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 10:32:58 EST 2018
Host Name: bat1
Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger783479
======================================================================
Trigger: 00783479 Segment: 000
BAT Trigger Time: 530785406.528 [s; MET]
Trigger Stop: 530785410.624 [s; MET]
UTC: 2017-10-27T08:23:06.622860 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 61.6803931109227 Dec: -2.60607661453514 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 10.64
Image Trigger?: NO
Rate S/N Ratio: 19.4164878389476 [ if not an image trigger ]
Image S/N Ratio: 10.64
Analysis Position: [ source = BAT ]
RA: 61.6803931109227 Dec: -2.60607661453514 [deg; J2000]
Refined Position: [ source = BAT pre-slew burst ]
RA: 61.682508830707 Dec: -2.60030518316982 [deg; J2000]
{ 04h 06m 43.8s , -02d 36' 01.1" }
+/- 1.10010075033232 [arcmin] (estimated 90% radius based on SNR)
+/- 0.551651207375305 [arcmin] (formal 1-sigma fit error)
SNR: 26.5417253068916
Angular difference between the analysis and refined position is 0.368775 arcmin
Partial Coding Fraction: 0.9140625 [ including projection effects ]
Duration
T90: 96.7719999551773 +/- 4.9069697352188
Measured from: 7.67199999094009
to: 104.443999946117 [s; relative to TRIGTIME]
T50: 29.567999958992 +/- 1.31383402806664
Measured from: 44.1280000209808
to: 73.6959999799728 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 62.2639999985695
to: 63.2639999985695 [s; relative to TRIGTIME]
Total Fluence
Measured from: -1.09600001573563
to: 129.98400002718 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 3.313078 4.698913 3.638017 0.875773
0.071947 0.076349 0.067335 0.055179 [error]
Peak 0.083522 0.150750 0.134317 0.028664
0.007113 0.008270 0.007422 0.005382 [error]
[ fluence units of on-axis counts / fully illuminated detector ]
======================================================================
====== Table of the duration information =============================
Value tstart tstop
T100 131.080 -1.096 129.984
T90 96.772 7.672 104.444
T50 29.568 44.128 73.696
Peak 1.000 62.264 63.264
====== 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 -1.459 -0.042 0.042 - - - 6.19e-03 -1.34e-04 1.34e-04 56.860 57
CPL -1.301 -0.085 0.169 248.618 -99.246 -248.618 7.27e-03 -9.79e-04 1.34e-03 54.150 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 -1.176 -0.098 0.099 - - - 2.59e-02 -1.53e-03 1.53e-03 41.890 57
CPL -0.507 -0.424 0.471 120.229 -29.091 108.758 5.39e-02 -1.96e-02 3.46e-02 34.280 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 9.96e-07 1.88e-06 2.73e-06 8.47e-06 7.75e-06 1.41e-05 erg/cm2
90%_error_low -4.53e-08 -4.91e-08 -7.17e-08 -5.13e-07 -1.76e-07 -5.46e-07 erg/cm2
90%_error_hi 4.61e-08 4.90e-08 7.15e-08 5.36e-07 1.76e-07 5.64e-07 erg/cm2
Peak flux PL 7.82e-01 9.55e-01 8.45e-01 1.29e+00 3.03e+00 3.87e+00 ph/cm2/s
90%_error_low -8.49e-02 -6.55e-02 -5.76e-02 -1.74e-01 -1.83e-01 -2.43e-01 ph/cm2/s
90%_error_hi 8.79e-02 6.50e-02 5.73e-02 1.90e-01 1.83e-01 2.46e-01 ph/cm2/s
Fluence CPL 9.56e-07 1.89e-06 2.77e-06 6.88e-06 7.66e-06 1.25e-05 erg/cm2
90%_error_low -5.99e-08 -5.14e-08 -8.06e-08 -1.30e-06 -1.96e-07 -1.30e-06 erg/cm2
90%_error_hi 6.11e-08 5.16e-08 8.12e-08 1.58e-06 1.95e-07 1.53e-06 erg/cm2
Peak flux CPL 6.76e-01 1.01e+00 9.07e-01 6.72e-01 2.96e+00 3.26e+00 ph/cm2/s
90%_error_low -1.05e-01 -7.52e-02 -7.01e-02 -2.11e-01 -1.89e-01 -2.87e-01 ph/cm2/s
90%_error_hi 1.08e-01 7.64e-02 7.13e-02 3.28e-01 1.89e-01 3.63e-01 ph/cm2/s
======================================================================
Image
