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: Wed Dec 18 16:23:46 EST 2024
Host Name: batproc1
Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger1270788
======================================================================
Trigger: 01270788 Segment: 000
BAT Trigger Time: 754436630.848 [s; MET]
Trigger Stop: 754436631.872 [s; MET]
UTC: 2024-11-27T21:43:16.235160 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 327.922202326549 Dec: -56.6853428664162 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 12.63
Image Trigger?: NO
Rate S/N Ratio: 12.0415945787923 [ if not an image trigger ]
Image S/N Ratio: 12.63
Analysis Position: [ source = BAT ]
RA: 327.922202326549 Dec: -56.6853428664162 [deg; J2000]
Refined Position: [ source = BAT pre-slew burst ]
RA: 327.904913192801 Dec: -56.6530126446624 [deg; J2000]
{ 21h 51m 37.2s , -56d 39' 10.8" }
+/- 1.67466139201442 [arcmin] (estimated 90% radius based on SNR)
+/- 0.700010636967412 [arcmin] (formal 1-sigma fit error)
SNR: 14.5620545666467
Angular difference between the analysis and refined position is 2.021823 arcmin
Partial Coding Fraction: 1.015625 [ including projection effects ]
Duration
T90: 25.9879999160767 +/- 3.64585245079972
Measured from: -19.4400000572205
to: 6.5479998588562 [s; relative to TRIGTIME]
T50: 8.42399990558624 +/- 4.93270271836381
Measured from: -6.89600002765656
to: 1.52799987792969 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 0.0920000076293945
to: 1.09200000762939 [s; relative to TRIGTIME]
Total Fluence
Measured from: -20.8320000171661
to: 9.12799990177155 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.854499 0.698249 0.103959 0.009262
0.046563 0.052673 0.049950 0.044181 [error]
Peak 0.107506 0.112439 0.051163 0.013844
0.009313 0.010317 0.009458 0.007810 [error]
[ fluence units of on-axis counts / fully illuminated detector ]
======================================================================
====== Table of the duration information =============================
Value tstart tstop
T100 29.960 -20.832 9.128
T90 25.988 -19.440 6.548
T50 8.424 -6.896 1.528
Peak 1.000 0.092 1.092
====== 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 -2.642 -0.220 0.203 - - - 2.38e-03 -3.91e-04 3.96e-04 62.100 57
CPL -1.079 -0.722 1.305 19.398 -18.275 6.928 2.53e-02 -2.53e-02 1.66e-01 55.070 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 -2.044 -0.207 0.194 - - - 1.52e-02 -2.23e-03 2.19e-03 51.090 57
CPL -1.314 -0.837 1.191 34.396 -28.934 -34.396 4.37e-02 -4.37e-02 2.21e-01 48.930 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 2.69e-07 2.49e-07 1.60e-07 1.57e-07 7.43e-07 8.35e-07 erg/cm2
90%_error_low -2.80e-08 -2.68e-08 -3.45e-08 -5.57e-08 -8.18e-08 -1.13e-07 erg/cm2
90%_error_hi 2.83e-08 2.63e-08 3.76e-08 7.52e-08 8.54e-08 1.28e-07 erg/cm2
Peak flux PL 1.06e+00 7.72e-01 3.75e-01 2.57e-01 2.33e+00 2.46e+00 ph/cm2/s
90%_error_low -1.42e-01 -8.18e-02 -7.10e-02 -8.11e-02 -2.38e-01 -2.61e-01 ph/cm2/s
90%_error_hi 1.45e-01 8.13e-02 7.37e-02 1.03e-01 2.39e-01 2.63e-01 ph/cm2/s
Fluence CPL 2.55e-07 2.79e-07 1.06e-07 1.04e-08 6.50e-07 6.51e-07 erg/cm2
90%_error_low -3.10e-08 -3.39e-08 -4.38e-08 -8.93e-09 -7.60e-08 -7.68e-08 erg/cm2
90%_error_hi 3.08e-08 3.47e-08 5.15e-08 4.35e-08 8.96e-08 9.50e-08 erg/cm2
Peak flux CPL 1.02e+00 8.40e-01 3.42e-01 7.92e-02 2.26e+00 2.28e+00 ph/cm2/s
90%_error_low -1.52e-01 -1.12e-01 -1.10e-01 -7.92e-02 -2.47e-01 -2.60e-01 ph/cm2/s
90%_error_hi 1.52e-01 1.18e-01 9.03e-02 2.30e-01 2.48e-01 3.05e-01 ph/cm2/s
======================================================================
Image
