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 May 31 13:31:31 EDT 2018
Host Name: bat1
Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger830822
======================================================================
Trigger: 00830822 Segment: 000
BAT Trigger Time: 547155994.176 [s; MET]
Trigger Stop: 547156002.368 [s; MET]
UTC: 2018-05-04T19:46:13.285300 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 331.133622917772 Dec: -14.6549190111758 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 11.05
Image Trigger?: NO
Rate S/N Ratio: 14.2828568570857 [ if not an image trigger ]
Image S/N Ratio: 11.05
Analysis Position: [ source = BAT ]
RA: 331.133622917772 Dec: -14.6549190111758 [deg; J2000]
Refined Position: [ source = BAT pre-slew burst ]
RA: 331.142793776535 Dec: -14.6665990703257 [deg; J2000]
{ 22h 04m 34.3s , -14d 39' 59.8" }
+/- 1.36795960521522 [arcmin] (estimated 90% radius based on SNR)
+/- 0.474976387765398 [arcmin] (formal 1-sigma fit error)
SNR: 19.4414203187425
Angular difference between the analysis and refined position is 0.880061 arcmin
Partial Coding Fraction: 0.6171875 [ including projection effects ]
Duration
T90: 115.263999819756 +/- 48.6950530255852
Measured from: -27.9119999408722
to: 87.3519998788834 [s; relative to TRIGTIME]
T50: 24.8319998979568 +/- 5.46741332173305
Measured from: -1.22399997711182
to: 23.607999920845 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 16.8040000200272
to: 17.8040000200272 [s; relative to TRIGTIME]
Total Fluence
Measured from: -44.2960000038147
to: 133.68799996376 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 1.116108 1.355610 1.038132 0.222276
0.092696 0.095986 0.085813 0.076871 [error]
Peak 0.031184 0.038259 0.030130 0.017936
0.008011 0.008147 0.007326 0.006461 [error]
[ fluence units of on-axis counts / fully illuminated detector ]
======================================================================
====== Table of the duration information =============================
Value tstart tstop
T100 177.984 -44.296 133.688
T90 115.264 -27.912 87.352
T50 24.832 -1.224 23.608
Peak 1.000 16.804 17.804
====== 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 -1.489 -0.142 0.141 - - - 1.39e-03 -1.08e-04 1.07e-04 61.300 57
CPL -1.489 -0.140 0.144 9999.220 -9999.220 -9999.220 1.39e-03 -1.39e-03 7.97e-04 61.310 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 -1.508 -0.443 0.435 - - - 6.67e-03 -1.65e-03 1.59e-03 57.790 57
CPL -1.520 -0.432 1.008 9999.340 -9999.340 -9999.340 6.66e-03 -1.64e-03 1.60e-02 57.790 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 3.12e-07 5.77e-07 8.22e-07 2.47e-06 2.35e-06 4.18e-06 erg/cm2
90%_error_low -4.11e-08 -4.58e-08 -8.56e-08 -5.20e-07 -2.02e-07 -5.90e-07 erg/cm2
90%_error_hi 4.26e-08 4.55e-08 8.51e-08 6.10e-07 2.05e-07 6.64e-07 erg/cm2
Peak flux PL 2.77e-01 2.77e-01 1.95e-01 2.17e-01 8.34e-01 9.66e-01 ph/cm2/s
90%_error_low -1.04e-01 -6.67e-02 -6.24e-02 -1.15e-01 -1.90e-01 -2.26e-01 ph/cm2/s
90%_error_hi 1.13e-01 6.52e-02 6.12e-02 1.79e-01 1.91e-01 2.32e-01 ph/cm2/s
Fluence CPL 3.14e-07 5.70e-07 8.17e-07 2.56e-06 2.37e-06 4.06e-06 erg/cm2
90%_error_low -4.88e-08 -4.20e-08 N/A -1.26e-06 -2.30e-07 -1.08e-06 erg/cm2
90%_error_hi 4.40e-08 6.07e-08 N/A 2.16e-07 1.79e-07 7.61e-07 erg/cm2
Peak flux CPL 2.86e-01 2.70e-01 1.92e-01 2.16e-01 8.36e-01 1.01e+00 ph/cm2/s
90%_error_low N/A -7.69e-02 -1.50e-01 N/A -1.94e-01 -3.53e-01 ph/cm2/s
90%_error_hi N/A 9.22e-02 -6.15e-02 N/A 1.90e-01 2.32e-01 ph/cm2/s
======================================================================
Image
