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 14:29:32 EST 2018
Host Name: bat1
Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger874334
======================================================================
Trigger: 00874334 Segment: 000
BAT Trigger Time: 565425406.528 [s; MET]
Trigger Stop: 565425408.576 [s; MET]
UTC: 2018-12-02T06:36:24.513620 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 280.744790864843 Dec: 27.9509889258757 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 7.16
Image Trigger?: NO
Rate S/N Ratio: 10.9087121146357 [ if not an image trigger ]
Image S/N Ratio: 7.16
Analysis Position: [ source = BAT ]
RA: 280.744790864843 Dec: 27.9509889258757 [deg; J2000]
Refined Position: [ source = BAT pre-slew burst ]
RA: 280.737410651891 Dec: 27.9774947742065 [deg; J2000]
{ 18h 42m 57.0s , +27d 58' 39.0" }
+/- 2.01008740074281 [arcmin] (estimated 90% radius based on SNR)
+/- 1.06590351771688 [arcmin] (formal 1-sigma fit error)
SNR: 11.2190007734011
Angular difference between the analysis and refined position is 1.637737 arcmin
Partial Coding Fraction: 0.9609375 [ including projection effects ]
Duration
T90: 6.55999994277954 +/- 0.615337295582842
Measured from: 0.0199999809265137
to: 6.57999992370605 [s; relative to TRIGTIME]
T50: 4.46399998664856 +/- 0.704965200460832
Measured from: 1.05599999427795
to: 5.51999998092651 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 0.692000031471252
to: 1.69200003147125 [s; relative to TRIGTIME]
Total Fluence
Measured from: -0.25600004196167
to: 6.75600004196167 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.128191 0.170022 0.121657 0.019008
0.020796 0.021180 0.018348 0.016011 [error]
Peak 0.039340 0.046937 0.022741 0.006182
0.008107 0.008402 0.007179 0.006133 [error]
[ fluence units of on-axis counts / fully illuminated detector ]
======================================================================
====== Table of the duration information =============================
Value tstart tstop
T100 7.012 -0.256 6.756
T90 6.560 0.020 6.580
T50 4.464 1.056 5.520
Peak 1.000 0.692 1.692
====== 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 -1.602 -0.247 0.239 - - - 3.79e-03 -5.81e-04 5.71e-04 48.110 57
CPL -0.988 -0.779 1.086 76.108 -26.576 -76.108 8.12e-03 -4.74e-03 2.24e-02 46.750 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 -1.768 -0.360 0.334 - - - 6.63e-03 -1.61e-03 1.57e-03 65.980 57
CPL 0.282 -1.876 2.961 46.047 -10.430 54.402 1.01e-01 -1.01e-01 4.39e+00 62.440 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 3.73e-08 6.45e-08 8.49e-08 2.28e-07 2.48e-07 4.14e-07 erg/cm2
90%_error_low -7.82e-09 -8.99e-09 -1.72e-08 -8.24e-08 -4.07e-08 -1.01e-07 erg/cm2
90%_error_hi 8.15e-09 8.97e-09 1.73e-08 1.09e-07 4.17e-08 1.23e-07 erg/cm2
Peak flux PL 3.53e-01 3.04e-01 1.78e-01 1.57e-01 9.03e-01 9.92e-01 ph/cm2/s
90%_error_low -9.83e-02 -6.17e-02 -5.44e-02 -7.55e-02 -1.83e-01 -2.07e-01 ph/cm2/s
90%_error_hi 1.03e-01 6.17e-02 5.56e-02 1.08e-01 1.83e-01 2.10e-01 ph/cm2/s
Fluence CPL 3.46e-08 6.93e-08 8.61e-08 8.88e-08 2.35e-07 2.79e-07 erg/cm2
