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: Thu Mar 21 15:12:11 EDT 2019
Host Name: bat1
Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger887579
======================================================================
Trigger: 00887579 Segment: 000
BAT Trigger Time: 570951983.104 [s; MET]
Trigger Stop: 570951984.128 [s; MET]
UTC: 2019-02-04T05:46:00.743560 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 351.53388272963 Dec: 54.8827857064406 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 13.71
Image Trigger?: NO
Rate S/N Ratio: 34.0440890610984 [ if not an image trigger ]
Image S/N Ratio: 13.71
Analysis Position: [ source = BAT ]
RA: 351.53388272963 Dec: 54.8827857064406 [deg; J2000]
Refined Position: [ source = BAT pre-slew burst ]
RA: 351.490917880434 Dec: 54.8840662348078 [deg; J2000]
{ 23h 25m 57.8s , +54d 53' 02.6" }
+/- 0.63918515280368 [arcmin] (estimated 90% radius based on SNR)
+/- 0.284190923996894 [arcmin] (formal 1-sigma fit error)
SNR: 57.6493683991354
Angular difference between the analysis and refined position is 1.484900 arcmin
Partial Coding Fraction: 0.484375 [ including projection effects ]
Duration
T90: 26.3239998817444 +/- 7.5497881100902
Measured from: -2.58799982070923
to: 23.7360000610352 [s; relative to TRIGTIME]
T50: 3.90399992465973 +/- 0.202267160392584
Measured from: 4.10800015926361
to: 8.01200008392334 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 4.86400008201599
to: 5.86400008201599 [s; relative to TRIGTIME]
Total Fluence
Measured from: -6.51999998092651
to: 54.1280000209808 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 4.090194 6.313829 5.733352 1.794411
0.087098 0.097479 0.091729 0.074978 [error]
Peak 0.678107 1.250780 1.302533 0.464995
0.023955 0.031526 0.032949 0.023916 [error]
[ fluence units of on-axis counts / fully illuminated detector ]
======================================================================
====== Table of the duration information =============================
Value tstart tstop
T100 60.648 -6.520 54.128
T90 26.324 -2.588 23.736
T50 3.904 4.108 8.012
Peak 1.000 4.864 5.864
====== 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 -1.287 -0.038 0.038 - - - 2.07e-02 -4.19e-04 4.19e-04 48.720 57
CPL -1.166 -0.123 0.155 414.106 -197.924 -414.106 2.33e-02 -2.72e-03 3.68e-03 46.870 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 -1.103 -0.050 0.050 - - - 2.59e-01 -7.42e-03 7.42e-03 63.370 57
CPL -0.758 -0.201 0.211 210.390 -57.869 199.938 3.67e-01 -6.59e-02 8.42e-02 54.580 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 1.31e-06 2.75e-06 4.51e-06 1.67e-05 1.25e-05 2.53e-05 erg/cm2
90%_error_low -5.76e-08 -7.04e-08 -1.01e-07 -8.82e-07 -2.57e-07 -9.19e-07 erg/cm2
90%_error_hi 5.88e-08 7.03e-08 1.01e-07 9.16e-07 2.57e-07 9.47e-07 erg/cm2
Peak flux PL 2.01e-03 3.05e-02 2.62e-01 3.05e+01 1.16e+00 2.99e+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 1.27e-06 2.76e-06 4.57e-06 1.44e-05 1.24e-05 2.30e-05 erg/cm2
90%_error_low -7.89e-08 -7.21e-08 -1.22e-07 -2.39e-06 -2.74e-07 -2.38e-06 erg/cm2
90%_error_hi 6.90e-08 7.23e-08 1.23e-07 2.50e-06 2.73e-07 2.53e-06 erg/cm2
Peak flux CPL 6.64e+00 9.45e+00 9.04e+00 1.03e+01 2.96e+01 3.54e+01 ph/cm2/s
90%_error_low -5.46e-01 -3.49e-01 -3.46e-01 -1.71e+00 -9.26e-01 -1.98e+00 ph/cm2/s
90%_error_hi 5.59e-01 3.50e-01 3.49e-01 2.13e+00 9.27e-01 2.32e+00 ph/cm2/s
======================================================================
Image
Pre-slew 15.0-350.0 keV image (Event data)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name 351.4909 54.8841 0.0033 31.2759 145.8693 16.4541058 57.649 TRIG_00887579 Foreground time interval of the image: -6.520 9.997 (delta_t = 16.517 [sec]) Background time interval of the image: -234.104 -6.520 (delta_t = 227.584 [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 -6.520 sec. to 54.128 sec. Spectral model in power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.28654 ( -0.0381907 0.0382842 ) Norm@50keV : 2.07190E-02 ( -0.000419367 0.000418838 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 48.72 using 59 PHA bins. # Reduced chi-squared = 0.8547 for 57 degrees of freedom # Null hypothesis probability = 7.744700e-01 Photon flux (15-150 keV) in 60.65 sec: 2.46583 ( -0.05557 0.05573 ) ph/cm2/s Energy fluence (15-150 keV) : 1.24604e-05 ( -2.56681e-07 