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 14:41:39 EDT 2024
Host Name: batproc1
Current Working Dir: /local/data/bat1/alien/Swift_3rdBATcatalog/event/batevent_reproc/trigger1257556
======================================================================
Trigger: 01257556 Segment: 000
BAT Trigger Time: 749523057.152 [s; MET]
Trigger Stop: 749523058.176 [s; MET]
UTC: 2024-10-02T00:50:22.875360 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 140.954765070369 Dec: 39.8542969957009 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 7.55
Image Trigger?: NO
Rate S/N Ratio: 12.0830459735946 [ if not an image trigger ]
Image S/N Ratio: 7.55
Analysis Position: [ source = BAT ]
RA: 140.954765070369 Dec: 39.8542969957009 [deg; J2000]
Refined Position: [ source = BAT pre-slew burst ]
RA: 140.942426622122 Dec: 39.8311057192352 [deg; J2000]
{ 09h 23m 46.2s , +39d 49' 52.0" }
+/- 0.967769763197361 [arcmin] (estimated 90% radius based on SNR)
+/- 0.32162359748843 [arcmin] (formal 1-sigma fit error)
SNR: 31.8745472201793
Angular difference between the analysis and refined position is 1.503097 arcmin
Partial Coding Fraction: 0.6875 [ including projection effects ]
Duration
T90: 43.3039999008179 +/- 4.39230692520438
Measured from: -16.9879999160767
to: 26.3159999847412 [s; relative to TRIGTIME]
T50: 14.4559999704361 +/- 2.00166830305826
Measured from: -7.10399997234344
to: 7.35199999809265 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: -0.275999903678894
to: 0.724000096321106 [s; relative to TRIGTIME]
Total Fluence
Measured from: -21.3359999656677
to: 34.9160000085831 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 1.275678 1.444950 0.790377 0.158888
0.055340 0.057676 0.048100 0.039248 [error]
Peak 0.047282 0.067499 0.070198 0.007890
0.008207 0.008793 0.007541 0.005427 [error]
[ fluence units of on-axis counts / fully illuminated detector ]
======================================================================
====== Table of the duration information =============================
Value tstart tstop
T100 56.252 -21.336 34.916
T90 43.304 -16.988 26.316
T50 14.456 -7.104 7.352
Peak 1.000 -0.276 0.724
====== 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 -1.965 -0.094 0.093 - - - 4.01e-03 -2.24e-04 2.22e-04 58.290 57
CPL -1.507 -0.379 0.416 49.415 -11.894 26.057 7.04e-03 -2.58e-03 4.64e-03 53.990 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 -1.458 -0.200 0.199 - - - 1.33e-02 -1.67e-03 1.67e-03 50.710 57
CPL -0.519 -0.817 0.993 84.647 -20.746 172.160 3.74e-02 -2.19e-02 6.73e-02 46.780 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 4.46e-07 6.19e-07 6.34e-07 1.19e-06 2.08e-06 2.89e-06 erg/cm2
90%_error_low -3.48e-08 -3.04e-08 -4.84e-08 -1.77e-07 -1.12e-07 -2.25e-07 erg/cm2
90%_error_hi 3.56e-08 3.04e-08 4.86e-08 1.97e-07 1.13e-07 2.39e-07 erg/cm2
Peak flux PL 5.24e-01 5.41e-01 3.93e-01 4.60e-01 1.64e+00 1.92e+00 ph/cm2/s
90%_error_low -1.08e-01 -7.44e-02 -5.89e-02 -1.24e-01 -2.11e-01 -2.41e-01 ph/cm2/s
90%_error_hi 1.15e-01 7.36e-02 5.83e-02 1.47e-01 2.12e-01 2.42e-01 ph/cm2/s
Fluence CPL 4.18e-07 6.47e-07 6.36e-07 5.91e-07 2.00e-06 2.29e-06 erg/cm2
90%_error_low -4.14e-08 -3.84e-08 -5.21e-08 -2.43e-07 -1.29e-07 -2.80e-07 erg/cm2
90%_error_hi 4.20e-08 3.91e-08 5.19e-08 4.50e-07 1.30e-07 4.63e-07 erg/cm2
Peak flux CPL 4.30e-01 5.83e-01 4.38e-01 2.11e-01 1.59e+00 1.66e+00 ph/cm2/s
90%_error_low -1.34e-01 -8.66e-02 -7.22e-02 -1.03e-01 -2.17e-01 -2.48e-01 ph/cm2/s
90%_error_hi 1.40e-01 8.89e-02 7.48e-02 2.08e-01 2.17e-01 2.82e-01 ph/cm2/s
======================================================================
Image
