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 v2.48
Process Start Time: Sat Mar 9 14:03:00 EST 2024
Host Name: batproc1
Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger1208389
======================================================================
Trigger: 01208389 Segment: 000
BAT Trigger Time: 726773877.696 [s; MET]
Trigger Stop: 726773878.208 [s; MET]
UTC: 2024-01-12T17:37:24.977140 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 270.644133237923 Dec: 24.4866348399557 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 20.03
Image Trigger?: NO
Rate S/N Ratio: 74.0067564483136 [ if not an image trigger ]
Image S/N Ratio: 20.03
Analysis Position: [ source = BAT ]
RA: 270.644133237923 Dec: 24.4866348399557 [deg; J2000]
Refined Position: [ source = BAT pre-slew burst ]
RA: 270.641616577814 Dec: 24.4948479879338 [deg; J2000]
{ 18h 02m 34.0s , +24d 29' 41.5" }
+/- 0.6283752618321 [arcmin] (estimated 90% radius based on SNR)
+/- 0.177664985334059 [arcmin] (formal 1-sigma fit error)
SNR: 59.0713421191252
Angular difference between the analysis and refined position is 0.511589 arcmin
Partial Coding Fraction: 0.609375 [ including projection effects ]
Duration
T90: 4.92399990558624 +/- 0.335451964872326
Measured from: 0.180000066757202
to: 5.10399997234344 [s; relative to TRIGTIME]
T50: 2.53999996185303 +/- 0.0632455984401142
Measured from: 0.687999963760376
to: 3.2279999256134 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 0.128000020980835
to: 1.12800002098083 [s; relative to TRIGTIME]
Total Fluence
Measured from: -0.375999927520752
to: 7.21599996089935 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 1.372531 1.661346 0.954371 0.187617
0.031840 0.033766 0.027856 0.018777 [error]
Peak 0.448630 0.541397 0.301905 0.058281
0.015607 0.016793 0.013624 0.008024 [error]
[ fluence units of on-axis counts / fully illuminated detector ]
======================================================================
====== Table of the duration information =============================
Value tstart tstop
T100 7.592 -0.376 7.216
T90 4.924 0.180 5.104
T50 2.540 0.688 3.228
Peak 1.000 0.128 1.128
====== 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: 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 -1.939 -0.053 0.053 - - - 3.52e-02 -1.02e-03 1.02e-03 67.000 57
CPL -1.484 -0.224 0.237 57.162 -6.619 10.872 5.89e-02 -1.30e-02 1.78e-02 54.440 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 -1.962 -0.072 0.071 - - - 8.46e-02 -3.60e-03 3.58e-03 55.230 57
CPL -1.456 -0.289 0.310 52.275 -7.970 11.864 1.54e-01 -4.35e-02 6.68e-02 45.850 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 5.16e-07 7.26e-07 7.57e-07 1.45e-06 2.46e-06 3.45e-06 erg/cm2
90%_error_low -2.58e-08 -2.16e-08 -2.91e-08 -1.17e-07 -7.04e-08 -1.40e-07 erg/cm2
90%_error_hi 2.63e-08 2.16e-08 2.91e-08 1.24e-07 7.05e-08 1.44e-07 erg/cm2
Peak flux PL 5.43e+00 4.17e+00 2.14e+00 1.58e+00 1.25e+01 1.33e+01 ph/cm2/s
90%_error_low -3.56e-01 -1.71e-01 -1.17e-01 -1.67e-01 -5.28e-01 -5.31e-01 ph/cm2/s
90%_error_hi 3.65e-01 1.70e-01 1.17e-01 1.78e-01 5.29e-01 5.32e-01 ph/cm2/s
Fluence CPL 4.71e-07 7.51e-07 7.75e-07 8.05e-07 2.38e-06 2.80e-06 erg/cm2
90%_error_low -3.27e-08 -2.49e-08 -3.15e-08 -1.88e-07 -8.07e-08 -2.07e-07 erg/cm2
90%_error_hi 3.32e-08 2.51e-08 3.17e-08 2.57e-07 8.05e-08 2.69e-07 erg/cm2
Peak flux CPL 4.96e+00 4.34e+00 2.21e+00 9.36e-01 1.21e+01 1.24e+01 ph/cm2/s
90%_error_low -4.35e-01 -1.99e-01 -1.29e-01 -2.40e-01 -5.63e-01 -6.39e-01 ph/cm2/s
90%_error_hi 4.43e-01 2.02e-01 1.30e-01 3.24e-01 5.65e-01 6.65e-01 ph/cm2/s
======================================================================
Image
Pre-slew 15.0-350.0 keV image (Event data)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name 270.6416 24.4948 0.0033 34.9447 -37.6417 4.4226708 59.071 TRIG_01208389 Foreground time interval of the image: -0.376 7.216 (delta_t = 7.592 [sec]) Background time interval of the image: -239.696 -0.376 (delta_t = 239.320 [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 -0.376 sec. to 7.216 sec. Spectral model in power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.93891 ( -0.0530798 0.0526961 ) Norm@50keV : 3.51744E-02 ( -0.00102182 0.00101983 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared 67.00 using 59 bins. Reduced chi-squared = 1.17544 # Null hypothesis probability of 1.71e-01 with 57 degrees of freedom