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 Nov 16 12:06:18 EST 2024
Host Name: batproc1
Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger1231488
======================================================================
Trigger: 01231488 Segment: 000
BAT Trigger Time: 738644344.32 [s; MET]
Trigger Stop: 738644345.344 [s; MET]
UTC: 2024-05-29T02:58:30.788060 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 335.321551571704 Dec: 51.5552654293351 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 11.12
Image Trigger?: NO
Rate S/N Ratio: 25.2388589282479 [ if not an image trigger ]
Image S/N Ratio: 11.12
Analysis Position: [ source = BAT ]
RA: 335.321551571704 Dec: 51.5552654293351 [deg; J2000]
Refined Position: [ source = BAT pre-slew burst ]
RA: 335.340496218476 Dec: 51.5573055046231 [deg; J2000]
{ 22h 21m 21.7s , +51d 33' 26.3" }
+/- 0.870606769881079 [arcmin] (estimated 90% radius based on SNR)
+/- 0.352974617273414 [arcmin] (formal 1-sigma fit error)
SNR: 37.0754895626986
Angular difference between the analysis and refined position is 0.717247 arcmin
Partial Coding Fraction: 0.2617188 [ including projection effects ]
Duration
T90: 158.971999883652 +/- 12.9762226866818
Measured from: -37.0520000457764
to: 121.919999837875 [s; relative to TRIGTIME]
T50: 65.2400000095367 +/- 1.35625963921704
Measured from: -11.4680000543594
to: 53.7719999551773 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 0.167999982833862
to: 1.16799998283386 [s; relative to TRIGTIME]
Total Fluence
Measured from: -70.9160000085831
to: 227.451999902725 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 8.819169 11.500703 8.864284 2.816632
0.178972 0.192749 0.175111 0.156538 [error]
Peak 0.196038 0.307450 0.279123 0.109869
0.019487 0.023152 0.021851 0.017481 [error]
[ fluence units of on-axis counts / fully illuminated detector ]
======================================================================
====== Table of the duration information =============================
Value tstart tstop
T100 298.368 -70.916 227.452
T90 158.972 -37.052 121.920
T50 65.240 -11.468 53.772
Peak 1.000 0.168 1.168
====== 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 -1.604 -0.044 0.044 - - - 7.39e-03 -1.64e-04 1.64e-04 61.250 57
CPL -1.602 -0.044 0.140 9998.060 -9998.060 -9998.060 7.40e-03 -1.65e-04 1.10e-03 61.260 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 -1.422 -0.129 0.129 - - - 6.31e-02 -4.94e-03 4.94e-03 58.180 57
CPL -1.105 -0.380 0.534 150.699 -64.514 -150.699 9.00e-02 -3.02e-02 7.11e-02 56.920 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 3.10e-06 5.35e-06 7.04e-06 1.88e-05 2.06e-05 3.43e-05 erg/cm2
90%_error_low -1.45e-07 -1.43e-07 -1.92e-07 -1.18e-06 -4.70e-07 -1.27e-06 erg/cm2
90%_error_hi 1.48e-07 1.43e-07 1.92e-07 1.23e-06 4.70e-07 1.31e-06 erg/cm2
Peak flux PL 2.41e+00 2.54e+00 1.90e+00 2.29e+00 7.73e+00 9.14e+00 ph/cm2/s
90%_error_low -3.28e-01 -2.22e-01 -1.77e-01 -4.06e-01 -6.25e-01 -7.19e-01 ph/cm2/s
90%_error_hi 3.41e-01 2.20e-01 1.75e-01 4.53e-01 6.26e-01 7.21e-01 ph/cm2/s
Fluence CPL 3.10e-06 5.35e-06 7.02e-06 1.94e-05 2.07e-05 3.50e-05 erg/cm2
90%_error_low N/A -1.48e-07 -2.42e-07 -3.86e-06 -6.65e-07 -3.91e-06 erg/cm2
90%_error_hi N/A 1.92e-07 3.00e-07 -3.88e-07 3.97e-07 4.93e-07 erg/cm2
Peak flux CPL 2.26e+00 2.62e+00 1.97e+00 1.66e+00 7.65e+00 8.51e+00 ph/cm2/s
90%_error_low -3.92e-01 -2.51e-01 -2.08e-01 -6.45e-01 -6.35e-01 -9.26e-01 ph/cm2/s
90%_error_hi 4.03e-01 2.57e-01 2.13e-01 8.13e-01 6.36e-01 1.10e+00 ph/cm2/s
======================================================================
Image
Pre-slew 15.0-350.0 keV image (Event data)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name 335.3405 51.5573 0.0052 48.1586 -151.9850 16.4036322 37.075 TRIG_01231488 Foreground time interval of the image: -37.219 16.381 (delta_t = 53.600 [sec]) Background time interval of the image:
