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 22:27:41 EDT 2019
Host Name: bat1
Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger888648
======================================================================
Trigger: 00888648 Segment: 000
BAT Trigger Time: 571596907.136 [s; MET]
Trigger Stop: 571596909.184 [s; MET]
UTC: 2019-02-11T16:54:44.735040 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 196.67538854469 Dec: 41.9660247246067 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 6.93
Image Trigger?: NO
Rate S/N Ratio: 9.16515138991168 [ if not an image trigger ]
Image S/N Ratio: 6.93
Analysis Position: [ source = BAT ]
RA: 196.67538854469 Dec: 41.9660247246067 [deg; J2000]
Refined Position: [ source = BAT pre-slew burst ]
RA: 196.651839434863 Dec: 41.9686001671772 [deg; J2000]
{ 13h 06m 36.4s , +41d 58' 07.0" }
+/- 2.4082520685682 [arcmin] (estimated 90% radius based on SNR)
+/- 1.12611541339411 [arcmin] (formal 1-sigma fit error)
SNR: 8.66622362410689
Angular difference between the analysis and refined position is 1.061867 arcmin
Partial Coding Fraction: 0.2617188 [ including projection effects ]
Duration
T90: 10.8960000276566 +/- 1.54339884541641
Measured from: -9.44000005722046
to: 1.4559999704361 [s; relative to TRIGTIME]
T50: 7.27999997138977 +/- 3.10916066829362
Measured from: -6.5440000295639
to: 0.735999941825867 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 0.564000010490417
to: 1.56400001049042 [s; relative to TRIGTIME]
Total Fluence
Measured from: -9.75999999046326
to: 1.66399991512299 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.202334 0.282970 0.231516 0.139260
0.049711 0.050967 0.045443 0.040626 [error]
Peak 0.070087 0.059704 0.085217 0.020614
0.015647 0.017049 0.015913 0.012892 [error]
[ fluence units of on-axis counts / fully illuminated detector ]
======================================================================
====== Table of the duration information =============================
Value tstart tstop
T100 11.424 -9.760 1.664
T90 10.896 -9.440 1.456
T50 7.280 -6.544 0.736
Peak 1.000 0.564 1.564
====== 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 -1.317 -0.368 0.380 - - - 5.15e-03 -9.19e-04 9.19e-04 64.210 57
CPL -1.328 -2.527 -0.607 9999.360 N/A N/A 5.17e-03 N/A N/A 64.230 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 -1.182 -0.438 0.456 - - - 1.62e-02 -3.51e-03 3.44e-03 54.520 57
CPL -1.224 -0.399 0.510 9999.360 -9999.360 -9999.360 1.61e-02 -3.27e-03 -1.61e-02 54.580 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 6.33e-08 1.30e-07 2.09e-07 7.50e-07 5.79e-07 1.15e-06 erg/cm2
90%_error_low -2.32e-08 -2.93e-08 -4.72e-08 -3.34e-07 -1.13e-07 -3.65e-07 erg/cm2
90%_error_hi 2.60e-08 2.75e-08 4.50e-08 4.93e-07 1.13e-07 4.99e-07 erg/cm2
Peak flux PL 4.92e-01 5.98e-01 5.27e-01 7.99e-01 1.90e+00 2.42e+00 ph/cm2/s
90%_error_low -2.22e-01 -1.78e-01 -1.29e-01 -3.77e-01 -4.38e-01 -5.19e-01 ph/cm2/s
90%_error_hi 2.64e-01 1.64e-01 1.21e-01 5.39e-01 4.38e-01 5.30e-01 ph/cm2/s
Fluence CPL 4.93e-08 1.30e-07 1.94e-07 7.76e-07 2.19e-07 1.12e-06 erg/cm2
90%_error_low N/A -3.11e-08 -3.28e-08 -4.63e-07 N/A -3.81e-07 erg/cm2
90%_error_hi N/A 2.87e-08 5.96e-08 5.90e-07 N/A 5.22e-07 erg/cm2
Peak flux CPL 4.92e-01 6.04e-01 5.26e-01 8.16e-01 1.90e+00 2.38e+00 ph/cm2/s
90%_error_low N/A -1.93e-01 N/A N/A -4.41e-01 -4.81e-01 ph/cm2/s
90%_error_hi N/A 1.66e-01 N/A N/A 4.36e-01 5.50e-01 ph/cm2/s
======================================================================
Image