90%_error_low -9.05e-09 -1.09e-08 -1.91e-08 -6.37e-08 -4.40e-08 -7.96e-08 erg/cm2
90%_error_hi 9.10e-09 1.19e-08 1.90e-08 1.29e-07 4.59e-08 1.82e-07 erg/cm2
Peak flux CPL 2.89e-01 3.79e-01 1.69e-01 1.79e-02 8.53e-01 8.55e-01 ph/cm2/s
90%_error_low -1.28e-01 -9.23e-02 -7.11e-02 -1.79e-02 -1.87e-01 -1.88e-01 ph/cm2/s
90%_error_hi 1.23e-01 9.64e-02 7.02e-02 1.08e-01 1.88e-01 1.96e-01 ph/cm2/s
======================================================================
Image
Pre-slew 15.0-350.0 keV image (Event data)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name 280.7374 27.9775 0.0171 12.0798 141.0492 0.4314075 11.219 TRIG_00874334 Foreground time interval of the image: -0.256 6.756 (delta_t = 7.012 [sec]) Background time interval of the image: -781.127 -765.111 (delta_t = 16.017 [sec]) -239.528 -0.256 (delta_t = 239.272 [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 -0.256 sec. to 6.756 sec. Spectral model in power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.60212 ( -0.247205 0.239494 ) Norm@50keV : 3.78868E-03 ( -0.000581376 0.00057103 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 48.11 using 59 PHA bins. # Reduced chi-squared = 0.8441 for 57 degrees of freedom # Null hypothesis probability = 7.929621e-01 Photon flux (15-150 keV) in 7.012 sec: 0.487199 ( -0.06764 0.067664 ) ph/cm2/s Energy fluence (15-150 keV) : 2.48418e-07 ( -4.07198e-08 4.16518e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.256 sec. to 6.756 sec. Spectral model in the cutoff power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -0.988411 ( -0.77908 1.08595 ) Epeak [keV] : 76.1078 ( -26.5757 -76.1071 ) Norm@50keV : 8.12194E-03 ( -0.00473626 0.0223885 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 46.75 using 59 PHA bins. # Reduced chi-squared = 0.8348 for 56 degrees of freedom # Null hypothesis probability = 8.061345e-01 Photon flux (15-150 keV) in 7.012 sec: 0.475734 ( -0.069618 0.06963 ) ph/cm2/s Energy fluence (15-150 keV) : 2.34613e-07 ( -4.40179e-08 4.59315e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 0.692 sec. to 1.692 sec. Spectral model in power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.76772 ( -0.360491 0.333449 ) Norm@50keV : 6.63496E-03 ( -0.00161429 0.0015677 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 65.98 using 59 PHA bins. # Reduced chi-squared = 1.158 for 57 degrees of freedom # Null hypothesis probability = 1.941739e-01 Photon flux (15-150 keV) in 1 sec: 0.903134 ( -0.183428 0.183426 ) ph/cm2/s Energy fluence (15-150 keV) : 6.11801e-08 ( -1.48738e-08 1.54448e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.692 sec. to 1.692 sec. Spectral model in the cutoff power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: 0.281771 ( -1.89632 2.94003 ) Epeak [keV] : 46.0465 ( -10.3694 54.4633 ) Norm@50keV : 0.100873 ( -0.105229 4.38101 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 62.44 using 59 PHA bins. # Reduced chi-squared = 1.115 for 56 degrees of freedom # Null hypothesis probability = 2.580208e-01 Photon flux (15-150 keV) in 1 sec: 0.853061 ( -0.186867 0.188119 ) ph/cm2/s Energy fluence (15-150 keV) : 5.15146e-08 ( -1.29819e-08 1.66737e-08 ) ergs/cm2
