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 26 17:11:16 EDT 2018
Host Name: bat1
Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger850231
======================================================================
Trigger: 00850231 Segment: 000
BAT Trigger Time: 554393750.016 [s; MET]
Trigger Stop: 554393751.04 [s; MET]
UTC: 2018-07-27T14:15:28.684460 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 346.638589844321 Dec: -63.0635521810573 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 18.03
Image Trigger?: NO
Rate S/N Ratio: 49.2138191974571 [ if not an image trigger ]
Image S/N Ratio: 18.03
Analysis Position: [ source = BAT ]
RA: 346.638589844321 Dec: -63.0635521810573 [deg; J2000]
Refined Position: [ source = BAT pre-slew burst ]
RA: 346.638682341704 Dec: -63.066072614268 [deg; J2000]
{ 23h 06m 33.3s , -63d 03' 57.9" }
+/- 1.11315718085439 [arcmin] (estimated 90% radius based on SNR)
+/- 0.378013336151439 [arcmin] (formal 1-sigma fit error)
SNR: 26.0981128886752
Angular difference between the analysis and refined position is 0.151247 arcmin
Partial Coding Fraction: 0.859375 [ including projection effects ]
Duration
T90: 1.05599999427795 +/- 0.229120086267606
Measured from: 0.0239999294281006
to: 1.07999992370605 [s; relative to TRIGTIME]
T50: 0.452000021934509 +/- 0.0707672428107233
Measured from: 0.25599992275238
to: 0.70799994468689 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: -0.0520000457763672
to: 0.947999954223633 [s; relative to TRIGTIME]
Total Fluence
Measured from: -0.0520000457763672
to: 1.33200001716614 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.148990 0.193082 0.134374 0.018533
0.009851 0.010739 0.009288 0.006924 [error]
Peak 0.129810 0.175371 0.126329 0.017944
0.008712 0.009849 0.008540 0.006074 [error]
[ fluence units of on-axis counts / fully illuminated detector ]
======================================================================
====== Table of the duration information =============================
Value tstart tstop
T100 1.384 -0.052 1.332
T90 1.056 0.024 1.080
T50 0.452 0.256 0.708
Peak 1.000 -0.052 0.948
====== 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: 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 -1.599 -0.106 0.105 - - - 2.27e-02 -1.51e-03 1.50e-03 57.460 57
CPL -0.588 -0.484 0.546 67.627 -9.583 20.056 7.58e-02 -3.27e-02 6.75e-02 43.230 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 -1.540 -0.103 0.102 - - - 2.87e-02 -1.89e-03 1.88e-03 69.570 57
CPL -0.449 -0.480 0.542 69.677 -9.466 18.474 1.05e-01 -4.45e-02 9.11e-02 52.330 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 4.40e-08 7.62e-08 1.01e-07 2.71e-07 2.94e-07 4.91e-07 erg/cm2
90%_error_low -4.31e-09 -4.87e-09 -8.73e-09 -4.55e-08 -2.10e-08 -5.39e-08 erg/cm2
90%_error_hi 4.42e-09 4.87e-09 8.73e-09 5.10e-08 2.11e-08 5.82e-08 erg/cm2
Peak flux PL 1.23e+00 1.21e+00 8.29e-01 8.98e-01 3.62e+00 4.16e+00 ph/cm2/s
90%_error_low -1.22e-01 -7.90e-02 -6.79e-02 -1.37e-01 -2.30e-01 -2.67e-01 ph/cm2/s
90%_error_hi 1.25e-01 7.88e-02 6.76e-02 1.50e-01 2.30e-01 2.67e-01 ph/cm2/s
Fluence CPL 3.78e-08 8.48e-08 1.05e-07 7.65e-08 2.74e-07 3.05e-07 erg/cm2
90%_error_low -5.22e-09 -6.37e-09 -1.01e-08 -3.11e-08 -2.25e-08 -3.79e-08 erg/cm2
90%_error_hi 5.28e-09 6.52e-09 1.01e-08 5.47e-08 2.29e-08 5.69e-08 erg/cm2
Peak flux CPL 1.02e+00 1.34e+00 9.00e-01 3.21e-01 3.50e+00 3.59e+00 ph/cm2/s
90%_error_low -1.48e-01 -1.00e-01 -8.03e-02 -1.13e-01 -2.37e-01 -2.65e-01 ph/cm2/s
90%_error_hi 1.51e-01 1.03e-01 8.13e-02 1.67e-01 2.37e-01 2.79e-01 ph/cm2/s
======================================================================
Image
