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 04:37:02 EST 2018
Host Name: bat1
Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger796778
======================================================================
Trigger: 00796778 Segment: 000
BAT Trigger Time: 534772661.824 [s; MET]
Trigger Stop: 534772665.92 [s; MET]
UTC: 2017-12-12T11:57:21.680200 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 293.900492945572 Dec: 20.5684683791818 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 7.35
Image Trigger?: NO
Rate S/N Ratio: 9.48683298050514 [ if not an image trigger ]
Image S/N Ratio: 7.35
Analysis Position: [ source = BAT ]
RA: 293.900492945572 Dec: 20.5684683791818 [deg; J2000]
Refined Position: [ source = BAT pre-slew burst ]
RA: 293.921919072071 Dec: 20.5975380359236 [deg; J2000]
{ 19h 35m 41.3s , +20d 35' 51.1" }
+/- 1.67770096960655 [arcmin] (estimated 90% radius based on SNR)
+/- 0.796348538935564 [arcmin] (formal 1-sigma fit error)
SNR: 14.52437945096
Angular difference between the analysis and refined position is 2.119099 arcmin
Partial Coding Fraction: 0.609375 [ including projection effects ]
Duration
T90: 304 +/- 64
Measured from: -28.8240000009537
to: 275.175999999046 [s; relative to TRIGTIME]
T50: 80 +/- 16
Measured from: 3.17599999904633
to: 83.1759999990463 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 90.6759999990463
to: 91.6759999990463 [s; relative to TRIGTIME]
Total Fluence
Measured from: -28.8240000009537
to: 371.175999999046 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 2.892025 2.581113 1.102158 0.079162
0.139289 0.142056 0.124417 0.118717 [error]
Peak 0.035697 0.028824 0.012514 0.002062
0.007006 0.007280 0.006203 0.005607 [error]
[ fluence units of on-axis counts / fully illuminated detector ]
======================================================================
====== Table of the duration information =============================
Value tstart tstop
T100 400.000 -28.824 371.176
T90 304.000 -28.824 275.176
T50 80.000 3.176 83.176
Peak 1.000 90.676 91.676
====== 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 -2.206 -0.139 0.134 - - - 8.88e-04 -7.95e-05 7.84e-05 58.360 57
CPL -1.720 -0.284 0.637 22.867 -22.037 12.989 1.72e-03 -6.59e-04 2.35e-03 56.110 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 -2.255 -0.556 0.458 - - - 4.07e-03 -1.55e-03 1.50e-03 54.140 57
CPL -2.274 -1.286 3.300 441.886 N/A N/A 3.95e-03 N/A N/A 54.140 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 8.84e-07 1.06e-06 9.19e-07 1.36e-06 3.34e-06 4.22e-06 erg/cm2
90%_error_low -8.17e-08 -6.95e-08 -1.14e-07 -3.06e-07 -2.54e-07 -4.43e-07 erg/cm2
90%_error_hi 8.34e-08 6.94e-08 1.16e-07 3.65e-07 2.59e-07 4.86e-07 erg/cm2
Peak flux PL 3.48e-01 2.25e-01 9.42e-02 5.38e-02 6.94e-01 7.20e-01 ph/cm2/s
90%_error_low -9.97e-02 -5.87e-02 -4.39e-02 -3.55e-02 -1.61e-01 -1.72e-01 ph/cm2/s
90%_error_hi 1.02e-01 5.62e-02 4.90e-02 6.40e-02 1.62e-01 1.75e-01 ph/cm2/s
Fluence CPL 8.48e-07 1.11e-06 8.75e-07 5.57e-07 3.16e-06 3.39e-06 erg/cm2
90%_error_low -9.31e-08 -8.79e-08 -1.40e-07 -3.37e-07 -3.09e-07 -4.79e-07 erg/cm2
90%_error_hi 9.18e-08 9.32e-08 1.32e-07 7.13e-07 3.27e-07 8.17e-07 erg/cm2
Peak flux CPL 3.48e-01 2.25e-01 9.43e-02 5.80e-02 6.94e-01 7.23e-01 ph/cm2/s
90%_error_low -1.02e-01 -1.27e-01 -3.89e-02 -5.80e-02 -1.61e-01 N/A ph/cm2/s
90%_error_hi 1.02e-01 5.63e-02 4.71e-02 1.29e-01 1.63e-01 N/A ph/cm2/s
======================================================================
Image
Pre-slew 15.0-350.0 keV image (Event data)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name 293.9219 20.5975 0.0132 24.1122 -107.3656 2.2499510 14.524 TRIG_00796778 Foreground time interval of the image: -28.824 34.677 (delta_t = 63.501 [sec]) Background time interval of the image: -618.323 -601.424 (delta_t = 16.899 [sec]) -239.824 -28.824 (delta_t = 211.000 [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 -28.824 sec. to 371.176 sec. Spectral model in power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -2.20637 ( -0.138784 0.13364 ) Norm@50keV : 8.87783E-04 ( -7.95136e-05 7.84258e-05 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 58.36 using 59 PHA bins. # Reduced chi-squared = 1.024 for 57 degrees of freedom # Null hypothesis probability = 4.250403e-01 Photon flux (15-150 keV) in 400 sec: 0.147484 ( -0.009575 0.009584 ) ph/cm2/s Energy