Pre-slew 15.0-350.0 keV image (Event data)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name 196.6518 41.9686 0.0222 42.0614 -132.2798 0.9446369 8.666 TRIG_00888648 Foreground time interval of the image: -9.760 1.664 (delta_t = 11.424 [sec]) Background time interval of the image: -157.635 -9.760 (delta_t = 147.875 [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 -9.760 sec. to 1.664 sec. Spectral model in power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.31699 ( -0.367829 0.380114 ) Norm@50keV : 5.15187E-03 ( -0.000919366 0.000919191 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 64.21 using 59 PHA bins. # Reduced chi-squared = 1.126 for 57 degrees of freedom # Null hypothesis probability = 2.387345e-01 Photon flux (15-150 keV) in 11.42 sec: 0.616585 ( -0.119643 0.120003 ) ph/cm2/s Energy fluence (15-150 keV) : 5.79104e-07 ( -1.12738e-07 1.13056e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -9.760 sec. to 1.664 sec. Spectral model in the cutoff power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -2.58759 ( -1.266 0.654064 ) Epeak [keV] : 191.353 ( ) Norm@50keV : 1.14735E-03 ( ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 61.69 using 59 PHA bins. # Reduced chi-squared = 1.102 for 56 degrees of freedom # Null hypothesis probability = 2.800006e-01 Photon flux (15-150 keV) in 11.42 sec: 0.210089 ( -0.135509 0.182435 ) ph/cm2/s Energy fluence (15-150 keV) : 2.18805e-07 ( 0 0 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 0.564 sec. to 1.564 sec. Spectral model in power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.18223 ( -0.438047 0.45594 ) Norm@50keV : 1.61868E-02 ( -0.00351224 0.00343833 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 54.52 using 59 PHA bins. # Reduced chi-squared = 0.9565 for 57 degrees of freedom # Null hypothesis probability = 5.686573e-01 Photon flux (15-150 keV) in 1 sec: 1.89529 ( -0.43825 0.43816 ) ph/cm2/s Energy fluence (15-150 keV) : 1.65082e-07 ( -3.74322e-08 3.72059e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.564 sec. to 1.564 sec. Spectral model in the cutoff power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.18174 ( -0.401707 0.507366 ) Epeak [keV] : 1.00000E+04 ( -10000 -10000 ) Norm@50keV : 1.62703E-02 ( -0.00341924 -0.0162702 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 54.55 using 59 PHA bins. # Reduced chi-squared = 0.9740 for 56 degrees of freedom # Null hypothesis probability = 5.300679e-01 Photon flux (15-150 keV) in 1 sec: 1.89729 ( -0.44078 0.43587 ) ph/cm2/s Energy fluence (15-150 keV) : 1.64892e-07 ( -3.73216e-08 3.7368e-08 ) ergs/cm2
Time-resolved spectra
Distribution
T90 vs. Hardness ratio plot
T90 = 10.896 sec. Hardness ratio (energy fluence ratio) = 1.60568452733
S(15-50 keV) vs. S(50-150 keV) plot
S(15-50 keV) = 1.9340474e-07 S(50-150 keV) = 3.857001e-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 = -6.070552152356010E-01, IMY = 6.676171462328306E-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: -157.635400 -9.760000 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 125.7408 6.7196 2.3 40.4 103.3 4.0930 4.9 ------ UNKNOWN 139.5220 -32.2466 3.2 48.9 44.4 3.2218 3.6 ------ UNKNOWN 185.5962 -22.7606 3.3 37.1 -16.2 0.8675 3.5 ------ UNKNOWN
Pre-slew background subtracted image of 15-350 keV band
Time interval of the image: -9.760000 1.664000 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 196.6527 41.9691 1.3 42.1 -132.3 0.9463 8.7 ------ UNKNOWN
Post-slew image of 15-350 keV band
Time interval of the image: 180.364600 962.993000 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 208.3439 -13.6792 3.0 56.7 3.0 9.9849 3.9 ------ UNKNOWN 189.2589 84.6124 2.4 42.7 -164.4 6.0298 4.7 ------ UNKNOWN 226.1379 31.8718 2.7 25.5 -59.7 3.4298 4.3 ------ UNKNOWN 241.1902 50.8025 3.4 31.4 -105.2 3.6663 3.4 ------ UNKNOWN 238.6447 8.0985 3.0 50.1 -43.1 11.9882 3.8 ------ UNKNOWN