Pre-slew 15.0-350.0 keV image (Event data)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name 346.6387 -63.0661 0.0074 16.9953 53.7999 0.5245691 26.098 TRIG_00850231 Foreground time interval of the image: -0.052 1.332 (delta_t = 1.384 [sec]) Background time interval of the image: -239.016 -0.052 (delta_t = 238.964 [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 -0.052 sec. to 1.332 sec. Spectral model in power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.59876 ( -0.106402 0.104776 ) Norm@50keV : 2.27103E-02 ( -0.00151234 0.00150414 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 57.46 using 59 PHA bins. # Reduced chi-squared = 1.008 for 57 degrees of freedom # Null hypothesis probability = 4.580432e-01 Photon flux (15-150 keV) in 1.384 sec: 2.91736 ( -0.18526 0.18537 ) ph/cm2/s Energy fluence (15-150 keV) : 2.94034e-07 ( -2.09874e-08 2.11446e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.052 sec. to 1.332 sec. Spectral model in the cutoff power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -0.588052 ( -0.484203 0.545776 ) Epeak [keV] : 67.6269 ( -9.58309 20.0558 ) Norm@50keV : 7.57856E-02 ( -0.0326754 0.0674652 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 43.23 using 59 PHA bins. # Reduced chi-squared = 0.7720 for 56 degrees of freedom # Null hypothesis probability = 8.940943e-01 Photon flux (15-150 keV) in 1.384 sec: 2.80723 ( -0.19251 0.19236 ) ph/cm2/s Energy fluence (15-150 keV) : 2.74377e-07 ( -2.253e-08 2.28968e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from -0.052 sec. to 0.948 sec. Spectral model in power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.54038 ( -0.103043 0.101711 ) Norm@50keV : 2.86945E-02 ( -0.00188634 0.00187848 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 69.57 using 59 PHA bins. # Reduced chi-squared = 1.220 for 57 degrees of freedom # Null hypothesis probability = 1.227152e-01 Photon flux (15-150 keV) in 1 sec: 3.62263 ( -0.23014 0.23025 ) ph/cm2/s Energy fluence (15-150 keV) : 2.70545e-07 ( -1.92407e-08 1.93695e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.052 sec. to 0.948 sec. Spectral model in the cutoff power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -0.44936 ( -0.479801 0.541507 ) Epeak [keV] : 69.6771 ( -9.46611 18.4737 ) Norm@50keV : 0.104544 ( -0.0445468 0.0910979 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 52.33 using 59 PHA bins. # Reduced chi-squared = 0.9344 for 56 degrees of freedom # Null hypothesis probability = 6.146787e-01 Photon flux (15-150 keV) in 1 sec: 3.49799 ( -0.23704 0.23674 ) ph/cm2/s Energy fluence (15-150 keV) : 2.53087e-07 ( -2.04654e-08 2.07297e-08 ) ergs/cm2
Time-resolved spectra
Distribution
T90 vs. Hardness ratio plot
T90 = 1.056 sec. Hardness ratio (energy fluence ratio) = 1.24273963622
S(15-50 keV) vs. S(50-150 keV) plot
S(15-50 keV) = 1.2258668e-07 S(50-150 keV) = 1.5179096e-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 = 1.805139349500686E-01, IMY = -2.466397747629926E-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: -239.016000 -0.052000 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 170.0935 -60.5779 25.5 58.2 -24.4 0.6764 0.5 7.1 Cen X-3 186.8030 -62.7862 4.4 57.9 -14.8 3.0083 2.6 4.1 GX 301-2 303.6396 -58.1132 2.5 38.2 49.4 2.2344 4.6 ------ UNKNOWN 56.0102 -39.8771 3.0 29.1 -122.2 1.2008 3.9 ------ UNKNOWN 68.9322 -48.9315 3.2 29.2 -95.5 1.2710 3.6 ------ UNKNOWN 60.5981 -16.9365 2.7 50.9 -135.4 6.1991 4.3 ------ UNKNOWN
Pre-slew background subtracted image of 15-350 keV band
Time interval of the image: -0.052000 1.332000 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 170.5887 -60.5932 3.9 58.3 -24.2 -0.3032 -3.0 8.2 Cen X-3 186.4959 -62.7253 4.7 58.0 -14.9 0.2104 2.4 5.2 GX 301-2 331.1148 -36.1819 2.3 39.2 95.5 0.3598 5.1 ------ UNKNOWN 7.6073 -9.3519 2.0 50.5 155.6 0.4032 5.7 ------ UNKNOWN 346.6387 -63.0661 0.4 17.0 53.8 0.5246 26.1 ------ UNKNOWN 55.0236 -36.3595 2.1 31.5 -127.5 0.1300 5.6 ------ UNKNOWN 114.3485 -56.5370 2.3 45.8 -57.3 0.3397 5.0 ------ UNKNOWN
Post-slew image of 15-350 keV band
Time interval of the image: 55.684610 363.104000 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 186.8624 -62.8153 6.1 53.2 -28.0 -1.1028 -1.9 6.3 GX 301-2 264.8770 -44.4279 5.3 47.9 32.9 -1.4674 -2.2 5.9 4U 1735-44 332.4278 -21.8234 3.0 42.4 120.9 2.7713 3.9 ------ UNKNOWN 249.4250 -44.6232 3.0 54.1 21.3 3.9331 3.9 ------ UNKNOWN 6.6332 -29.9270 2.7 35.5 171.3 1.1076 4.2 ------ UNKNOWN 72.6127 -55.7787 4.7 41.0 -98.2 2.0539 2.5 ------ UNKNOWN