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: Thu Jun 19 21:39:51 EDT 2025
Host Name: batproc1
Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger1285812
======================================================================
Trigger: 01285812 Segment: 000
BAT Trigger Time: 759818744 [s; MET]
Trigger Stop: 759818808 [s; MET]
UTC: 2025-01-29T04:45:09.019520 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 198.689488755722 Dec: 5.03870168426934 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 10.13
Image Trigger?: YES
Rate S/N Ratio: 0 [ if not an image trigger ]
Image S/N Ratio: 10.13
Analysis Position: [ source = BAT ]
RA: 198.689488755722 Dec: 5.03870168426934 [deg; J2000]
Refined Position: [ source = BAT pre-slew burst ]
RA: 198.700286273275 Dec: 5.02617248282543 [deg; J2000]
{ 13h 14m 48.1s , +05d 01' 34.2" }
+/- 1.71624213547337 [arcmin] (estimated 90% radius based on SNR)
+/- 0.759308388291551 [arcmin] (formal 1-sigma fit error)
SNR: 14.0606743913087
Angular difference between the analysis and refined position is 0.990764 arcmin
Partial Coding Fraction: 0.84375 [ including projection effects ]
Duration
T90: 272.183999896049 +/- 22.6735377924198
Measured from: -32.0319999456406
to: 240.151999950409 [s; relative to TRIGTIME]
T50: 132.707999944687 +/- 8.69233704460982
Measured from: 63.555999994278
to: 196.263999938965 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 184.120000004768
to: 185.120000004768 [s; relative to TRIGTIME]
Total Fluence
Measured from: -62.5440000295639
to: 302.62399995327 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 3.837545 3.802232 1.726056 0.243849
0.119062 0.122201 0.102220 0.086068 [error]
Peak 0.052118 0.075098 0.036885 0.002093
0.006766 0.007004 0.005905 0.004608 [error]
[ fluence units of on-axis counts / fully illuminated detector ]
======================================================================
====== Table of the duration information =============================
Value tstart tstop
T100 365.168 -62.544 302.624
T90 272.184 -32.032 240.152
T50 132.708 63.556 196.264
Peak 1.000 184.120 185.120
====== 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 -2.138 -0.089 0.087 - - - 1.42e-03 -7.35e-05 7.27e-05 55.990 57
CPL -1.989 -0.012 0.378 3.136 -0.853 32.594 1.73e-03 -1.50e-04 1.04e-03 55.260 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 -1.778 -0.197 0.189 - - - 9.78e-03 -1.33e-03 1.31e-03 48.420 57
CPL -0.415 -0.923 1.243 48.943 -8.852 20.986 5.97e-02 -5.97e-02 2.63e-01 41.380 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 1.21e-06 1.51e-06 1.37e-06 2.17e-06 4.84e-06 6.27e-06 erg/cm2
90%_error_low -8.19e-08 -6.35e-08 -9.97e-08 -3.09e-07 -2.24e-07 -4.09e-07 erg/cm2
90%_error_hi 8.37e-08 6.36e-08 1.01e-07 3.43e-07 2.25e-07 4.32e-07 erg/cm2
Peak flux PL 5.26e-01 4.49e-01 2.62e-01 2.28e-01 1.34e+00 1.47e+00 ph/cm2/s
90%_error_low -8.59e-02 -5.26e-02 -4.51e-02 -6.66e-02 -1.57e-01 -1.75e-01 ph/cm2/s
90%_error_hi 8.86e-02 5.26e-02 4.54e-02 8.10e-02 1.57e-01 1.76e-01 ph/cm2/s
Fluence CPL 1.19e-06 1.54e-06 1.37e-06 1.58e-06 4.76e-06 5.62e-06 erg/cm2
90%_error_low -6.85e-08 -6.67e-08 -1.06e-07 -6.75e-07 -2.85e-07 -7.11e-07 erg/cm2
90%_error_hi 7.09e-08 8.16e-08 1.04e-07 6.45e-07 2.48e-07 8.05e-07 erg/cm2
Peak flux CPL 4.64e-01 5.29e-01 2.60e-01 4.90e-02 1.29e+00 1.30e+00 ph/cm2/s
90%_error_low -9.87e-02 -7.48e-02 -6.09e-02 -4.90e-02 -1.59e-01 -1.64e-01 ph/cm2/s
90%_error_hi 9.95e-02 7.91e-02 5.56e-02 8.42e-02 1.59e-01 1.69e-01 ph/cm2/s
======================================================================
Image
