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 v2.48
Process Start Time: Sun Nov 15 19:41:01 EST 2020
Host Name: bat1
Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger993768
======================================================================
Trigger: 00993768 Segment: 000
BAT Trigger Time: 620402400 [s; MET]
Trigger Stop: 620402464 [s; MET]
UTC: 2020-08-29T13:59:34.457300 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 251.212254438923 Dec: 72.3352684295848 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 11.74
Image Trigger?: YES
Rate S/N Ratio: 0 [ if not an image trigger ]
Image S/N Ratio: 11.74
Analysis Position: [ source = BAT ]
RA: 251.212254438923 Dec: 72.3352684295848 [deg; J2000]
Refined Position: [ source = BAT pre-slew burst ]
RA: 251.139284908903 Dec: 72.3639616106839 [deg; J2000]
{ 16h 44m 33.4s , +72d 21' 50.3" }
+/- 1.82120547775213 [arcmin] (estimated 90% radius based on SNR)
+/- 0.976871840948292 [arcmin] (formal 1-sigma fit error)
SNR: 12.9174570394513
Angular difference between the analysis and refined position is 2.173964 arcmin
Partial Coding Fraction: 0.8828125 [ including projection effects ]
Duration
T90: 13.0999999046326 +/- 3.07955838522709
Measured from: -62.6679999828339
to: -49.5680000782013 [s; relative to TRIGTIME]
T50: 2.6839998960495 +/- 0.0488262872311079
Measured from: -60.5199999809265
to: -57.836000084877 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: -60.067999958992
to: -59.067999958992 [s; relative to TRIGTIME]
Total Fluence
Measured from: -74.7680000066757
to: 204.075999975204 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 11.180540 20.311526 24.369469 10.130800
0.142404 0.165589 0.171676 0.155379 [error]
Peak 1.607454 3.645324 5.388016 2.427071
0.033399 0.049304 0.061176 0.049976 [error]
[ fluence units of on-axis counts / fully illuminated detector ]
======================================================================
====== Table of the duration information =============================
Value tstart tstop
T100 278.844 -74.768 204.076
T90 13.100 -62.668 -49.568
T50 2.684 -60.520 -57.836
Peak 1.000 -60.068 -59.068
====== 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 -1.025 -0.024 0.024 - - - 1.65e-02 -2.39e-04 2.39e-04 21.290 57
CPL -0.919 -0.051 0.102 694.212 -303.848 7233.448 1.81e-02 -1.35e-03 1.60e-03 18.080 56
=== 1-s peak spectral analysis ===
(Best model with acceptable fit: CPL)
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 -0.771 -0.029 0.029 - - - 8.85e-01 -1.59e-02 1.58e-02 64.020 57
CPL -0.368 -0.126 0.130 270.821 -49.189 90.171 1.26e+00 -1.29e-01 1.46e-01 33.130 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 3.78e-06 9.30e-06 1.83e-05 8.90e-05 4.94e-05 1.20e-04 erg/cm2
90%_error_low -1.20e-07 -1.79e-07 -2.33e-07 -2.67e-06 -6.24e-07 -2.69e-06 erg/cm2
90%_error_hi 1.22e-07 1.79e-07 2.33e-07 2.73e-06 6.24e-07 2.73e-06 erg/cm2
Peak flux PL 3.06e-03 4.14e-02 7.55e-01 8.27e+01 3.41e+00 8.05e+01 ph/cm2/s
90%_error_low N/A N/A N/A N/A N/A N/A ph/cm2/s
90%_error_hi N/A N/A N/A N/A N/A N/A ph/cm2/s
Fluence CPL 3.63e-06 9.29e-06 1.85e-05 8.02e-05 4.93e-05 1.12e-04 erg/cm2
90%_error_low -1.77e-07 -1.81e-07 -3.00e-07 -7.53e-06 -6.29e-07 -7.46e-06 erg/cm2
90%_error_hi 1.79e-07 1.81e-07 3.30e-07 8.37e-06 6.27e-07 8.36e-06 erg/cm2
Peak flux CPL 1.57e+01 2.83e+01 3.52e+01 5.56e+01 1.01e+02 1.35e+02 ph/cm2/s
90%_error_low -9.59e-01 -7.07e-01 -7.93e-01 -4.83e+00 -1.79e+00 -5.20e+00 ph/cm2/s
90%_error_hi 9.83e-01 7.04e-01 7.96e-01 5.43e+00 1.80e+00 5.73e+00 ph/cm2/s
======================================================================
Image
Pre-slew 15.0-350.0 keV image (Event data)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name 251.1393 72.3640 0.0149 22.7217 -33.4050 1.8650209 12.917 TRIG_00993768 Foreground time interval of the image: -12.099 72.501 (delta_t = 84.600 [sec]) Background time interval of the image:
