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 v2.46
Process Start Time: Wed Jan 22 19:00:01 EST 2014
Host Name: batevent1
Current Working Dir: /local/data/batevent/batevent_reproc/trigger176818
======================================================================
Trigger: 00176818 Segment: 000
BAT Trigger Time: 158646187.072 [s; MET]
Trigger Stop: 158646187.584 [s; MET]
UTC: 2006-01-11T04:23:06.123420 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 276.212529459245 Dec: 37.6021981979871 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 7.47
Image Trigger?: NO
Rate S/N Ratio: 13.490737563232 [ if not an image trigger ]
Image S/N Ratio: 7.47
Analysis Position: [ source = BAT ]
RA: 276.212529459245 Dec: 37.6021981979871 [deg; J2000]
Refined Position: [ source = BAT pre-slew burst ]
RA: 276.195122916218 Dec: 37.6025187890992 [deg; J2000]
{ 18h 24m 46.8s , +37d 36' 09.1" }
+/- 0.745420441804269 [arcmin] (estimated 90% radius based on SNR)
+/- 0.175819634076369 [arcmin] (formal 1-sigma fit error)
SNR: 46.2809472804975
Angular difference between the analysis and refined position is 0.827659 arcmin
Partial Coding Fraction: 0.9765625 [ including projection effects ]
Duration
T90: 13.2120000123978 +/- 1.16562085145432
Measured from: 0.416000008583069
to: 13.6280000209808 [s; relative to TRIGTIME]
T50: 5.8759999871254 +/- 0.370621123835605
Measured from: 3.09600001573563
to: 8.97200000286102 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 4.3120000064373
to: 5.3120000064373 [s; relative to TRIGTIME]
Total Fluence
Measured from: -0.65200001001358
to: 17.5760000050068 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 0.580907 0.862868 0.572613 0.085311
0.022678 0.024311 0.021082 0.017420 [error]
Peak 0.047394 0.088599 0.067138 0.015762
0.005592 0.006138 0.005385 0.004256 [error]
[ fluence units of on-axis counts / fully illuminated detector ]
======================================================================
====== Table of the duration information =============================
Value tstart tstop
T100 18.228 -0.652 17.576
T90 13.212 0.416 13.628
T50 5.876 3.096 8.972
Peak 1.000 4.312 5.312
====== 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: CPL)
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 -1.621 -0.065 0.064 - - - 7.50e-03 -2.77e-04 2.77e-04 63.410 57
CPL -0.882 -0.283 0.302 73.880 -9.112 16.935 1.78e-02 -4.91e-03 7.38e-03 41.340 56
=== 1-s peak spectral analysis ===
(Best model with acceptable fit: CPL)
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 -1.375 -0.130 0.130 - - - 1.46e-02 -1.16e-03 1.16e-03 53.850 57
CPL -0.522 -0.570 0.662 86.007 -18.969 71.903 3.96e-02 -1.90e-02 4.49e-02 46.900 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 1.96e-07 3.34e-07 4.34e-07 1.14e-06 1.28e-06 2.11e-06 erg/cm2
90%_error_low -1.21e-08 -1.26e-08 -2.11e-08 -1.15e-07 -5.02e-08 -1.32e-07 erg/cm2
90%_error_hi 1.23e-08 1.26e-08 2.11e-08 1.23e-07 5.04e-08 1.38e-07 erg/cm2
Peak flux PL 5.32e-01 5.77e-01 4.44e-01 5.61e-01 1.76e+00 2.11e+00 ph/cm2/s
90%_error_low -7.01e-02 -4.90e-02 -4.34e-02 -1.03e-01 -1.40e-01 -1.72e-01 ph/cm2/s
90%_error_hi 7.28e-02 4.87e-02 4.31e-02 1.17e-01 1.40e-01 1.74e-01 ph/cm2/s
Fluence CPL 1.72e-07 3.57e-07 4.46e-07 4.22e-07 1.20e-06 1.40e-06 erg/cm2
90%_error_low -1.45e-08 -1.53e-08 -2.33e-08 -1.18e-07 -5.76e-08 -1.31e-07 erg/cm2
90%_error_hi 1.48e-08 1.55e-08 2.34e-08 1.72e-07 5.79e-08 1.78e-07 erg/cm2
Peak flux CPL 4.59e-01 6.26e-01 4.74e-01 2.34e-01 1.71e+00 1.79e+00 ph/cm2/s
90%_error_low -8.39e-02 -6.02e-02 -5.00e-02 -1.00e-01 -1.45e-01 -1.79e-01 ph/cm2/s
90%_error_hi 8.61e-02 6.21e-02 5.09e-02 1.76e-01 1.45e-01 2.14e-01 ph/cm2/s
======================================================================
Image
