 keV) = 4.428122e-08
The dash-dotted line and the dashed line traces the fluences calculated from the Band function with Epeak = 15 and 150 keV, respectively. Both lines assume a canonical values of alpha = -1 and beta = -2.5.
Mask shadow pattern
IMX = 4.839855197255994E-01, IMY = -3.985472905366623E-02
Spacecraft aspect plot
Bright source in the pre-burst/pre-slew/post-slew images
Pre-burst image of 15-350 keV band
Time interval of the image: -266.827400 -0.128000 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 83.6482 21.9887 0.8 39.4 80.5 10.6897 14.4 1.8 Crab 58.5796 -17.1100 2.2 25.8 171.1 1.0297 5.2 ------ UNKNOWN 23.5281 54.1909 2.1 51.8 1.7 2.9489 5.6 ------ UNKNOWN 16.5506 0.6626 2.8 30.3 -80.1 1.1146 4.0 ------ UNKNOWN
Pre-slew background subtracted image of 15-350 keV band
Time interval of the image: -0.128000 2.872000 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 83.6424 22.0237 164.7 39.4 80.5 0.0049 0.1 0.8 Crab 76.8603 -1.7759 2.5 31.3 121.6 0.1338 4.6 ------ UNKNOWN 39.4759 30.8349 1.2 25.9 4.7 0.1630 9.2 ------ UNKNOWN 42.8218 -29.8312 2.4 35.8 -156.0 0.1007 4.9 ------ UNKNOWN
Post-slew image of 15-350 keV band
Time interval of the image: 61.972590 119.572590 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 53.5882 -19.3789 2.1 52.0 169.7 1.4407 5.5 ------ UNKNOWN 343.6584 63.4051 2.4 47.6 -23.4 0.6928 4.8 ------ UNKNOWN 10.8435 -7.4790 3.2 47.1 -132.9 0.9329 3.6 ------ UNKNOWN