Pre-slew 15.0-350.0 keV image (Event data)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name 331.1428 -14.6666 0.0099 23.6561 74.6441 3.4971150 19.441 TRIG_00830822 Foreground time interval of the image: -44.296 52.125 (delta_t = 96.421 [sec]) Background time interval of the image: -220.075 -44.296 (delta_t = 175.779 [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 -44.296 sec. to 133.688 sec. Spectral model in power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.48944 ( -0.141752 0.140513 ) Norm@50keV : 1.38660E-03 ( -0.000107983 0.000107372 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 61.30 using 59 PHA bins. # Reduced chi-squared = 1.075 for 57 degrees of freedom # Null hypothesis probability = 3.244203e-01 Photon flux (15-150 keV) in 178 sec: 0.172619 ( -0.013247 0.013271 ) ph/cm2/s Energy fluence (15-150 keV) : 2.34579e-06 ( -2.02455e-07 2.0462e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -44.296 sec. to 133.688 sec. Spectral model in the cutoff power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.48939 ( -0.139892 0.14357 ) Epeak [keV] : 9999.22 ( -9999.36 -9999.36 ) Norm@50keV : 1.38881E-03 ( -0.00139033 0.000795429 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 61.31 using 59 PHA bins. # Reduced chi-squared = 1.095 for 56 degrees of freedom # Null hypothesis probability = 2.913244e-01 Photon flux (15-150 keV) in 178 sec: 0.173705 ( ) ph/cm2/s Energy fluence (15-150 keV) : 2.36793e-06 ( -2.30168e-07 1.79307e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 16.804 sec. to 17.804 sec. Spectral model in power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.50832 ( -0.442896 0.435065 ) Norm@50keV : 6.66721E-03 ( -0.00165302 0.0015933 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 57.79 using 59 PHA bins. # Reduced chi-squared = 1.014 for 57 degrees of freedom # Null hypothesis probability = 4.460446e-01 Photon flux (15-150 keV) in 1 sec: 0.834226 ( -0.190348 0.190624 ) ph/cm2/s Energy fluence (15-150 keV) : 6.31713e-08 ( -1.6947e-08 1.74667e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 16.804 sec. to 17.804 sec. Spectral model in the cutoff power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.52007 ( -0.432987 1.00746 ) Epeak [keV] : 9999.34 ( -9999.36 -9999.36 ) Norm@50keV : 6.66440E-03 ( -0.00164834 0.0159544 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 57.79 using 59 PHA bins. # Reduced chi-squared = 1.032 for 56 degrees of freedom # Null hypothesis probability = 4.088281e-01 Photon flux (15-150 keV) in 1 sec: 0.836233 ( -0.194451 0.190297 ) ph/cm2/s Energy fluence (15-150 keV) : 3.25904e-08 ( 0 0 ) ergs/cm2
Time-resolved spectra
Distribution
T90 vs. Hardness ratio plot
T90 = 115.264 sec. Hardness ratio (energy fluence ratio) = 1.42465619313
S(15-50 keV) vs. S(50-150 keV) plot
S(15-50 keV) = 8.891659e-07 S(50-150 keV) = 1.4566251e-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 = 1.160035673997685E-01, IMY = -4.224173148142144E-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: -220.075400 -44.296000 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 308.1078 40.9258 16.7 55.4 166.8 0.6994 0.7 1.6 Cyg X-3 326.1568 38.1342 0.0 43.7 177.3 0.8332 2.3 11.3 Cyg X-2 342.9932 17.0357 3.1 18.1 -176.8 0.6328 3.6 ------ UNKNOWN 15.0478 19.5156 3.5 31.4 -105.0 1.0431 3.3 ------ UNKNOWN 16.2237 41.8213 2.6 48.0 -129.0 3.9798 4.5 ------ UNKNOWN
Pre-slew background subtracted image of 15-350 keV band
Time interval of the image: -44.296000 52.124600 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 308.0439 40.8624 4.3 55.5 166.7 -2.0448 -2.7 6.2 Cyg X-3 326.2428 38.4372 12.2 43.9 177.6 0.2401 1.0 7.7 Cyg X-2 319.7030 2.3227 2.4 30.1 118.7 1.0191 4.7 ------ UNKNOWN 331.1428 -14.6666 0.6 23.7 74.6 3.4971 19.5 ------ UNKNOWN 18.5058 -26.7269 2.4 38.6 -19.1 0.9326 4.9 ------ UNKNOWN
Post-slew image of 15-350 keV band
Time interval of the image: 97.124600 719.454800 720.824000 962.944000 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 288.8408 10.9666 4.1 49.1 140.3 8.7765 2.8 2.8 GRS 1915+105 326.3249 38.2971 7.4 53.1 -163.5 3.0522 1.6 7.4 Cyg X-2 288.6205 -19.4607 4.4 40.8 98.3 6.6147 2.6 ------ UNKNOWN 288.9193 -16.5719 2.6 40.6 102.7 10.4037 4.4 ------ UNKNOWN 303.5025 -39.4834 3.7 34.7 60.2 3.2807 3.1 ------ UNKNOWN 341.5859 -69.7894 3.3 55.5 16.9 10.6694 3.5 ------ UNKNOWN 351.4508 -62.4560 2.9 49.9 9.1 5.2569 4.0 ------ UNKNOWN 343.6970 33.9262 3.7 50.0 -145.2 7.1421 3.1 ------ UNKNOWN 355.5322 27.1159 3.8 48.0 -129.2 9.4685 3.1 ------ UNKNOWN