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: Sun Mar 17 22:41:43 EDT 2019
Host Name: bat1
Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger885314
======================================================================
Trigger: 00885314 Segment: 000
BAT Trigger Time: 569938775.488 [s; MET]
Trigger Stop: 569938783.68 [s; MET]
UTC: 2019-01-23T12:19:13.191160 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 53.2292503021484 Dec: 45.4840092707705 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 11.49
Image Trigger?: NO
Rate S/N Ratio: 16.5529453572468 [ if not an image trigger ]
Image S/N Ratio: 11.49
Analysis Position: [ source = BAT ]
RA: 53.2292503021484 Dec: 45.4840092707705 [deg; J2000]
Refined Position: [ source = BAT pre-slew burst ]
RA: 53.1781384919464 Dec: 45.5038450127407 [deg; J2000]
{ 03h 32m 42.8s , +45d 30' 13.8" }
+/- 1.73917822028068 [arcmin] (estimated 90% radius based on SNR)
+/- 0.802654670846529 [arcmin] (formal 1-sigma fit error)
SNR: 13.7965240610847
Angular difference between the analysis and refined position is 2.457178 arcmin
Partial Coding Fraction: 0.6484375 [ including projection effects ]
Duration
T90: 25.12399995327 +/- 4.06866118463902
Measured from: -0.340000033378601
to: 24.7839999198914 [s; relative to TRIGTIME]
T50: 11.432000041008 +/- 5.61054178216102
Measured from: 3.13599991798401
to: 14.567999958992 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 4.8199999332428
to: 5.8199999332428 [s; relative to TRIGTIME]
Total Fluence
Measured from: -1.22000002861023
to: 27.6480000019073 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.297741 0.289965 0.426653 0.170422
0.044572 0.046733 0.041814 0.037492 [error]
Peak 0.026388 0.029333 0.046083 0.022404
0.008875 0.009544 0.008614 0.007756 [error]
[ fluence units of on-axis counts / fully illuminated detector ]
======================================================================
====== Table of the duration information =============================
Value tstart tstop
T100 28.868 -1.220 27.648
T90 25.124 -0.340 24.784
T50 11.432 3.136 14.568
Peak 1.000 4.820 5.820
====== 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 -1.105 -0.222 0.228 - - - 2.82e-03 -3.39e-04 3.37e-04 67.390 57
CPL -1.047 -0.280 0.662 978.755 -978.755 -978.755 2.99e-03 -4.87e-04 1.83e-04 67.520 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 -1.033 -0.398 0.432 - - - 8.59e-03 -1.94e-03 1.90e-03 70.060 57
CPL -1.037 -0.390 0.447 9999.360 -9999.360 -9999.360 8.64e-03 -1.90e-03 8.86e-02 70.060 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 6.99e-08 1.64e-07 3.05e-07 1.36e-06 8.26e-07 1.90e-06 erg/cm2
90%_error_low -1.72e-08 -2.47e-08 -4.12e-08 -3.90e-07 -1.05e-07 -4.14e-07 erg/cm2
90%_error_hi 1.87e-08 2.41e-08 4.05e-08 4.94e-07 1.06e-07 5.03e-07 erg/cm2
Peak flux PL 2.26e-01 3.01e-01 2.94e-01 5.15e-01 9.91e-01 1.34e+00 ph/cm2/s
90%_error_low -1.00e-01 -8.93e-02 -6.92e-02 -2.26e-01 -2.27e-01 -3.03e-01 ph/cm2/s
90%_error_hi 1.19e-01 8.57e-02 6.77e-02 3.28e-01 2.29e-01 3.20e-01 ph/cm2/s
Fluence CPL 6.99e-08 1.64e-07 3.05e-07 1.35e-06 8.26e-07 1.91e-06 erg/cm2
90%_error_low N/A N/A N/A N/A N/A -7.77e-07 erg/cm2
90%_error_hi N/A N/A N/A N/A N/A 2.05e-07 erg/cm2
Peak flux CPL 2.26e-01 3.00e-01 2.94e-01 5.12e-01 9.94e-01 1.41e+00 ph/cm2/s
90%_error_low N/A N/A N/A N/A N/A -6.13e-01 ph/cm2/s
90%_error_hi N/A N/A N/A N/A N/A 2.22e-01 ph/cm2/s
======================================================================
Image
Pre-slew 15.0-350.0 keV image (Event data)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name 53.1781 45.5038 0.0139 32.2354 -145.9780 1.2520171 13.797 TRIG_00885314 Foreground time interval of the image: -1.220 9.693 (delta_t = 10.913 [sec]) 10.512 27.648 (delta_t = 17.136 [sec]) Background time interval of the image: -239.488 -1.220 (delta_t = 238.268 [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
