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 Oct 19 15:31:45 EDT 2024
Host Name: batproc1
Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger1221874
======================================================================
Trigger: 01221874 Segment: 000
BAT Trigger Time: 734855246.4 [s; MET]
Trigger Stop: 734855247.424 [s; MET]
UTC: 2024-04-15T06:26:53.127400 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 129.165633407651 Dec: 73.1465418206604 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 7.83
Image Trigger?: NO
Rate S/N Ratio: 10.3923048454133 [ if not an image trigger ]
Image S/N Ratio: 7.83
Analysis Position: [ source = BAT ]
RA: 129.165633407651 Dec: 73.1465418206604 [deg; J2000]
Refined Position: [ source = BAT pre-slew burst ]
RA: 129.190395822502 Dec: 73.1549325599179 [deg; J2000]
{ 08h 36m 45.7s , +73d 09' 17.8" }
+/- 1.08446162394135 [arcmin] (estimated 90% radius based on SNR)
+/- 0.446074622738062 [arcmin] (formal 1-sigma fit error)
SNR: 27.0902115757204
Angular difference between the analysis and refined position is 0.662507 arcmin
Partial Coding Fraction: 0.6015625 [ including projection effects ]
Duration
T90: 30.8000000715256 +/- 3.81488454394739
Measured from: 0.600000023841858
to: 31.4000000953674 [s; relative to TRIGTIME]
T50: 3.90400004386902 +/- 0.688743789583928
Measured from: 4.51999998092651
to: 8.42400002479553 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 5.10000002384186
to: 6.10000002384186 [s; relative to TRIGTIME]
Total Fluence
Measured from: -0.695999979972839
to: 37.5119999647141 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 1.398651 1.075446 0.524292 0.051676
0.056659 0.057990 0.049302 0.042527 [error]
Peak 0.232587 0.188811 0.071172 0.010172
0.013683 0.013754 0.009914 0.007643 [error]
[ fluence units of on-axis counts / fully illuminated detector ]
======================================================================
====== Table of the duration information =============================
Value tstart tstop
T100 38.208 -0.696 37.512
T90 30.800 0.600 31.400
T50 3.904 4.520 8.424
Peak 1.000 5.100 6.100
====== 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 -2.287 -0.139 0.134 - - - 4.12e-03 -3.54e-04 3.48e-04 44.470 57
CPL -2.356 -0.382 0.412 207.603 N/A N/A 3.75e-03 N/A N/A 44.300 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 -2.350 -0.169 0.161 - - - 2.49e-02 -2.82e-03 2.77e-03 49.640 57
CPL -1.984 1.984 0.478 1.718 -1.134 0.051 4.08e-02 -7.15e-03 7.27e-03 50.050 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 4.23e-07 4.84e-07 3.97e-07 5.44e-07 1.50e-06 1.85e-06 erg/cm2
90%_error_low -3.87e-08 -2.99e-08 -4.76e-08 -1.21e-07 -1.05e-07 -1.76e-07 erg/cm2
90%_error_hi 3.96e-08 2.98e-08 4.87e-08 1.43e-07 1.06e-07 1.92e-07 erg/cm2
Peak flux PL 2.33e+00 1.43e+00 5.59e-01 2.95e-01 4.47e+00 4.61e+00 ph/cm2/s
90%_error_low -2.65e-01 -1.17e-01 -8.30e-02 -7.51e-02 -3.66e-01 -3.72e-01 ph/cm2/s
90%_error_hi 2.70e-01 1.16e-01 8.46e-02 8.99e-02 3.66e-01 3.72e-01 ph/cm2/s
Fluence CPL 4.03e-07 4.78e-07 3.55e-07 1.96e-07 1.45e-06 1.65e-06 erg/cm2
90%_error_low -3.21e-08 -1.15e-08 -1.13e-08 1.40e-07 -9.93e-08 -1.83e-07 erg/cm2
90%_error_hi 3.66e-08 4.91e-08 9.47e-08 6.11e-07 1.31e-07 2.24e-07 erg/cm2
Peak flux CPL 2.25e+00 1.39e+00 5.53e-01 1.26e-01 4.40e+00 4.45e+00 ph/cm2/s
90%_error_low -2.37e-01 -2.90e-02 -9.42e-02 -2.23e-02 -3.50e-01 -3.51e-01 ph/cm2/s
90%_error_hi 2.57e-01 2.12e-01 8.96e-02 1.46e-01 3.61e-01 3.69e-01 ph/cm2/s
======================================================================
Image