fluence (15-150 keV) : 3.34249e-06 ( -2.54042e-07 2.58569e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -28.824 sec. to 371.176 sec. Spectral model in the cutoff power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.71967 ( -0.283565 0.637311 ) Epeak [keV] : 22.8673 ( -22.0394 12.9864 ) Norm@50keV : 1.71830E-03 ( -0.000659424 0.0023513 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 56.11 using 59 PHA bins. # Reduced chi-squared = 1.002 for 56 degrees of freedom # Null hypothesis probability = 4.706460e-01 Photon flux (15-150 keV) in 400 sec: 0.143756 ( -0.010399 0.010103 ) ph/cm2/s Energy fluence (15-150 keV) : 3.15566e-06 ( -3.08774e-07 3.26751e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 90.676 sec. to 91.676 sec. Spectral model in power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -2.25497 ( -0.556328 0.457902 ) Norm@50keV : 4.06798E-03 ( -0.00155314 0.00150487 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 54.14 using 59 PHA bins. # Reduced chi-squared = 0.9499 for 57 degrees of freedom # Null hypothesis probability = 5.829448e-01 Photon flux (15-150 keV) in 1 sec: 0.693615 ( -0.161341 0.161571 ) ph/cm2/s Energy fluence (15-150 keV) : 3.8578e-08 ( -1.17196e-08 1.26987e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 90.676 sec. to 91.676 sec. Spectral model in the cutoff power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -2.27433 ( -1.2872 3.29903 ) Epeak [keV] : 441.886 ( ) Norm@50keV : 3.95143E-03 ( ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 54.14 using 59 PHA bins. # Reduced chi-squared = 0.9668 for 56 degrees of freedom # Null hypothesis probability = 5.454594e-01 Photon flux (15-150 keV) in 1 sec: 0.693616 ( -0.160902 0.162575 ) ph/cm2/s Energy fluence (15-150 keV) : 0 ( 0 0 ) ergs/cm2
Time-resolved spectra
Distribution
T90 vs. Hardness ratio plot
T90 = 304.0 sec. Hardness ratio (energy fluence ratio) = 0.866762013838
S(15-50 keV) vs. S(50-150 keV) plot
S(15-50 keV) = 1.9442256e-06 S(50-150 keV) = 1.3983124e-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 = -1.335876544575510E-01, IMY = 4.271762430992510E-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: -618.323400 -601.424000 -239.824000 -28.824000 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 254.3011 35.3987 6.5 41.9 -41.6 0.8454 1.8 8.4 Her X-1 288.9530 11.0087 4.3 34.8 -107.2 1.2378 2.7 9.9 GRS 1915+105 299.5824 35.2120 1.0 9.2 -92.2 2.8125 12.1 0.7 Cyg X-1 308.0507 40.9101 2.1 0.6 -139.8 1.1828 5.4 3.7 Cyg X-3 326.1841 38.3255 4.7 14.2 135.6 0.5946 2.5 0.6 Cyg X-2 15.3295 84.4397 3.2 46.5 45.6 3.2519 3.6 ------ UNKNOWN 357.5349 17.5377 2.6 48.4 142.9 4.6679 4.5 ------ UNKNOWN 201.5747 71.5567 2.8 55.8 17.1 5.4513 4.1 ------ UNKNOWN 341.6814 -6.4428 2.4 57.0 177.6 7.7005 4.8 ------ UNKNOWN 220.5873 51.0887 2.4 57.6 -9.5 5.3699 4.7 ------ UNKNOWN 281.4229 19.6176 2.5 31.5 -87.4 1.7896 4.6 ------ UNKNOWN
Pre-slew background subtracted image of 15-350 keV band
Time interval of the image: -28.824000 34.676580 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 254.5490 35.3982 13.7 41.7 -41.7 -0.1909 -0.8 5.6 Her X-1 288.6918 10.8401 9.1 35.1 -106.9 -0.3090 -1.3 8.9 GRS 1915+105 299.5709 35.3917 5.2 9.0 -91.4 -0.2436 -2.2 11.4 Cyg X-1 308.2578 41.0536 40.0 0.5 -157.7 -0.0329 -0.3 9.0 Cyg X-3 326.1301 38.1374 9.2 14.2 136.4 -0.1460 -1.2 11.2 Cyg X-2 352.8231 67.3130 1.7 35.2 66.6 1.5339 6.7 ------ UNKNOWN 293.9219 20.5975 0.8 24.1 -107.4 2.2505 14.5 ------ UNKNOWN
Post-slew image of 15-350 keV band
Time interval of the image: 80.476620 841.876590 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 254.4915 35.3166 7.0 37.5 -7.2 -1.2535 -1.6 2.3 Her X-1 268.2575 -1.3904 10.9 33.4 -77.0 1.1707 1.1 7.6 SW J1753.5-0127 273.9762 -13.8898 6.3 39.7 -97.7 4.6577 1.8 9.0 GX 17+2 288.8318 10.8931 2.9 10.9 -101.4 2.6603 4.0 3.7 GRS 1915+105 299.6057 35.2162 1.1 15.5 68.9 5.6480 10.3 1.2 Cyg X-1 308.0305 40.9917 2.3 23.7 78.4 3.5100 5.0 4.3 Cyg X-3 326.0772 38.2219 12.3 32.8 101.6 1.0527 0.9 7.5 Cyg X-2 268.6624 68.5190 3.5 50.4 39.4 10.0053 3.2 ------ UNKNOWN 258.2353 48.6140 3.2 39.9 14.2 2.9104 3.5 ------ UNKNOWN 288.8194 -2.2234 2.5 23.4 -116.0 3.2218 4.7 ------ UNKNOWN 232.2246 26.1549 3.7 56.4 -20.5 7.6194 3.2 ------ UNKNOWN 243.8259 13.0945 4.8 48.3 -39.5 4.1968 2.4 ------ UNKNOWN 275.8384 -15.1979 3.7 40.0 -101.1 7.7406 3.1 ------ UNKNOWN