2.56819e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -6.520 sec. to 54.128 sec. Spectral model in the cutoff power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.1663 ( -0.123463 0.155335 ) Epeak [keV] : 414.106 ( -197.924 -414.106 ) Norm@50keV : 2.32831E-02 ( -0.0027235 0.00368067 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 46.87 using 59 PHA bins. # Reduced chi-squared = 0.8370 for 56 degrees of freedom # Null hypothesis probability = 8.024540e-01 Photon flux (15-150 keV) in 60.65 sec: 2.44312 ( -0.06176 0.06203 ) ph/cm2/s Energy fluence (15-150 keV) : 1.23849e-05 ( -2.73829e-07 2.73315e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 4.864 sec. to 5.864 sec. Spectral model in power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.10251 ( -0.0503219 0.0504505 ) Norm@50keV : 0.259034 ( -0.00741892 0.00741594 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 63.37 using 59 PHA bins. # Reduced chi-squared = 1.112 for 57 degrees of freedom # Null hypothesis probability = 2.619619e-01 Photon flux (15-150 keV) in 1 sec: 1.16024 ( ) ph/cm2/s Energy fluence (15-150 keV) : 2.70639e-06 ( -8.41647e-08 8.42897e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 4.864 sec. to 5.864 sec. Spectral model in the cutoff power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -0.758025 ( -0.201403 0.210817 ) Epeak [keV] : 210.390 ( -57.869 199.937 ) Norm@50keV : 0.366799 ( -0.0659268 0.0842303 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 54.58 using 59 PHA bins. # Reduced chi-squared = 0.9747 for 56 degrees of freedom # Null hypothesis probability = 5.287088e-01 Photon flux (15-150 keV) in 1 sec: 29.5863 ( -0.9258 0.9269 ) ph/cm2/s Energy fluence (15-150 keV) : 2.66876e-06 ( -8.83424e-08 8.80701e-08 ) ergs/cm2
Time-resolved spectra
Distribution
T90 vs. Hardness ratio plot
T90 = 26.324 sec. Hardness ratio (energy fluence ratio) = 1.63975893897
S(15-50 keV) vs. S(50-150 keV) plot
S(15-50 keV) = 4.066439e-06 S(50-150 keV) = 8.393778e-06
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 = -5.028088987541257E-01, IMY = -3.408205251257561E-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: -234.104000 -6.520000 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 254.4106 35.3527 3.6 41.8 16.0 1.6293 3.2 2.4 Her X-1 268.1581 -1.3831 5.7 56.0 -33.1 3.1148 2.1 13.3 SW J1753.5-0127 288.8638 10.9812 3.2 34.8 -49.4 1.4901 3.6 4.4 GRS 1915+105 299.5850 35.2042 0.4 9.1 -34.5 8.6133 31.7 0.3 Cyg X-1 308.1571 40.9966 3.6 0.5 -93.7 0.7975 3.2 3.4 Cyg X-3 326.2146 38.4649 8.8 14.2 -167.5 0.3430 1.3 8.8 Cyg X-2 14.6638 44.4317 2.5 47.5 159.0 3.5478 4.6 ------ UNKNOWN 301.0053 61.2830 2.4 20.3 86.4 1.4215 4.7 ------ UNKNOWN 248.4909 25.9489 2.7 50.9 8.2 2.9938 4.3 ------ UNKNOWN 256.9440 8.8691 3.0 55.5 -14.8 3.2303 3.9 ------ UNKNOWN
Pre-slew background subtracted image of 15-350 keV band
Time interval of the image: -6.520000 9.996600 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 254.3173 35.2856 5.6 41.9 16.0 -0.6687 -2.1 7.7 Her X-1 268.4692 -1.5526 9.8 56.0 -33.6 -0.8675 -1.2 8.5 SW J1753.5-0127 288.6743 10.8856 5.4 35.0 -49.2 0.5496 2.1 8.1 GRS 1915+105 299.7406 35.3449 8.8 8.9 -34.4 0.2561 1.3 11.3 Cyg X-1 308.1783 40.8873 19.4 0.6 -93.4 0.0987 0.6 5.0 Cyg X-3 326.2712 38.3710 22.8 14.3 -167.2 0.0894 0.5 5.5 Cyg X-2 351.4909 54.8841 0.2 31.3 145.9 16.4544 57.7 ------ UNKNOWN 274.9067 16.4047 2.6 37.9 -25.2 1.0653 4.5 ------ UNKNOWN 3.9349 10.7277 2.9 57.6 -158.3 4.3618 3.9 ------ UNKNOWN 313.5476 1.0216 3.0 40.8 -92.2 2.3834 3.8 ------ UNKNOWN
Post-slew image of 15-350 keV band
Time interval of the image: 63.596600 967.930200 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 299.5597 35.2211 0.5 40.4 -40.3 31.6099 24.2 1.9 Cyg X-1 307.9164 41.0173 14.3 31.7 -40.8 0.8283 0.8 9.6 Cyg X-3 326.1593 38.2916 26.1 23.8 -66.9 -0.4520 -0.4 1.9 Cyg X-2 63.2936 52.8501 3.6 40.5 118.8 10.3647 3.3 ------ UNKNOWN 54.3426 33.8826 3.7 47.6 145.9 8.0863 3.1 ------ UNKNOWN 40.8338 61.4015 1.7 26.2 112.2 7.4540 6.9 ------ UNKNOWN 40.3918 50.4065 3.0 29.4 135.0 4.3387 3.8 ------ UNKNOWN 264.4833 51.0857 2.5 49.1 0.6 6.8167 4.7 ------ UNKNOWN 258.3714 44.1072 3.0 56.9 -2.1 11.0559 3.8 ------ UNKNOWN 291.0153 48.8435 2.9 36.6 -16.9 3.9289 4.0 ------ UNKNOWN 299.5635 24.5765 2.8 48.5 -50.2 15.9047 4.1 ------ UNKNOWN