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 -70.916 sec. to 227.452 sec. Spectral model in power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.60396 ( -0.0440338 0.0439333 ) Norm@50keV : 7.38710E-03 ( -0.000164388 0.000164387 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared 61.25 using 59 bins. Reduced chi-squared = 1.07456 # Null hypothesis probability of 3.26e-01 with 57 degrees of freedom Photon flux (15-150 keV) in 298.4 sec: 0.950477 ( -0.024867 0.024981 ) ph/cm2/s Energy fluence (15-150 keV) : 2.06081e-05 ( -4.70478e-07 4.70326e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -70.916 sec. to 227.452 sec. Spectral model in the cutoff power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.60168 ( -0.0443068 0.139923 ) Epeak [keV] : 9998.06 ( -9998.47 -9998.47 ) Norm@50keV : 7.40469E-03 ( -0.000164768 0.001102 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared 61.26 using 59 bins. Reduced chi-squared = 1.09393 # Null hypothesis probability of 2.93e-01 with 56 degrees of freedom Photon flux (15-150 keV) in 298.4 sec: 0.953303 ( -0.038457 0.030165 ) ph/cm2/s Energy fluence (15-150 keV) : 2.06518e-05 ( -6.6525e-07 3.97024e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 0.168 sec. to 1.168 sec. Spectral model in power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.42166 ( -0.128931 0.128547 ) Norm@50keV : 6.31156E-02 ( -0.00494287 0.00493576 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared 58.18 using 59 bins. Reduced chi-squared = 1.0207 # Null hypothesis probability of 4.32e-01 with 57 degrees of freedom Photon flux (15-150 keV) in 1 sec: 7.72510 ( -0.62524 0.62614 ) ph/cm2/s Energy fluence (15-150 keV) : 6.07309e-07 ( -5.11871e-08 5.13945e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.168 sec. to 1.168 sec. Spectral model in the cutoff power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.10546 ( -0.379958 0.534364 ) Epeak [keV] : 150.699 ( -64.5153 -150.7 ) Norm@50keV : 8.99989E-02 ( -0.0301849 0.0710592 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared 56.92 using 59 bins. Reduced chi-squared = 1.01643 # Null hypothesis probability of 4.41e-01 with 56 degrees of freedom Photon flux (15-150 keV) in 1 sec: 7.65274 ( -0.63516 0.63564 ) ph/cm2/s Energy fluence (15-150 keV) : 5.99639e-07 ( -5.35292e-08 5.31007e-08 ) ergs/cm2
Time-resolved spectra
Distribution
T90 vs. Hardness ratio plot
T90 = 158.972 sec. Hardness ratio (energy fluence ratio) = 1.31592135968
S(15-50 keV) vs. S(50-150 keV) plot
S(15-50 keV) = 8.455176e-06 S(50-150 keV) = 1.2152788e-05
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 = -9.859501710022455E-01, IMY = 5.245699676983058E-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:
Pre-slew background subtracted image of 15-350 keV band
Time interval of the image: -37.219410 16.380600 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 288.8613 11.1571 0.0 42.5 127.2 0.3992 0.8 13.2 GRS 1915+105 299.6300 35.1838 3.1 43.0 165.8 1.3180 3.8 2.2 Cyg X-1 308.2321 41.0091 6.4 42.7 178.9 0.5603 1.8 6.5 Cyg X-3 326.1144 38.2094 45.1 35.0 -162.4 -0.0518 -0.3 7.3 Cyg X-2 346.8636 -47.3994 3.1 52.8 11.1 1.7508 3.8 ------ UNKNOWN 0.8108 -35.6424 2.5 48.0 -8.3 1.2137 4.6 ------ UNKNOWN 13.6209 -33.2493 4.6 54.4 -19.5 1.0496 2.5 ------ UNKNOWN 344.2351 36.1665 2.4 34.8 -136.8 1.2162 4.8 ------ UNKNOWN 335.3405 51.5573 0.3 48.2 -152.0 16.4024 37.1 ------ UNKNOWN
Post-slew image of 15-350 keV band
Time interval of the image: 107.180670 962.780600 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 299.5610 35.2195 1.1 30.3 86.4 14.2034 10.3 1.8 Cyg X-1 308.2004 40.9485 17.5 21.4 85.9 -0.6062 -0.7 4.1 Cyg X-3 325.9234 38.4061 0.0 14.7 45.3 1.1638 1.8 12.7 Cyg X-2 304.4402 43.0770 2.9 22.4 94.9 3.7764 4.0 ------ UNKNOWN 335.1454 29.4769 2.1 22.1 15.4 3.7741 5.5 ------ UNKNOWN 286.7340 74.9237 2.5 30.3 172.2 3.7026 4.6 ------ UNKNOWN 324.9970 64.6742 2.6 14.2 176.6 2.9484 4.5 ------ UNKNOWN 335.5604 51.5770 2.3 0.1 -84.5 3.6057 4.9 ------ UNKNOWN 286.6107 88.4444 2.1 37.4 -167.0 4.7705 5.4 ------ UNKNOWN 2.8309 73.5890 2.7 24.9 -147.0 3.0187 4.2 ------ UNKNOWN 142.3827 70.9059 2.2 57.2 -160.1 16.7461 5.3 ------ UNKNOWN 60.9783 61.3360 2.3 44.8 -122.3 15.3820 5.0 ------ UNKNOWN 28.8494 33.5595 2.2 42.2 -71.3 14.3838 5.1 ------ UNKNOWN