Pre-slew 15.0-350.0 keV image (Event data)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name 129.1904 73.1549 0.0071 27.1114 -111.1573 3.2113232 27.090 TRIG_01221874 Foreground time interval of the image: -0.696 37.512 (delta_t = 38.208 [sec]) Background time interval of the image: -121.699 -0.696 (delta_t = 121.003 [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 -0.696 sec. to 37.512 sec. Spectral model in power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -2.2865 ( -0.138616 0.133511 ) Norm@50keV : 4.12121E-03 ( -0.000354428 0.000348378 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared 44.47 using 59 bins. Reduced chi-squared = 0.780175 # Null hypothesis probability of 8.87e-01 with 57 degrees of freedom Photon flux (15-150 keV) in 38.21 sec: 0.714927 ( -0.044672 0.044794 ) ph/cm2/s Energy fluence (15-150 keV) : 1.50147e-06 ( -1.04918e-07 1.06349e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.696 sec. to 37.512 sec. Spectral model in the cutoff power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -2.35632 ( -0.378688 0.414652 ) Epeak [keV] : 207.603 ( ) Norm@50keV : 3.75480E-03 ( ) ------------------------------------------------------------ #Fit statistic : Chi-Squared 44.30 using 59 bins. Reduced chi-squared = 0.791071 # Null hypothesis probability of 8.71e-01 with 56 degrees of freedom Photon flux (15-150 keV) in 38.21 sec: 0.715589 ( -0.089255 0.046996 ) ph/cm2/s Energy fluence (15-150 keV) : 1.45388e-06 ( -9.92566e-08 1.30825e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 5.100 sec. to 6.100 sec. Spectral model in power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -2.35019 ( -0.168649 0.16069 ) Norm@50keV : 2.48534E-02 ( -0.00282076 0.00276736 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared 49.64 using 59 bins. Reduced chi-squared = 0.870877 # Null hypothesis probability of 7.45e-01 with 57 degrees of freedom Photon flux (15-150 keV) in 1 sec: 4.46851 ( -0.36571 0.36602 ) ph/cm2/s Energy fluence (15-150 keV) : 2.39889e-07 ( -2.19123e-08 2.22007e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 5.100 sec. to 6.100 sec. Spectral model in the cutoff power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.99197 ( 1.99197 0.485845 ) Epeak [keV] : 0.918644 ( -0.334479 0.849885 ) Norm@50keV : 4.01782E-02 ( -0.00657057 0.00785137 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared 50.03 using 59 bins. Reduced chi-squared = 0.893393 # Null hypothesis probability of 6.99e-01 with 56 degrees of freedom Photon flux (15-150 keV) in 1 sec: 4.39842 ( -0.35017 0.36104 ) ph/cm2/s Energy fluence (15-150 keV) : 2.32129e-07 ( -2.1969e-08 2.36059e-08 ) ergs/cm2
Time-resolved spectra
Distribution
T90 vs. Hardness ratio plot
T90 = 30.8 sec. Hardness ratio (energy fluence ratio) = 0.819936425942
S(15-50 keV) vs. S(50-150 keV) plot
S(15-50 keV) = 9.069162e-07 S(50-150 keV) = 5.94541e-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 = -1.847879492131420E-01, IMY = 4.774667470488252E-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: -121.699400 -0.696000 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 254.5213 35.3615 12.3 50.3 4.4 0.4645 0.9 3.3 Her X-1 143.2516 33.9365 2.4 36.2 169.3 1.3085 4.8 ------ UNKNOWN 270.9871 37.8652 3.1 57.2 -9.9 4.2279 3.7 ------ UNKNOWN
Pre-slew background subtracted image of 15-350 keV band
Time interval of the image: -0.696000 37.512000 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 254.4304 35.3786 7.2 50.2 4.5 -0.4676 -1.6 2.5 Her X-1 127.2250 19.4410 2.5 56.2 173.7 2.4191 4.5 ------ UNKNOWN 124.9071 26.9535 2.4 51.4 -178.8 1.1301 4.9 ------ UNKNOWN 252.7152 43.8262 2.4 43.3 -2.4 0.8201 4.8 ------ UNKNOWN 153.6306 68.1824 2.3 18.1 -117.8 0.4931 5.0 ------ UNKNOWN 129.1905 73.1549 0.4 27.1 -111.2 3.2112 27.1 ------ UNKNOWN
Post-slew image of 15-350 keV band
Time interval of the image: