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: Sat Jan 20 09:20:59 EST 2018
Host Name: bat1
Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger796469
======================================================================
Trigger: 00796469 Segment: 000
BAT Trigger Time: 534677273.088 [s; MET]
Trigger Stop: 534677274.112 [s; MET]
UTC: 2017-12-11T09:27:32.949900 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 98.108012249038 Dec: -58.669689444389 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 11.03
Image Trigger?: NO
Rate S/N Ratio: 21.0475651798492 [ if not an image trigger ]
Image S/N Ratio: 11.03
Analysis Position: [ source = BAT ]
RA: 98.108012249038 Dec: -58.669689444389 [deg; J2000]
Refined Position: [ source = BAT pre-slew burst ]
RA: 98.1452289806442 Dec: -58.6881597941355 [deg; J2000]
{ 06h 32m 34.9s , -58d 41' 17.4" }
+/- 1.75106632086887 [arcmin] (estimated 90% radius based on SNR)
+/- 0.887388504858632 [arcmin] (formal 1-sigma fit error)
SNR: 13.6629111498022
Angular difference between the analysis and refined position is 1.604864 arcmin
Partial Coding Fraction: 0.578125 [ including projection effects ]
Duration
T90: 2.17600005865097 +/- 0.455367963461657
Measured from: 0.0799999833106995
to: 2.25600004196167 [s; relative to TRIGTIME]
T50: 0.76800000667572 +/- 0.389625496896741
Measured from: 0.38400000333786
to: 1.15200001001358 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 0.0360000133514404
to: 1.03600001335144 [s; relative to TRIGTIME]
Total Fluence
Measured from: 0.0320000052452087
to: 2.63999998569489 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.106308 0.167052 0.100035 0.018681
0.015795 0.016757 0.014705 0.011871 [error]
Peak 0.061975 0.111926 0.072538 0.013629
0.010041 0.011422 0.010216 0.007738 [error]
[ fluence units of on-axis counts / fully illuminated detector ]
======================================================================
====== Table of the duration information =============================
Value tstart tstop
T100 2.608 0.032 2.640
T90 2.176 0.080 2.256
T50 0.768 0.384 1.152
Peak 1.000 0.036 1.036
====== 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 -1.747 -0.208 0.201 - - - 1.00e-02 -1.33e-03 1.30e-03 54.040 57
CPL -1.043 -0.797 1.113 61.072 -17.040 -61.072 2.45e-02 -1.53e-02 7.84e-02 52.120 56
=== 1-s peak spectral analysis ===
(Best model with acceptable fit: N/A)
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 -1.552 -0.199 0.196 - - - 1.79e-02 -2.27e-03 2.25e-03 74.750 57
CPL -0.796 -0.793 1.013 75.283 -22.152 -75.283 4.53e-02 -2.78e-02 1.15e-01 72.130 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 4.21e-08 6.66e-08 7.93e-08 1.84e-07 2.41e-07 3.72e-07 erg/cm2
90%_error_low -7.48e-09 -7.98e-09 -1.38e-08 -5.74e-08 -3.27e-08 -7.24e-08 erg/cm2
90%_error_hi 7.76e-09 7.97e-09 1.38e-08 7.21e-08 3.31e-08 8.36e-08 erg/cm2
Peak flux PL 7.72e-01 7.54e-01 5.14e-01 5.51e-01 2.26e+00 2.59e+00 ph/cm2/s
90%_error_low -1.47e-01 -9.60e-02 -8.08e-02 -1.53e-01 -2.79e-01 -3.19e-01 ph/cm2/s
90%_error_hi 1.54e-01 9.54e-02 8.02e-02 1.84e-01 2.79e-01 3.21e-01 ph/cm2/s
Fluence CPL 3.90e-08 7.26e-08 7.99e-08 6.37e-08 2.27e-07 2.55e-07 erg/cm2
90%_error_low -8.53e-09 -9.96e-09 -1.62e-08 -4.63e-08 -3.72e-08 -6.04e-08 erg/cm2
90%_error_hi 8.65e-09 1.15e-08 1.54e-08 1.41e-07 3.75e-08 1.53e-07 erg/cm2
Peak flux CPL 6.97e-01 8.23e-01 5.41e-01 2.40e-01 2.22e+00 2.30e+00 ph/cm2/s
90%_error_low -1.67e-01 -1.22e-01 -9.17e-02 -1.50e-01 -2.83e-01 -3.25e-01 ph/cm2/s
90%_error_hi 1.72e-01 1.29e-01 9.28e-02 3.46e-01 2.83e-01 3.99e-01 ph/cm2/s
======================================================================
Image