Pre-slew 15.0-350.0 keV image (Event data)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name 140.9424 39.8311 0.0060 32.6096 -28.8195 3.3524248 31.875 TRIG_01257556 Foreground time interval of the image: -21.336 17.349 (delta_t = 38.685 [sec]) Background time interval of the image: -239.152 -21.336 (delta_t = 217.816 [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 -21.336 sec. to 34.916 sec. Spectral model in power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.96459 ( -0.0943323 0.0925114 ) Norm@50keV : 4.01006E-03 ( -0.000224116 0.000222135 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared 58.29 using 59 bins. Reduced chi-squared = 1.02263 # Null hypothesis probability of 4.28e-01 with 57 degrees of freedom Photon flux (15-150 keV) in 56.25 sec: 0.591965 ( -0.030262 0.030325 ) ph/cm2/s Energy fluence (15-150 keV) : 2.07717e-06 ( -1.119e-07 1.12619e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -21.336 sec. to 34.916 sec. Spectral model in the cutoff power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.50727 ( -0.379351 0.416161 ) Epeak [keV] : 49.4150 ( -11.894 26.057 ) Norm@50keV : 7.04395E-03 ( -0.00257999 0.00464289 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared 53.99 using 59 bins. Reduced chi-squared = 0.964107 # Null hypothesis probability of 5.51e-01 with 56 degrees of freedom Photon flux (15-150 keV) in 56.25 sec: 0.576679 ( -0.032622 0.032708 ) ph/cm2/s Energy fluence (15-150 keV) : 1.99569e-06 ( -1.29212e-07 1.30112e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from -0.276 sec. to 0.724 sec. Spectral model in power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.45841 ( -0.199964 0.198566 ) Norm@50keV : 1.32513E-02 ( -0.00167036 0.00166725 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared 50.71 using 59 bins. Reduced chi-squared = 0.889649 # Null hypothesis probability of 7.08e-01 with 57 degrees of freedom Photon flux (15-150 keV) in 1 sec: 1.63651 ( -0.21127 0.21175 ) ph/cm2/s Energy fluence (15-150 keV) : 1.26628e-07 ( -1.7071e-08 1.71591e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.276 sec. to 0.724 sec. Spectral model in the cutoff power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -0.519422 ( -0.817386 0.9931 ) Epeak [keV] : 84.6473 ( -20.7457 172.16 ) Norm@50keV : 3.73522E-02 ( -0.0218508 0.0672775 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared 46.78 using 59 bins. Reduced chi-squared = 0.835357 # Null hypothesis probability of 8.05e-01 with 56 degrees of freedom Photon flux (15-150 keV) in 1 sec: 1.58837 ( -0.21742 0.21685 ) ph/cm2/s Energy fluence (15-150 keV) : 1.22659e-07 ( -1.75016e-08 1.76224e-08 ) ergs/cm2
Time-resolved spectra
Distribution
T90 vs. Hardness ratio plot
T90 = 43.304 sec. Hardness ratio (energy fluence ratio) = 1.0248959624
S(15-50 keV) vs. S(50-150 keV) plot
S(15-50 keV) = 1.0649934e-06 S(50-150 keV) = 1.0122056e-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 = 5.605232606910161E-01, IMY = 3.083993593445276E-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: -239.152000 -21.336000 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 254.3938 35.2633 4.6 54.4 -176.4 -2.1376 -2.5 5.7 Her X-1 251.1791 30.6222 2.3 57.3 -170.9 6.0928 5.0 ------ UNKNOWN
Pre-slew background subtracted image of 15-350 keV band
Time interval of the image: -21.336000 17.348630 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 254.4681 35.4864 5.4 54.3 -176.6 -0.5081 -2.1 8.6 Her X-1 238.1610 38.8153 2.6 45.0 -163.8 0.6217 4.4 ------ UNKNOWN 140.9424 39.8311 0.4 32.6 -28.8 3.3523 31.9 ------ UNKNOWN
Post-slew image of 15-350 keV band
Time interval of the image: 94.148580 326.348610 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 96.5130 33.3376 2.3 35.9 61.0 3.6413 5.0 ------ UNKNOWN 182.6625 74.4120 2.3 39.5 163.4 2.6198 4.9 ------ UNKNOWN 130.7740 36.9354 1.9 8.5 40.3 1.6836 6.0 ------ UNKNOWN