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: Mon Dec 17 17:32:18 EST 2018
Host Name: bat1
Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger868312
======================================================================
Trigger: 00868312 Segment: 000
BAT Trigger Time: 561922234.944 [s; MET]
Trigger Stop: 561922240.448 [s; MET]
UTC: 2018-10-22T17:30:13.147700 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 56.7952243531036 Dec: -29.3323371797094 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 7.23
Image Trigger?: NO
Rate S/N Ratio: 13.0384048104053 [ if not an image trigger ]
Image S/N Ratio: 7.23
Analysis Position: [ source = BAT ]
RA: 56.7952243531036 Dec: -29.3323371797094 [deg; J2000]
Refined Position: [ source = BAT pre-slew burst ]
RA: 56.8262198756328 Dec: -29.3380471074766 [deg; J2000]
{ 03h 47m 18.3s , -29d 20' 17.0" }
+/- 2.96330368269607 [arcmin] (estimated 90% radius based on SNR)
+/- 1.46562194103079 [arcmin] (formal 1-sigma fit error)
SNR: 6.44395406680995
Angular difference between the analysis and refined position is 1.657058 arcmin
Partial Coding Fraction: 1.03125 [ including projection effects ]
Duration
T90: 7.93599998950958 +/- 2.58436520285285
Measured from: -1.15600001811981
to: 6.77999997138977 [s; relative to TRIGTIME]
T50: 3.73599994182587 +/- 2.07183882053921
Measured from: 1.21200001239777
to: 4.94799995422363 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 4.40400004386902
to: 5.40400004386902 [s; relative to TRIGTIME]
Total Fluence
Measured from: -1.64400005340576
to: 7.96399998664856 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.059566 0.082269 0.095226 0.057324
0.020402 0.021639 0.020195 0.018604 [error]
Peak 0.009475 0.015498 0.024105 0.017462
0.006506 0.007154 0.006987 0.006166 [error]
[ fluence units of on-axis counts / fully illuminated detector ]
======================================================================
====== Table of the duration information =============================
Value tstart tstop
T100 9.608 -1.644 7.964
T90 7.936 -1.156 6.780
T50 3.736 1.212 4.948
Peak 1.000 4.404 5.404
====== 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 -0.962 -0.426 0.463 - - - 1.79e-03 -4.30e-04 4.25e-04 59.860 57
CPL -0.723 0.723 1.983 303.025 -303.025 -303.025 2.29e-03 -9.14e-04 1.12e-02 59.880 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 -1.192 -0.646 0.635 - - - 3.54e-03 -1.35e-03 1.34e-03 59.160 57
CPL 1.111 -3.371 -1.111 75.448 -24.641 -75.448 3.81e-02 -3.81e-02 1.05e+02 57.790 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 1.33e-08 3.40e-08 6.97e-08 3.63e-07 1.88e-07 4.80e-07 erg/cm2
90%_error_low -6.03e-09 -1.02e-08 -1.88e-08 -1.82e-07 -4.89e-08 -1.97e-07 erg/cm2
90%_error_hi 7.08e-09 9.73e-09 1.84e-08 2.96e-07 4.97e-08 2.98e-07 erg/cm2
Peak flux PL 1.08e-01 1.31e-01 1.15e-01 1.72e-01 4.15e-01 5.26e-01 ph/cm2/s
90%_error_low -6.25e-02 -5.54e-02 -5.22e-02 -1.17e-01 -1.58e-01 -2.09e-01 ph/cm2/s
90%_error_hi 7.60e-02 5.39e-02 5.10e-02 2.04e-01 1.58e-01 2.29e-01 ph/cm2/s
Fluence CPL 1.30e-08 3.42e-08 7.03e-08 3.23e-07 1.87e-07 3.67e-07 erg/cm2
90%_error_low -7.92e-09 -1.02e-08 -1.93e-08 N/A -5.25e-08 -2.09e-07 erg/cm2
90%_error_hi 5.73e-09 1.09e-08 2.26e-08 N/A 5.03e-08 3.96e-07 erg/cm2
Peak flux CPL 5.82e-02 1.44e-01 1.43e-01 4.04e-02 3.79e-01 3.86e-01 ph/cm2/s
90%_error_low -5.82e-02 -1.12e-01 N/A -4.04e-02 -1.88e-01 -1.95e-01 ph/cm2/s
90%_error_hi 1.03e-01 7.01e-02 N/A 1.90e-01 1.69e-01 2.58e-01 ph/cm2/s
======================================================================
Image