Pre-slew 15.0-350.0 keV image (Event data)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name 276.1951 37.6025 0.0042 17.9957 -34.0834 1.7417863 46.281 TRIG_00176818 Foreground time interval of the image: -0.652 10.029 (delta_t = 10.681 [sec]) Background time interval of the image: -299.072 -0.652 (delta_t = 298.420 [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 -0.652 sec. to 17.576 sec. Spectral model in power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.62126 ( -0.0647158 0.0643743 ) Norm@50keV : 7.50084E-03 ( -0.000277474 0.000276868 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 63.41 using 59 PHA bins. # Reduced chi-squared = 1.112 for 57 degrees of freedom # Null hypothesis probability = 2.607037e-01 Photon flux (15-150 keV) in 18.23 sec: 0.970386 ( -0.036229 0.036284 ) ph/cm2/s Energy fluence (15-150 keV) : 1.27581e-06 ( -5.02178e-08 5.04114e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.652 sec. to 17.576 sec. Spectral model in the cutoff power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -0.881578 ( -0.282745 0.302151 ) Epeak [keV] : 73.8797 ( -9.11199 16.9346 ) Norm@50keV : 1.78008E-02 ( -0.00491232 0.00738222 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 41.34 using 59 PHA bins. # Reduced chi-squared = 0.7381 for 56 degrees of freedom # Null hypothesis probability = 9.285129e-01 Photon flux (15-150 keV) in 18.23 sec: 0.929450 ( -0.038988 0.039053 ) ph/cm2/s Energy fluence (15-150 keV) : 1.19695e-06 ( -5.75776e-08 5.78824e-08 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 4.312 sec. to 5.312 sec. Spectral model in power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.37543 ( -0.130281 0.129848 ) Norm@50keV : 1.45642E-02 ( -0.00116344 0.00116075 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 53.85 using 59 PHA bins. # Reduced chi-squared = 0.9446 for 57 degrees of freedom # Null hypothesis probability = 5.941915e-01 Photon flux (15-150 keV) in 1 sec: 1.76404 ( -0.14025 0.14035 ) ph/cm2/s Energy fluence (15-150 keV) : 1.41472e-07 ( -1.25491e-08 1.2659e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 4.312 sec. to 5.312 sec. Spectral model in the cutoff power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -0.522309 ( -0.569944 0.661791 ) Epeak [keV] : 86.0075 ( -18.9695 71.902 ) Norm@50keV : 3.95962E-02 ( -0.0189837 0.0449301 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 46.90 using 59 PHA bins. # Reduced chi-squared = 0.8375 for 56 degrees of freedom # Null hypothesis probability = 8.017045e-01 Photon flux (15-150 keV) in 1 sec: 1.71031 ( -0.14524 0.14504 ) ph/cm2/s Energy fluence (15-150 keV) : 1.32749e-07 ( -1.3896e-08 1.40016e-08 ) ergs/cm2
Time-resolved spectra
Distribution
T90 vs. Hardness ratio plot
T90 = 13.212 sec. Hardness ratio (energy fluence ratio) = 1.24956798927
S(15-50 keV) vs. S(50-150 keV) plot
S(15-50 keV) = 5.286764e-07 S(50-150 keV) = 6.682792e-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 = 2.690370798467176E-01, IMY = 1.820379872454307E-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: -299.072000 -0.652000 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 254.3310 35.1879 0.0 34.0 -16.1 -0.3124 -1.2 11.2 Her X-1 288.8336 10.9480 1.8 36.2 -88.1 3.7315 6.5 2.1 GRS 1915+105 299.5871 35.1991 0.2 11.3 -111.5 13.9365 68.6 0.2 Cyg X-1 308.0550 40.8911 2.2 9.4 -160.9 1.0635 5.2 4.5 Cyg X-3 326.1285 38.4589 4.0 22.4 177.6 0.6274 2.9 8.5 Cyg X-2 317.3283 32.1986 2.5 20.8 -156.7 0.9655 4.6 ------ UNKNOWN 268.4826 11.9729 2.7 42.2 -57.7 2.8238 4.3 ------ UNKNOWN 324.7872 0.3522 2.8 51.9 -138.3 4.8418 4.1 ------ UNKNOWN
Pre-slew background subtracted image of 15-350 keV band
Time interval of the image: -0.652000 10.028600 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 254.3898 35.1992 25.7 34.0 -16.1 -0.0205 -0.4 9.2 Her X-1 288.9143 10.8850 11.4 36.2 -88.3 -0.0891 -1.0 7.7 GRS 1915+105 299.7305 35.3277 16.2 11.2 -112.2 0.0267 0.7 10.2 Cyg X-1 308.1111 41.0295 3.7 9.3 -161.7 0.1152 3.1 4.6 Cyg X-3 326.2214 38.3440 6.3 22.6 177.8 -0.0740 -1.8 2.7 Cyg X-2 276.1951 37.6025 0.2 18.0 -34.1 1.7418 46.3 ------ UNKNOWN 242.8969 22.5658 2.2 49.7 -21.9 0.4308 5.2 ------ UNKNOWN 236.2190 15.9283 1.9 58.8 -22.4 1.4478 6.1 ------ UNKNOWN
Post-slew image of 15-350 keV band
Time interval of the image: 54.828600 302.991400 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 254.4621 35.3507 92.4 17.6 16.5 -0.0216 -0.1 0.5 Her X-1 268.2952 -1.3360 6.3 39.6 -60.3 0.8829 1.8 8.2 SW J1753.5-0127 288.7988 10.9677 1.0 28.9 -99.0 3.4256 12.1 1.3 GRS 1915+105 299.5860 35.1937 0.2 18.9 -162.5 11.2391 66.4 0.5 Cyg X-1 308.1127 40.9461 3.2 24.8 179.5 0.7006 3.7 0.4 Cyg X-3 325.9715 38.2417 7.6 38.8 -179.5 -0.4081 -1.5 10.6 Cyg X-2 251.2310 51.9083 2.7 22.6 64.5 0.9082 4.3 ------ UNKNOWN 249.3029 36.5424 2.2 21.4 22.7 0.9277 5.2 ------ UNKNOWN 334.2533 16.9821 2.5 54.6 -157.3 2.9918 4.6 ------ UNKNOWN 270.1099 -5.6797 2.4 43.7 -64.0 3.8503 4.7 ------ UNKNOWN