Time-resolved spectra
Distribution
T90 vs. Hardness ratio plot
T90 = 6.56 sec. Hardness ratio (energy fluence ratio) = 1.31758879533
S(15-50 keV) vs. S(50-150 keV) plot
S(15-50 keV) = 1.0179807e-07 S(50-150 keV) = 1.4662363e-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 = -1.664353036938762E-01, IMY = -1.345400180022847E-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: -781.127400 -765.110600 -239.528000 -0.256000 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 254.4765 35.3028 3.3 15.8 26.8 1.0681 3.5 2.6 Her X-1 268.2626 -1.5324 6.2 26.0 -110.4 -0.7375 -1.9 7.9 SW J1753.5-0127 273.9199 -14.1626 6.4 39.1 -118.8 1.1959 1.8 9.1 GX 17+2 288.8338 10.9643 3.7 24.1 -168.9 0.9477 3.2 2.4 GRS 1915+105 299.5792 35.2144 2.0 29.4 131.8 2.7486 5.8 0.9 Cyg X-1 308.1490 40.9877 4.1 37.3 124.3 2.5167 2.8 2.7 Cyg X-3 310.8494 45.1455 3.8 40.3 118.7 3.4591 3.0 ------ UNKNOWN 219.8286 47.6830 2.2 44.2 24.8 2.9799 5.1 ------ UNKNOWN 227.1574 33.9496 3.5 36.5 5.2 1.4095 3.3 ------ UNKNOWN 213.4333 7.8352 3.7 54.5 -27.5 2.9984 3.1 ------ UNKNOWN 233.6614 -6.4685 2.8 45.5 -57.9 5.7294 4.2 ------ UNKNOWN 254.9586 -14.3194 2.4 40.8 -90.1 7.2695 4.7 ------ UNKNOWN
Pre-slew background subtracted image of 15-350 keV band
Time interval of the image: -0.256000 6.756000 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 254.2598 35.2950 8.3 15.9 26.4 0.0535 1.4 10.1 Her X-1 268.4666 -1.5752 88.4 26.1 -110.8 0.0067 0.1 9.4 SW J1753.5-0127 274.0799 -14.0569 3.5 39.0 -119.0 -0.2719 -3.3 4.5 GX 17+2 288.8137 10.8798 5.9 24.1 -168.7 0.0784 2.0 4.0 GRS 1915+105 299.4145 35.1361 5.1 29.2 131.9 0.1322 2.3 9.5 Cyg X-1 308.1172 40.7370 0.0 37.2 124.7 0.2511 2.4 12.9 Cyg X-3 265.8694 52.2342 2.5 27.8 68.0 0.2534 4.6 ------ UNKNOWN 280.7375 27.9775 1.0 12.1 141.0 0.4313 11.2 ------ UNKNOWN 269.2302 -18.2343 2.3 42.7 -111.4 0.8569 5.1 ------ UNKNOWN
Post-slew image of 15-350 keV band
Time interval of the image: 68.572600 962.609400 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 254.4410 35.3340 2.0 23.5 -10.3 4.9408 5.9 1.0 Her X-1 268.4356 -1.3192 15.2 31.6 -101.2 1.0195 0.8 9.0 SW J1753.5-0127 273.8766 -13.9983 7.3 42.5 -115.3 -5.7549 -1.6 7.9 GX 17+2 288.8059 10.9845 1.9 18.6 -150.8 4.9834 6.2 2.4 GRS 1915+105 299.5903 35.1724 1.2 17.6 115.8 8.6680 9.6 1.8 Cyg X-1 308.1468 40.9252 1.4 25.9 107.6 9.4748 8.1 2.3 Cyg X-3 326.0824 38.4245 8.5 38.9 117.2 3.8546 1.4 7.5 Cyg X-2 286.8548 58.6246 2.2 31.0 61.0 6.4837 5.2 ------ UNKNOWN 233.3476 50.2277 2.6 42.0 10.1 5.1213 4.4 ------ UNKNOWN 318.0706 -4.2570 2.6 48.3 -179.3 7.9146 4.5 ------ UNKNOWN 236.7380 21.5906 3.2 40.2 -34.2 4.4494 3.6 ------ UNKNOWN 211.8017 28.8483 2.6 59.7 -16.4 23.2522 4.4 ------ UNKNOWN 230.9106 12.9002 3.6 48.7 -42.7 11.0811 3.2 ------ UNKNOWN 283.8719 -19.9559 2.6 48.0 -129.2 17.7983 4.5 ------ UNKNOWN 236.0370 6.7289 3.6 47.3 -53.3 13.1852 3.2 ------ UNKNOWN