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: Fri Oct 19 18:55:49 EDT 2018
Host Name: bat1
Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger850471
======================================================================
Trigger: 00850471 Segment: 000
BAT Trigger Time: 554491762.048 [s; MET]
Trigger Stop: 554491762.56 [s; MET]
UTC: 2018-07-28T17:29:00.710460 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 253.569321153668 Dec: -54.0307606838017 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 10.51
Image Trigger?: NO
Rate S/N Ratio: 19.6468827043885 [ if not an image trigger ]
Image S/N Ratio: 10.51
Analysis Position: [ source = BAT ]
RA: 253.569321153668 Dec: -54.0307606838017 [deg; J2000]
Refined Position: [ source = BAT pre-slew burst ]
RA: 253.573629224443 Dec: -54.037142488569 [deg; J2000]
{ 16h 54m 17.7s , -54d 02' 13.7" }
+/- 0.498594483330955 [arcmin] (estimated 90% radius based on SNR)
+/- 0.161336818625638 [arcmin] (formal 1-sigma fit error)
SNR: 82.206793742066
Angular difference between the analysis and refined position is 0.411904 arcmin
Partial Coding Fraction: 0.5703125 [ including projection effects ]
Duration
T90: 8.6839998960495 +/- 0.297321378474679
Measured from: 11.6720000505447
to: 20.3559999465942 [s; relative to TRIGTIME]
T50: 2.46399998664856 +/- 0.035777160144337
Measured from: 12.6840000152588
to: 15.1480000019073 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 12.6119999885559
to: 13.6119999885559 [s; relative to TRIGTIME]
Total Fluence
Measured from: -0.24399995803833
to: 36.5119999647141 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 18.317970 20.133705 11.806000 2.307044
0.102586 0.106955 0.087485 0.057004 [error]
Peak 4.769779 5.525946 3.453081 0.768668
0.046121 0.049667 0.040899 0.022944 [error]
[ fluence units of on-axis counts / fully illuminated detector ]
======================================================================
====== Table of the duration information =============================
Value tstart tstop
T100 36.756 -0.244 36.512
T90 8.684 11.672 20.356
T50 2.464 12.684 15.148
Peak 1.000 12.612 13.612
====== 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 -1.972 -0.026 0.026 - - - 8.88e-02 -1.19e-03 1.19e-03 44.770 57
CPL -1.908 -0.100 0.103 88.337 -24.649 -88.337 9.43e-02 -4.43e-03 9.20e-03 43.610 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 -1.879 -0.031 0.031 - - - 9.25e-01 -1.48e-02 1.48e-02 42.730 57
CPL -1.860 -0.048 0.120 430.784 N/A N/A 9.43e-01 N/A N/A 42.650 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 6.51e-06 8.98e-06 9.15e-06 1.70e-05 3.01e-05 4.16e-05 erg/cm2
90%_error_low -1.98e-07 -1.61e-07 -1.29e-07 -5.55e-07 -4.13e-07 -6.03e-07 erg/cm2
90%_error_hi 2.01e-07 1.61e-07 1.29e-07 5.68e-07 4.13e-07 6.07e-07 erg/cm2
Peak flux PL 5.49e+01 4.42e+01 2.40e+01 1.91e+01 1.32e+02 1.42e+02 ph/cm2/s
90%_error_low -1.94e+00 -9.28e-01 -4.23e-01 -7.33e-01 -2.85e+00 -2.70e+00 ph/cm2/s
90%_error_hi 1.98e+00 9.28e-01 4.22e-01 7.50e-01 2.87e+00 2.72e+00 ph/cm2/s
Fluence CPL 6.37e-06 8.98e-06 9.21e-06 1.60e-05 2.99e-05 4.05e-05 erg/cm2
90%_error_low -2.85e-07 -1.62e-07 -1.59e-07 -1.51e-06 -4.64e-07 -1.65e-06 erg/cm2
90%_error_hi 2.78e-07 1.62e-07 1.59e-07 1.23e-06 4.65e-07 1.43e-06 erg/cm2
Peak flux CPL N/A N/A N/A N/A N/A N/A ph/cm2/s
90%_error_low -1.94e+00 -9.28e-01 -4.23e-01 -7.33e-01 -2.85e+00 -2.70e+00 ph/cm2/s
90%_error_hi 1.98e+00 9.28e-01 4.22e-01 7.50e-01 2.87e+00 2.72e+00 ph/cm2/s
======================================================================
Image
Pre-slew 15.0-350.0 keV image (Event data)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name 253.5736 -54.0371 0.0023 35.8346 15.4028 54.2269690 82.207 TRIG_00850471 Foreground time interval of the image: -0.244 36.512 (delta_t = 36.756 [sec]) Background time interval of the image: -239.048 -0.244 (delta_t = 238.804 [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 -0.244 sec. to 36.512 sec. Spectral model in power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.97205 ( -0.0256071 0.0256499 ) Norm@50keV : 8.88207E-02 ( -0.00119416 0.00119252 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 44.77 using 59 PHA bins. # Reduced chi-squared = 0.7854 for 57 degrees of freedom # Null hypothesis probability = 8.801782e-01 Photon