Multiple GTIs in the spectrum tstart tstop -1.220000 9.692800 10.512000 27.648000 Spectral model in power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.10513 ( -0.221544 0.228256 ) Norm@50keV : 2.82237E-03 ( -0.000338988 0.000337253 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 67.39 using 59 PHA bins. # Reduced chi-squared = 1.182 for 57 degrees of freedom # Null hypothesis probability = 1.632208e-01 Photon flux (15-150 keV) in 28.05 sec: 0.327541 ( -0.041039 0.041221 ) ph/cm2/s Energy fluence (15-150 keV) : 8.26462e-07 ( -1.05251e-07 1.05724e-07 ) ergs/cm2
Cutoff power-law model
Multiple GTIs in the spectrum tstart tstop -1.220000 9.692800 10.512000 27.648000 Spectral model in the cutoff power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.09976 ( -0.279882 0.662126 ) Epeak [keV] : 1.00000E+04 ( -10000 -10000 ) Norm@50keV : 2.83720E-03 ( -0.000335495 0.00033419 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 67.40 using 59 PHA bins. # Reduced chi-squared = 1.204 for 56 degrees of freedom # Null hypothesis probability = 1.414137e-01 Photon flux (15-150 keV) in 28.05 sec: 0.327491 ( ) ph/cm2/s Energy fluence (15-150 keV) : 8.26232e-07 ( 0 0 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 4.820 sec. to 5.820 sec. Spectral model in power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.03264 ( -0.397828 0.4321 ) Norm@50keV : 8.58752E-03 ( -0.00193645 0.00189989 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 70.06 using 59 PHA bins. # Reduced chi-squared = 1.229 for 57 degrees of freedom # Null hypothesis probability = 1.147281e-01 Photon flux (15-150 keV) in 1 sec: 0.990598 ( -0.227207 0.229162 ) ph/cm2/s Energy fluence (15-150 keV) : 9.18206e-08 ( -2.11596e-08 2.131e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 4.820 sec. to 5.820 sec. Spectral model in the cutoff power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.03746 ( -0.39381 0.443417 ) Epeak [keV] : 9999.36 ( -9999.36 -9999.36 ) Norm@50keV : 8.63779E-03 ( -0.00189561 0.0886436 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 70.06 using 59 PHA bins. # Reduced chi-squared = 1.251 for 56 degrees of freedom # Null hypothesis probability = 9.795309e-02 Photon flux (15-150 keV) in 1 sec: 0.994170 ( ) ph/cm2/s Energy fluence (15-150 keV) : 9.20556e-08 ( -2.28916e-08 2.15527e-08 ) ergs/cm2
Time-resolved spectra
Distribution
T90 vs. Hardness ratio plot
T90 = 25.124 sec. Hardness ratio (energy fluence ratio) = 1.85951527896
S(15-50 keV) vs. S(50-150 keV) plot
S(15-50 keV) = 2.3370263e-07 S(50-150 keV) = 5.927521e-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 = -5.226531001837519E-01, IMY = 3.528256816859616E-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: -239.488000 -1.220000 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 83.6475 21.9908 0.6 40.9 156.5 11.1228 18.4 1.6 Crab 181.4623 36.4153 3.7 53.6 28.2 4.7584 3.2 ------ UNKNOWN 178.1023 43.5447 2.2 46.5 25.0 2.8736 5.2 ------ UNKNOWN 170.1979 55.2734 3.0 34.7 17.3 1.2708 3.8 ------ UNKNOWN 212.8069 54.8316 2.4 52.1 -7.4 2.7019 4.8 ------ UNKNOWN 40.8546 61.4472 1.1 28.7 -111.8 3.8489 10.1 ------ UNKNOWN 38.9306 23.5383 2.5 56.7 -151.7 6.3624 4.5 ------ UNKNOWN 288.3833 72.2319 3.0 47.0 -53.1 4.8549 3.9 ------ UNKNOWN
Pre-slew background subtracted image of 15-350 keV band
Time interval of the image: -1.220000 9.692800 10.512000 27.648000 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 83.6314 22.1866 0.0 40.7 156.6 0.2322 1.5 10.3 Crab 203.2849 46.3102 2.4 55.5 4.8 1.2184 4.8 ------ UNKNOWN 53.1781 45.5039 0.8 32.2 -146.0 1.2520 13.8 ------ UNKNOWN 256.8515 71.1147 2.2 47.0 -39.6 0.9262 5.2 ------ UNKNOWN
Post-slew image of 15-350 keV band
Time interval of the image: 103.612600 250.412600 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 83.6246 22.0089 0.8 34.1 125.3 5.7059 14.2 0.6 Crab 67.6785 -8.5435 2.3 55.6 164.6 5.8810 5.1 ------ UNKNOWN 248.8052 82.8651 2.5 51.4 -0.4 1.7548 4.6 ------ UNKNOWN 40.9104 61.4380 0.8 17.5 -17.9 2.5281 13.9 ------ UNKNOWN