Photon flux (15-150 keV) in 7.592 sec: 5.13370 ( -0.16296 0.16364 ) ph/cm2/s Energy fluence (15-150 keV) : 2.45717e-06 ( -7.04276e-08 7.04721e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.376 sec. to 7.216 sec. Spectral model in the cutoff power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.48411 ( -0.224357 0.236798 ) Epeak [keV] : 57.1622 ( -6.61885 10.8724 ) Norm@50keV : 5.89337E-02 ( -0.0129751 0.0178308 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared 54.44 using 59 bins. Reduced chi-squared = 0.972143 # Null hypothesis probability of 5.34e-01 with 56 degrees of freedom Photon flux (15-150 keV) in 7.592 sec: 4.95570 ( -0.18157 0.1826 ) ph/cm2/s Energy fluence (15-150 keV) : 2.37655e-06 ( -8.06825e-08 8.04593e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 0.128 sec. to 1.128 sec. Spectral model in power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.96183 ( -0.0723254 0.0713177 ) Norm@50keV : 8.45518E-02 ( -0.00359542 0.00357808 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared 55.23 using 59 bins. Reduced chi-squared = 0.968947 # Null hypothesis probability of 5.42e-01 with 57 degrees of freedom Photon flux (15-150 keV) in 1 sec: 12.4662 ( -0.5278 0.5292 ) ph/cm2/s Energy fluence (15-150 keV) : 7.78538e-07 ( -3.22611e-08 3.23484e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.128 sec. to 1.128 sec. Spectral model in the cutoff power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.45639 ( -0.289208 0.310478 ) Epeak [keV] : 52.2749 ( -7.97027 11.8639 ) Norm@50keV : 0.153601 ( -0.0435334 0.0668204 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared 45.85 using 59 bins. Reduced chi-squared = 0.81875 # Null hypothesis probability of 8.31e-01 with 56 degrees of freedom Photon flux (15-150 keV) in 1 sec: 12.0957 ( -0.5633 0.5651 ) ph/cm2/s Energy fluence (15-150 keV) : 7.52575e-07 ( -3.56231e-08 3.55589e-08 ) ergs/cm2
Time-resolved spectra
Distribution
T90 vs. Hardness ratio plot
T90 = 4.924 sec. Hardness ratio (energy fluence ratio) = 1.03226222828
S(15-50 keV) vs. S(50-150 keV) plot
S(15-50 keV) = 1.221625e-06 S(50-150 keV) = 1.1548865e-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 = 5.533171433505845E-01, IMY = 4.267536605397633E-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: -239.696000 -0.376000 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 254.5052 35.3786 3.0 41.2 -10.6 1.9548 3.9 3.2 Her X-1 288.9103 10.8357 14.1 35.0 -76.7 0.4461 0.8 9.3 GRS 1915+105 299.5719 35.1831 1.9 9.0 -64.4 1.9822 5.9 1.4 Cyg X-1 308.1563 41.0236 4.8 1.0 -144.9 0.8171 2.4 4.7 Cyg X-3 326.2367 38.1179 0.0 14.9 168.6 -0.3048 -0.9 12.6 Cyg X-2 320.7866 73.4280 2.7 32.2 77.5 3.2262 4.2 ------ UNKNOWN 244.2249 34.8683 2.3 48.9 -5.9 3.0213 5.1 ------ UNKNOWN 318.9294 -3.7499 3.0 46.8 -125.5 5.5869 3.9 ------ UNKNOWN
Pre-slew background subtracted image of 15-350 keV band
Time interval of the image: -0.376000 7.216000 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 254.5048 35.2668 6.0 41.2 -10.7 -0.1580 -1.9 5.1 Her X-1 288.6827 11.0322 4.9 34.9 -76.2 0.2561 2.3 8.6 GRS 1915+105 299.7196 35.0181 0.0 9.1 -65.6 0.1091 2.0 12.7 Cyg X-1 307.9917 41.1449 0.0 0.8 -142.6 -0.0792 -1.4 12.7 Cyg X-3 326.3016 38.4004 4.9 14.8 167.5 -0.1341 -2.4 7.7 Cyg X-2 8.8234 42.9839 2.6 44.3 137.2 0.7792 4.4 ------ UNKNOWN 270.6416 24.4948 0.2 34.9 -37.6 4.4226 59.1 ------ UNKNOWN 351.0469 -2.8282 2.5 59.6 -162.7 1.6350 4.6 563.1 UNKNOWN 289.0376 4.2170 2.5 41.0 -81.0 1.0836 4.5 ------ UNKNOWN
Post-slew image of 15-350 keV band
Time interval of the image: 96.804600 236.004590 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 244.9747 -15.6330 3.1 47.3 -27.3 1.4526 3.8 0.5 Sco X-1 254.6804 35.2928 17.3 17.5 70.0 -0.1680 -0.7 11.3 Her X-1 268.3684 -1.4488 41.5 26.0 -56.8 0.0691 0.3 0.2 SW J1753.5-0127 273.9189 -14.0756 22.3 38.7 -67.0 0.2311 0.5 5.6 GX 17+2 288.7202 10.7489 0.0 22.0 -116.5 0.4624 2.0 12.7 GRS 1915+105 299.5536 35.2493 3.7 27.2 178.0 0.7268 3.1 3.4 Cyg X-1 308.1087 40.8287 11.3 35.2 171.1 0.2917 1.0 7.4 Cyg X-3 326.1219 38.3191 4.8 48.6 177.6 -1.4233 -2.4 2.3 Cyg X-2 240.7361 45.7608 3.5 32.1 77.2 1.5656 3.3 ------ UNKNOWN 264.6045 41.5587 2.9 17.8 103.3 0.9969 3.9 ------ UNKNOWN 302.0962 39.0631 2.7 30.3 171.7 1.0633 4.3 ------ UNKNOWN 254.8820 -4.8748 2.0 33.1 -32.2 1.4360 5.6 ------ UNKNOWN 255.7890 -16.0847 3.2 43.0 -40.8 1.4041 3.6 ------ UNKNOWN