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 -74.768 sec. to 204.076 sec. Spectral model in power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.02508 ( -0.0239666 0.0240847 ) Norm@50keV : 1.65253E-02 ( -0.000239245 0.000238608 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared 21.29 using 59 bins. Reduced chi-squared = 0.373509 # Null hypothesis probability of 1.00e+00 with 57 degrees of freedom Photon flux (15-150 keV) in 278.8 sec: 1.90532 ( -0.02906 0.02913 ) ph/cm2/s Energy fluence (15-150 keV) : 4.93905e-05 ( -6.23901e-07 6.236e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -74.768 sec. to 204.076 sec. Spectral model in the cutoff power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -0.91937 ( -0.0506214 0.10226 ) Epeak [keV] : 694.212 ( -303.848 7233.44 ) Norm@50keV : 1.80739E-02 ( -0.00134685 0.00160187 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared 18.08 using 59 bins. Reduced chi-squared = 0.322857 # Null hypothesis probability of 1.00e+00 with 56 degrees of freedom Photon flux (15-150 keV) in 278.8 sec: 0.316846 ( -0.043777 0.032488 ) ph/cm2/s Energy fluence (15-150 keV) : 4.93245e-05 ( -6.28518e-07 6.27529e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from -60.068 sec. to -59.068 sec. Spectral model in power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -0.770524 ( -0.0288229 0.0289792 ) Norm@50keV : 0.884779 ( -0.0158786 0.0158357 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared 64.02 using 59 bins. Reduced chi-squared = 1.12316 # Null hypothesis probability of 2.44e-01 with 57 degrees of freedom Photon flux (15-150 keV) in 1 sec: 3.41045 ( ) ph/cm2/s Energy fluence (15-150 keV) : 1.04708e-05 ( -1.75713e-07 1.75777e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -60.068 sec. to -59.068 sec. Spectral model in the cutoff power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -0.36835 ( -0.12634 0.129726 ) Epeak [keV] : 270.821 ( -49.1883 90.1713 ) Norm@50keV : 1.25758 ( -0.128667 0.146315 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared 33.13 using 59 bins. Reduced chi-squared = 0.591607 # Null hypothesis probability of 9.94e-01 with 56 degrees of freedom Photon flux (15-150 keV) in 1 sec: 100.512 ( -1.7938 1.799 ) ph/cm2/s Energy fluence (15-150 keV) : 1.04674e-05 ( -1.77764e-07 1.77951e-07 ) ergs/cm2
Time-resolved spectra
Distribution
T90 vs. Hardness ratio plot
T90 = N/A sec. Hardness ratio (energy fluence ratio) = N/A
S(15-50 keV) vs. S(50-150 keV) plot
S(15-50 keV) = N/A S(50-150 keV) = N/A
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 = 3.495756185963115E-01, IMY = 2.305463279172886E-01
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:
Pre-slew background subtracted image of 15-350 keV band
Time interval of the image: -12.099400 72.500600 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 254.6293 35.2697 4.4 21.0 -150.9 0.3565 2.6 9.5 Her X-1 268.3256 -1.3882 4.9 53.2 169.2 -1.3108 -2.4 4.6 SW J1753.5-0127 288.8475 10.9404 6.8 42.8 140.1 -0.6521 -1.7 2.9 GRS 1915+105 299.6075 35.1847 2.6 25.2 104.0 0.8218 4.5 1.3 Cyg X-1 308.1355 40.9731 3.6 26.3 83.7 0.6096 3.2 1.7 Cyg X-3 326.1318 38.4348 13.8 38.9 72.0 -0.3934 -0.8 7.0 Cyg X-2 251.1394 72.3639 0.9 22.7 -33.4 1.8640 12.9 ------ UNKNOWN
Post-slew image of 15-350 keV band
Time interval of the image: 117.300590 963.094800 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 254.5869 35.3285 7.0 37.1 170.2 -1.9063 -1.6 6.4 Her X-1 301.3835 54.9474 3.1 26.9 97.8 3.8536 3.8 ------ UNKNOWN 251.2052 72.3353 1.7 0.0 -110.7 4.8972 6.9 ------ UNKNOWN 100.8998 69.3454 3.0 37.0 -22.1 3.7645 3.9 ------ UNKNOWN