flux (15-150 keV) in 36.76 sec: 13.1557 ( -0.2603 0.2623 ) ph/cm2/s Energy fluence (15-150 keV) : 3.00764e-05 ( -4.1334e-07 4.12793e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.244 sec. to 36.512 sec. Spectral model in the cutoff power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.90825 ( -0.100381 0.102503 ) Epeak [keV] : 88.3366 ( -24.6494 -88.3366 ) Norm@50keV : 9.42692E-02 ( -0.00443166 0.00919912 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 43.61 using 59 PHA bins. # Reduced chi-squared = 0.7787 for 56 degrees of freedom # Null hypothesis probability = 8.861206e-01 Photon flux (15-150 keV) in 36.76 sec: ( ) ph/cm2/s Energy fluence (15-150 keV) : 2.99361e-05 ( -4.63731e-07 4.65404e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 12.612 sec. to 13.612 sec. Spectral model in power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.87901 ( -0.0310366 0.0310338 ) Norm@50keV : 0.925161 ( -0.0147612 0.0147553 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 42.73 using 59 PHA bins. # Reduced chi-squared = 0.7496 for 57 degrees of freedom # Null hypothesis probability = 9.199135e-01 Photon flux (15-150 keV) in 1 sec: 131.611 ( -2.854 2.872 ) ph/cm2/s Energy fluence (15-150 keV) : 8.50629e-06 ( -1.35624e-07 1.35625e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from 12.612 sec. to 13.612 sec. Spectral model in the cutoff power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.85975 ( -0.0478875 0.119846 ) Epeak [keV] : 430.784 ( ) Norm@50keV : 0.942773 ( ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 42.65 using 59 PHA bins. # Reduced chi-squared = 0.7616 for 56 degrees of freedom # Null hypothesis probability = 9.056243e-01 Photon flux (15-150 keV) in 1 sec: ( ) ph/cm2/s Energy fluence (15-150 keV) : 8.07477e-06 ( -2.54171e-07 1.45231e-06 ) ergs/cm2
Time-resolved spectra
Distribution
T90 vs. Hardness ratio plot
T90 = 8.684 sec. Hardness ratio (energy fluence ratio) = 1.01957692048
S(15-50 keV) vs. S(50-150 keV) plot
S(15-50 keV) = 1.5484742e-05 S(50-150 keV) = 1.4591213e-05
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 = 6.962036737757912E-01, IMY = -1.918027696107422E-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: -239.048000 -0.244000 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 170.4255 -60.5979 4.3 38.1 -58.2 1.3658 2.7 3.6 Cen X-3 187.0866 -62.7626 5.9 35.2 -45.4 0.6663 2.0 11.8 GX 301-2 255.7995 -37.8456 27.7 51.3 23.0 -0.4271 -0.4 8.9 4U 1700-377 256.3260 -36.4822 472.7 52.5 23.8 -0.0318 -0.0 6.4 GX 349+2 264.9325 -44.5267 4.3 43.3 30.3 1.3736 2.7 9.3 4U 1735-44 242.8767 -55.0027 3.2 36.5 4.8 1.0866 3.6 ------ UNKNOWN 40.1307 -29.7518 2.4 56.6 179.4 7.6049 4.9 ------ UNKNOWN 232.7111 -52.9952 3.0 40.0 -3.7 1.3410 3.9 ------ UNKNOWN 198.4931 -57.1114 2.7 39.9 -34.8 1.5030 4.3 ------ UNKNOWN
Pre-slew background subtracted image of 15-350 keV band
Time interval of the image: -0.244000 36.512000 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 170.5722 -60.7150 5.4 38.0 -58.1 -1.9348 -2.1 9.3 Cen X-3 186.4298 -62.8662 11.9 35.1 -46.0 0.6778 1.0 8.5 GX 301-2 255.9977 -37.9992 0.0 51.1 23.1 -4.4594 -2.3 9.3 4U 1700-377 256.4452 -36.4173 58.9 52.6 24.0 -0.4806 -0.2 0.6 GX 349+2 264.7000 -44.3878 10.3 43.5 30.1 1.1272 1.1 4.2 4U 1735-44 263.1401 -39.3924 2.4 48.6 29.9 8.1810 4.9 ------ UNKNOWN 23.2101 -29.4146 3.4 54.7 161.7 9.3500 3.3 ------ UNKNOWN 8.2038 -45.8874 2.7 36.7 148.4 3.2834 4.3 ------ UNKNOWN 26.8714 -29.5259 4.1 55.0 165.6 8.1146 2.8 ------ UNKNOWN 253.5736 -54.0371 0.1 35.8 15.4 54.2226 82.2 ------ UNKNOWN 56.9199 -65.1766 2.9 24.8 -149.4 1.7751 4.0 ------ UNKNOWN 62.5960 -33.4069 3.5 56.4 -157.2 7.9249 3.3 ------ UNKNOWN
Post-slew image of 15-350 keV band
Time interval of the image: 186.452590 459.052600 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 170.4000 -60.6089 2.4 36.3 -45.4 2.1455 4.8 2.6 Cen X-3 186.7483 -62.6312 6.3 34.4 -32.0 0.6022 1.8 8.7 GX 301-2 264.9515 -44.4220 4.4 47.1 40.2 2.7430 2.6 9.1 4U 1735-44 357.6996 -37.1702 3.0 45.8 138.8 3.9838 3.9 ------ UNKNOWN 277.4681 -56.4403 2.8 33.8 48.7 1.8010 4.1 ------ UNKNOWN 228.0206 -45.5413 2.3 49.7 5.5 2.8634 4.9 ------ UNKNOWN 21.1488 -67.5923 2.7 15.8 170.2 1.1026 4.3 ------ UNKNOWN 67.7953 -32.1733 3.0 55.0 -146.1 6.6082 3.8 ------ UNKNOWN