Pre-slew 15.0-350.0 keV image (Event data)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name 61.6825 -2.6003 0.0073 17.7237 37.5020 2.1965366 26.542 TRIG_00783479 Foreground time interval of the image: -1.096 37.573 (delta_t = 38.669 [sec]) Background time interval of the image: -254.627 -1.096 (delta_t = 253.531 [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 -1.096 sec. to 129.984 sec. Spectral model in power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.45896 ( -0.0422959 0.0423226 ) Norm@50keV : 6.18550E-03 ( -0.000134139 0.000134134 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 56.86 using 59 PHA bins. # Reduced chi-squared = 0.9976 for 57 degrees of freedom # Null hypothesis probability = 4.801383e-01 Photon flux (15-150 keV) in 131.1 sec: 0.764003 ( -0.018701 0.018762 ) ph/cm2/s Energy fluence (15-150 keV) : 7.74823e-06 ( -1.75848e-07 1.761e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -1.096 sec. to 129.984 sec. Spectral model in the cutoff power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.30101 ( -0.0846607 0.169422 ) Epeak [keV] : 248.618 ( -99.2454 -248.618 ) Norm@50keV : 7.27436E-03 ( -0.00097881 0.00133965 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 54.15 using 59 PHA bins. # Reduced chi-squared = 0.9669 for 56 degrees of freedom # Null hypothesis probability = 5.453597e-01 Photon flux (15-150 keV) in 131.1 sec: 0.754139 ( -0.021063 0.021158 ) ph/cm2/s Energy fluence (15-150 keV) : 7.66466e-06 ( -1.95997e-07 1.95346e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 62.264 sec. to 63.264 sec. Spectral model in power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.1758 ( -0.098407 0.098982 ) Norm@50keV : 2.59003E-02 ( -0.0015287 0.0015287 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 41.89 using 59 PHA bins. # Reduced chi-squared = 0.7350 for 57 degrees of freedom # Null hypothesis probability = 9.331281e-01 Photon flux (15-150 keV) in 1 sec: 3.03022 ( -0.18273 0.18288 ) ph/cm2/s Energy fluence (15-150 keV) : 2.64631e-07 ( -1.73561e-08 1.74345e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 62.264 sec. to 63.264 sec. Spectral model in the cutoff power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -0.506636 ( -0.424246 0.470522 ) Epeak [keV] : 120.229 ( -29.091 108.757 ) Norm@50keV : 5.38758E-02 ( -0.0196049 0.0346464 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 34.28 using 59 PHA bins. # Reduced chi-squared = 0.6122 for 56 degrees of freedom # Null hypothesis probability = 9.902392e-01 Photon flux (15-150 keV) in 1 sec: 2.95890 ( -0.18893 0.18851 ) ph/cm2/s Energy fluence (15-150 keV) : 2.54812e-07 ( -1.87914e-08 1.87464e-08 ) ergs/cm2
Time-resolved spectra
Distribution
T90 vs. Hardness ratio plot
T90 = 96.772 sec. Hardness ratio (energy fluence ratio) = 1.45505732586
S(15-50 keV) vs. S(50-150 keV) plot
S(15-50 keV) = 2.8738226e-06 S(50-150 keV) = 4.874419e-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 = 2.535455495875235E-01, IMY = -1.945664264299750E-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: -254.627410 -1.096000 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 83.6228 22.0181 0.3 17.4 174.9 10.3038 43.6 0.6 Crab 61.6568 0.9257 2.7 16.4 48.6 1.1159 4.3 ------ UNKNOWN 105.8944 37.6068 2.3 41.1 -169.8 1.9158 4.9 ------ UNKNOWN
Pre-slew background subtracted image of 15-350 keV band
Time interval of the image: -1.096000 37.572600 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 83.4838 22.0578 21.3 17.4 174.4 0.0406 0.5 8.7 Crab 35.8652 7.9023 2.0 41.2 70.6 1.8266 5.7 ------ UNKNOWN 35.7261 2.9221 1.7 41.6 63.0 1.9527 6.8 ------ UNKNOWN 38.6004 -36.7457 2.1 55.8 12.4 2.5068 5.5 ------ UNKNOWN 61.6825 -2.6004 0.4 17.7 37.5 2.1966 26.5 ------ UNKNOWN 62.3081 -48.3345 2.0 55.6 -12.9 1.5611 5.7 ------ UNKNOWN
Post-slew image of 15-350 keV band
Time interval of the image: 76.572590 962.531700 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 83.6155 22.0231 0.2 32.7 -168.2 30.2487 52.2 1.1 Crab 27.3476 20.3242 2.4 40.7 97.7 9.5653 4.9 ------ UNKNOWN 61.1391 46.3811 2.9 49.0 151.4 8.2866 4.0 ------ UNKNOWN 61.6526 -2.6051 1.5 0.0 82.5 4.0119 7.9 ------ UNKNOWN 78.1239 -3.2216 3.3 16.4 -115.6 1.9024 3.5 ------ UNKNOWN 112.0216 27.9501 3.0 57.2 -154.1 14.5080 3.9 ------ UNKNOWN 100.6154 -12.6706 4.2 39.8 -101.4 6.7954 2.8 ------ UNKNOWN