Pre-slew 15.0-350.0 keV image (Event data)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name 198.7003 5.0262 0.0137 27.3282 1.1866 2.6138861 14.061 TRIG_01285812 Foreground time interval of the image: -62.544 74.301 (delta_t = 136.845 [sec]) Background time interval of the image: -239.000 -62.544 (delta_t = 176.456 [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 -62.544 sec. to 302.624 sec. Spectral model in power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -2.13848 ( -0.0887688 0.0870656 ) Norm@50keV : 1.42137E-03 ( -7.34603e-05 7.27364e-05 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared 55.99 using 59 bins. Reduced chi-squared = 0.982281 # Null hypothesis probability of 5.13e-01 with 57 degrees of freedom Photon flux (15-150 keV) in 365.2 sec: 0.227981 ( -0.010137 0.010167 ) ph/cm2/s Energy fluence (15-150 keV) : 4.84328e-06 ( -2.23721e-07 2.2535e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -62.544 sec. to 302.624 sec. Spectral model in the cutoff power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.9857 ( -0.014793 0.375234 ) Epeak [keV] : 4.03456 ( -1.75172 31.6958 ) Norm@50keV : 1.72848E-03 ( -0.000148797 0.00103778 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared 55.25 using 59 bins. Reduced chi-squared = 0.986607 # Null hypothesis probability of 5.03e-01 with 56 degrees of freedom Photon flux (15-150 keV) in 365.2 sec: 0.227787 ( -0.010019 0.010428 ) ph/cm2/s Energy fluence (15-150 keV) : 4.7572e-06 ( -2.85009e-07 2.47988e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 184.120 sec. to 185.120 sec. Spectral model in power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.77816 ( -0.196723 0.188559 ) Norm@50keV : 9.78167E-03 ( -0.00132999 0.00130887 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared 48.42 using 59 bins. Reduced chi-squared = 0.849474 # Null hypothesis probability of 7.84e-01 with 57 degrees of freedom Photon flux (15-150 keV) in 1 sec: 1.33672 ( -0.15652 0.15653 ) ph/cm2/s Energy fluence (15-150 keV) : 9.01467e-08 ( -1.24326e-08 1.26502e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 184.120 sec. to 185.120 sec. Spectral model in the cutoff power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -0.414605 ( -0.925078 1.24024 ) Epeak [keV] : 48.9428 ( -8.82353 21.0138 ) Norm@50keV : 5.97234E-02 ( -0.0599955 0.262276 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared 41.38 using 59 bins. Reduced chi-squared = 0.738929 # Null hypothesis probability of 9.28e-01 with 56 degrees of freedom Photon flux (15-150 keV) in 1 sec: 1.29350 ( -0.15868 0.15905 ) ph/cm2/s Energy fluence (15-150 keV) : 8.01512e-08 ( -1.30052e-08 1.39467e-08 ) ergs/cm2
Time-resolved spectra
Distribution
T90 vs. Hardness ratio plot
T90 = 272.184 sec. Hardness ratio (energy fluence ratio) = 0.908510714253
S(15-50 keV) vs. S(50-150 keV) plot
S(15-50 keV) = 2.724262e-06 S(50-150 keV) = 2.119068e-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 = 5.166513247353672E-01, IMY = -1.070140368864476E-02
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: -239.000000 -62.544000 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 145.3641 38.9356 2.4 42.4 117.7 6.8603 4.7 ------ UNKNOWN 247.4973 33.4358 2.5 41.5 -102.1 5.3904 4.6 ------ UNKNOWN
Pre-slew background subtracted image of 15-350 keV band
Time interval of the image: -62.544000 74.300590 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 198.7003 5.0262 0.8 27.3 1.2 2.6131 14.1 ------ UNKNOWN 249.2819 67.4893 2.1 46.0 -151.8 1.7769 5.4 ------ UNKNOWN
Post-slew image of 15-350 keV band
Time interval of the image: 146.500600 530.188100 531.000000 963.055100 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 164.1195 32.5298 3.2 42.4 117.7 22.4674 3.7 ------ UNKNOWN 186.5460 -44.2251 3.8 50.4 -5.9 5.4272 3.0 ------ UNKNOWN 228.6390 -12.2125 2.7 34.4 -76.9 7.9010 4.2 ------ UNKNOWN 242.8632 12.9359 3.0 44.3 -120.5 17.2613 3.9 ------ UNKNOWN