Pre-slew 15.0-350.0 keV image (Event data)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name 56.8262 -29.3380 0.0298 1.0725 136.9050 0.2607231 6.444 TRIG_00868312 Foreground time interval of the image: -1.644 7.964 (delta_t = 9.608 [sec]) Background time interval of the image: -239.944 -1.644 (delta_t = 238.300 [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 -1.644 sec. to 7.964 sec. Spectral model in power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -0.96189 ( -0.426004 0.462632 ) Norm@50keV : 1.78590E-03 ( -0.000429643 0.000425131 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 59.86 using 59 PHA bins. # Reduced chi-squared = 1.050 for 57 degrees of freedom # Null hypothesis probability = 3.722022e-01 Photon flux (15-150 keV) in 9.608 sec: 0.205262 ( -0.049519 0.049805 ) ph/cm2/s Energy fluence (15-150 keV) : 1.88136e-07 ( -4.88645e-08 4.97028e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -1.644 sec. to 7.964 sec. Spectral model in the cutoff power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -0.955856 ( 0.737134 1.99715 ) Epeak [keV] : 9987.73 ( -9960.41 -9960.41 ) Norm@50keV : 1.79704E-03 ( -0.000423718 0.0116876 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 59.86 using 59 PHA bins. # Reduced chi-squared = 1.069 for 56 degrees of freedom # Null hypothesis probability = 3.374076e-01 Photon flux (15-150 keV) in 9.608 sec: 0.204505 ( -0.051965 0.050372 ) ph/cm2/s Energy fluence (15-150 keV) : 1.8725e-07 ( -5.25021e-08 5.03205e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 4.404 sec. to 5.404 sec. Spectral model in power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.19232 ( -0.645684 0.635132 ) Norm@50keV : 3.53582E-03 ( -0.00135222 0.00134487 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 59.16 using 59 PHA bins. # Reduced chi-squared = 1.038 for 57 degrees of freedom # Null hypothesis probability = 3.967057e-01 Photon flux (15-150 keV) in 1 sec: 0.414595 ( -0.157749 0.158047 ) ph/cm2/s Energy fluence (15-150 keV) : 3.59534e-08 ( -1.52033e-08 1.57918e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 4.404 sec. to 5.404 sec. Spectral model in the cutoff power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: 1.11123 ( -3.41279 -1.15332 ) Epeak [keV] : 75.4480 ( -24.3332 -75.1398 ) Norm@50keV : 3.80843E-02 ( -0.040345 104.644 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 57.79 using 59 PHA bins. # Reduced chi-squared = 1.032 for 56 degrees of freedom # Null hypothesis probability = 4.090747e-01 Photon flux (15-150 keV) in 1 sec: 0.378558 ( -0.187768 0.169491 ) ph/cm2/s Energy fluence (15-150 keV) : 3.26926e-08 ( -1.39884e-08 1.64027e-08 ) ergs/cm2
Time-resolved spectra
Distribution
T90 vs. Hardness ratio plot
T90 = 7.936 sec. Hardness ratio (energy fluence ratio) = 2.05352487451
S(15-50 keV) vs. S(50-150 keV) plot
S(15-50 keV) = 4.723535e-08 S(50-150 keV) = 1.4090277e-07
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 = -1.367079274893475E-02, IMY = -1.279064624783077E-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: -239.944000 -1.644000 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 13.7721 -26.7913 2.4 37.7 40.1 2.1671 4.7 ------ UNKNOWN 9.1182 -30.5130 2.9 40.8 32.9 1.8259 4.0 ------ UNKNOWN 334.0981 -66.4745 3.0 59.5 -17.0 5.5291 3.8 ------ UNKNOWN
Pre-slew background subtracted image of 15-350 keV band
Time interval of the image: -1.644000 7.964000 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 353.5549 -41.9435 2.4 51.2 14.1 0.5963 4.8 ------ UNKNOWN 56.8262 -29.3380 1.8 1.1 136.9 0.2606 6.4 ------ UNKNOWN 23.1272 -70.6138 2.2 44.3 -29.1 0.3914 5.3 ------ UNKNOWN 110.9287 -6.9261 2.5 55.8 -147.7 1.0819 4.5 ------ UNKNOWN
Post-slew image of 15-350 keV band
Time interval of the image: 76.356600 962.171100 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 354.2107 -32.4129 3.2 53.0 19.5 10.3026 3.7 ------ UNKNOWN 5.7383 -30.4144 3.2 43.9 25.1 4.2180 3.6 ------ UNKNOWN 352.1845 -47.7740 3.0 52.1 0.0 5.3932 3.9 ------ UNKNOWN 92.0481 -42.8151 4.7 31.2 -105.0 2.5897 2.4 ------ UNKNOWN