Pre-slew 15.0-350.0 keV image (Event data)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name 327.9049 -56.6530 0.0132 11.7816 -178.0595 1.7457008 14.562 TRIG_01270788 Foreground time interval of the image: -20.832 9.128 (delta_t = 29.960 [sec]) Background time interval of the image: -60.848 -20.832 (delta_t = 40.016 [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 -20.832 sec. to 9.128 sec. Spectral model in power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -2.64244 ( -0.220313 0.203156 ) Norm@50keV : 2.37771E-03 ( -0.000390756 0.000396471 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared 62.10 using 59 bins. Reduced chi-squared = 1.08947 # Null hypothesis probability of 2.99e-01 with 57 degrees of freedom Photon flux (15-150 keV) in 29.96 sec: 0.511092 ( -0.043704 0.043715 ) ph/cm2/s Energy fluence (15-150 keV) : 7.43415e-07 ( -8.18211e-08 8.54456e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -20.832 sec. to 9.128 sec. Spectral model in the cutoff power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.07937 ( -0.721866 1.30529 ) Epeak [keV] : 19.3976 ( -18.2754 6.92696 ) Norm@50keV : 2.52724E-02 ( -0.0252763 0.165643 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared 55.07 using 59 bins. Reduced chi-squared = 0.983393 # Null hypothesis probability of 5.10e-01 with 56 degrees of freedom Photon flux (15-150 keV) in 29.96 sec: 0.487031 ( -0.044612 0.04514 ) ph/cm2/s Energy fluence (15-150 keV) : 6.49952e-07 ( -7.60316e-08 8.96391e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 0.092 sec. to 1.092 sec. Spectral model in power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -2.04404 ( -0.206551 0.194017 ) Norm@50keV : 1.51864E-02 ( -0.00223061 0.00219207 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared 51.09 using 59 bins. Reduced chi-squared = 0.896316 # Null hypothesis probability of 6.95e-01 with 57 degrees of freedom Photon flux (15-150 keV) in 1 sec: 2.32551 ( -0.23848 0.23854 ) ph/cm2/s Energy fluence (15-150 keV) : 1.40456e-07 ( -1.87309e-08 1.9382e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.092 sec. to 1.092 sec. Spectral model in the cutoff power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.3141 ( -0.837091 1.19106 ) Epeak [keV] : 34.3958 ( -28.9335 -34.3956 ) Norm@50keV : 4.36945E-02 ( -0.0436996 0.220904 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared 48.93 using 59 bins. Reduced chi-squared = 0.87375 # Null hypothesis probability of 7.37e-01 with 56 degrees of freedom Photon flux (15-150 keV) in 1 sec: 2.26476 ( -0.24693 0.24802 ) ph/cm2/s Energy fluence (15-150 keV) : 1.26561e-07 ( -2.24875e-08 2.47638e-08 ) ergs/cm2
Time-resolved spectra
Distribution
T90 vs. Hardness ratio plot
T90 = 25.988 sec. Hardness ratio (energy fluence ratio) = 0.640692995119
S(15-50 keV) vs. S(50-150 keV) plot
S(15-50 keV) = 5.185207e-07 S(50-150 keV) = 2.249007e-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 = -2.084561767038293E-01, IMY = 7.062541447758889E-03
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: -60.848000 -20.832000 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 275.9963 -30.5009 38.3 40.8 -77.5 0.2331 0.3 8.8 H1820-303 284.9004 -24.8379 52.6 38.2 -62.8 -0.0866 -0.2 8.9 HT1900.1-2455 345.8896 -14.8719 2.5 34.8 45.8 1.5057 4.7 ------ UNKNOWN 330.2406 -18.4470 2.8 26.9 19.6 0.8980 4.1 ------ UNKNOWN 96.9967 -78.9781 2.1 52.9 178.8 3.5419 5.5 ------ UNKNOWN 297.6690 3.8331 2.2 54.7 -25.4 3.4731 5.2 ------ UNKNOWN
Pre-slew background subtracted image of 15-350 keV band
Time interval of the image: -20.832000 9.128000 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 275.8403 -30.2839 158.2 41.1 -77.4 0.0412 0.1 6.6 H1820-303 285.0418 -24.9205 278.0 38.0 -62.8 -0.0120 -0.0 0.3 HT1900.1-2455 327.9049 -56.6530 0.8 11.8 -178.1 1.7452 14.6 ------ UNKNOWN
Post-slew image of 15-350 keV band
Time interval of the image: 54.852600 639.352590 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 186.6516 -62.8026 7.2 56.8 -152.8 8.6373 1.6 1.9 GX 301-2 264.8612 -44.3726 4.6 40.3 -92.9 -9.5328 -2.5 6.9 4U 1735-44 284.8764 -25.0123 5.8 44.2 -55.4 -7.2473 -2.0 10.3 HT1900.1-2455 339.5995 -13.5962 2.6 44.0 23.6 6.2636 4.4 ------ UNKNOWN 306.9126 -0.7944 2.5 58.4 -17.7 13.0109 4.7 ------ UNKNOWN 280.9980 -27.0789 2.6 44.4 -61.2 18.7804 4.4 ------ UNKNOWN