Pre-slew 15.0-350.0 keV image (Event data)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name 98.1452 -58.6882 0.0141 39.5736 -2.2116 0.4073248 13.663 TRIG_00796469 Foreground time interval of the image: 0.032 2.640 (delta_t = 2.608 [sec]) Background time interval of the image: -239.088 0.032 (delta_t = 239.120 [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 0.032 sec. to 2.640 sec. Spectral model in power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.74744 ( -0.208255 0.200938 ) Norm@50keV : 1.00223E-02 ( -0.00132557 0.00130467 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 54.04 using 59 PHA bins. # Reduced chi-squared = 0.9481 for 57 degrees of freedom # Null hypothesis probability = 5.867262e-01 Photon flux (15-150 keV) in 2.608 sec: 1.35397 ( -0.16329 0.16345 ) ph/cm2/s Energy fluence (15-150 keV) : 2.41261e-07 ( -3.26887e-08 3.30966e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.032 sec. to 2.640 sec. Spectral model in the cutoff power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.0428 ( -0.79733 1.11293 ) Epeak [keV] : 61.0718 ( -17.0392 -61.0712 ) Norm@50keV : 2.45209E-02 ( -0.0153326 0.0783989 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 52.12 using 59 PHA bins. # Reduced chi-squared = 0.9307 for 56 degrees of freedom # Null hypothesis probability = 6.226159e-01 Photon flux (15-150 keV) in 2.608 sec: 1.32288 ( -0.16861 0.16814 ) ph/cm2/s Energy fluence (15-150 keV) : 2.27226e-07 ( -3.7237e-08 3.74522e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 0.036 sec. to 1.036 sec. Spectral model in power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.55197 ( -0.199384 0.195765 ) Norm@50keV : 1.78537E-02 ( -0.00226748 0.0022499 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 74.75 using 59 PHA bins. # Reduced chi-squared = 1.311 for 57 degrees of freedom # Null hypothesis probability = 5.738340e-02 Photon flux (15-150 keV) in 1 sec: 2.26154 ( -0.27859 0.27887 ) ph/cm2/s Energy fluence (15-150 keV) : 1.68051e-07 ( -2.28666e-08 2.30927e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.036 sec. to 1.036 sec. Spectral model in the cutoff power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -0.795935 ( -0.793333 1.01312 ) Epeak [keV] : 75.2830 ( -22.1524 -75.2834 ) Norm@50keV : 4.52688E-02 ( -0.0277997 0.114592 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 72.13 using 59 PHA bins. # Reduced chi-squared = 1.288 for 56 degrees of freedom # Null hypothesis probability = 7.218848e-02 Photon flux (15-150 keV) in 1 sec: 2.21705 ( -0.28313 0.28311 ) ph/cm2/s Energy fluence (15-150 keV) : 1.59071e-07 ( -2.54884e-08 2.52862e-08 ) ergs/cm2
Time-resolved spectra
Distribution
T90 vs. Hardness ratio plot
T90 = 2.176 sec. Hardness ratio (energy fluence ratio) = 1.19135149978
S(15-50 keV) vs. S(50-150 keV) plot
S(15-50 keV) = 1.0869383e-07 S(50-150 keV) = 1.3256519e-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 = 8.258796853203473E-01, IMY = 3.189422191671311E-02
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: -239.088000 0.032000 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 135.6431 -40.4459 3.2 10.4 -18.8 0.8357 3.6 8.4 Vela X-1 170.3663 -60.5596 262.3 36.4 -60.0 0.0206 0.0 4.1 Cen X-3 156.9738 6.3927 2.7 40.6 172.8 1.7327 4.3 ------ UNKNOWN 66.3645 -64.9835 3.4 55.5 -5.3 2.6847 3.4 ------ UNKNOWN 178.3628 -19.3475 3.0 36.9 -133.1 1.4442 3.9 ------ UNKNOWN 55.4301 -81.0907 4.4 58.9 -24.4 4.4290 2.6 ------ UNKNOWN 160.7376 -80.4555 3.0 50.7 -39.2 3.8316 3.8 ------ UNKNOWN
Pre-slew background subtracted image of 15-350 keV band
Time interval of the image: 0.032000 2.640000 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 135.2809 -40.5579 12.0 10.6 -17.6 0.0190 1.0 11.3 Vela X-1 170.1234 -60.6865 13.3 36.4 -59.7 0.0336 0.9 6.8 Cen X-3 163.7685 17.1835 2.3 53.2 174.8 0.3951 4.9 ------ UNKNOWN 98.1452 -58.6882 0.8 39.6 -2.2 0.4108 13.8 ------ UNKNOWN
Post-slew image of 15-350 keV band
Time interval of the image: 76.012600 963.022000 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 135.4983 -40.5397 1.6 29.7 177.1 4.0406 7.0 1.6 Vela X-1 170.0188 -60.7266 0.0 34.5 -127.0 -0.9402 -1.0 10.7 Cen X-3 186.6134 -62.7451 3.9 40.0 -117.2 4.4931 3.0 1.9 GX 301-2 49.1435 -24.0043 3.0 48.7 41.8 8.6229 3.9 ------ UNKNOWN 37.4178 -42.7367 2.9 39.9 14.1 3.0818 4.0 ------ UNKNOWN 159.1368 -21.5479 2.3 56.8 -175.2 12.8193 4.9 ------ UNKNOWN 6.9734 -59.6162 3.5 43.0 -23.9 2.8882 3.3 ------ UNKNOWN 311.4731 -75.1433 2.8 44.4 -60.2 11.5840 4.1 ------ UNKNOWN 287.2363 -78.6973 2.3 42.5 -69.2 12.1680 5.1 ------ UNKNOWN