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 16:39:19 EST 2014
Host Name: batevent1
Current Working Dir: /local/data/batevent/batevent_reproc/trigger208870
======================================================================
Trigger: 00208870 Segment: 000
BAT Trigger Time: 168659593.408 [s; MET]
Trigger Stop: 168659594.432 [s; MET]
UTC: 2006-05-07T01:53:12.230320 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 89.9718765738037 Dec: 75.2369661619308 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 7.19
Image Trigger?: NO
Rate S/N Ratio: 13.9283882771841 [ if not an image trigger ]
Image S/N Ratio: 7.19
Analysis Position: [ source = BAT ]
RA: 89.9718765738037 Dec: 75.2369661619308 [deg; J2000]
Refined Position: [ source = BAT pre-slew burst ]
RA: 89.9170795434187 Dec: 75.2445670373931 [deg; J2000]
{ 05h 59m 40.1s , +75d 14' 40.4" }
+/- 1.16688567696737 [arcmin] (estimated 90% radius based on SNR)
+/- 0.356029995276097 [arcmin] (formal 1-sigma fit error)
SNR: 24.3985295294464
Angular difference between the analysis and refined position is 0.953706 arcmin
Partial Coding Fraction: 0.328125 [ including projection effects ]
Duration
T90: 183.307999998331 +/- 6.56904864953299
Measured from: -3.47599998116493
to: 179.832000017166 [s; relative to TRIGTIME]
T50: 114.351999998093 +/- 7.59182822267909
Measured from: 13.9080000221729
to: 128.260000020266 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 1.24400001764297
to: 2.24400001764297 [s; relative to TRIGTIME]
Total Fluence
Measured from: -11.0239999890327
to: 192.351999998093 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 2.561571 2.946703 1.841847 0.393402
0.107108 0.113480 0.099974 0.084487 [error]
Peak 0.048339 0.051640 0.042969 0.005518
0.008201 0.008814 0.008155 0.006240 [error]
[ fluence units of on-axis counts / fully illuminated detector ]
======================================================================
====== Table of the duration information =============================
Value tstart tstop
T100 203.376 -11.024 192.352
T90 183.308 -3.476 179.832
T50 114.352 13.908 128.260
Peak 1.000 1.244 2.244
====== 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 -1.807 -0.086 0.085 - - - 2.41e-03 -1.20e-04 1.20e-04 56.540 57
CPL -1.445 -0.335 0.364 72.423 -16.446 216.286 3.74e-03 -1.21e-03 2.02e-03 53.110 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 -1.664 -0.286 0.271 - - - 9.83e-03 -1.80e-03 1.76e-03 52.780 57
CPL -0.937 -0.602 1.477 68.114 -35.691 -68.114 2.43e-02 -2.43e-02 1.24e-01 51.610 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 8.37e-07 1.28e-06 1.46e-06 3.18e-06 4.52e-06 6.75e-06 erg/cm2
90%_error_low -6.31e-08 -5.95e-08 -9.86e-08 -4.31e-07 -2.29e-07 -5.20e-07 erg/cm2
90%_error_hi 6.45e-08 5.94e-08 9.87e-08 4.75e-07 2.31e-07 5.53e-07 erg/cm2
Peak flux PL 4.73e-01 4.32e-01 2.73e-01 2.64e-01 1.29e+00 1.44e+00 ph/cm2/s
90%_error_low -1.15e-01 -7.18e-02 -6.33e-02 -1.03e-01 -2.12e-01 -2.41e-01 ph/cm2/s
90%_error_hi 1.21e-01 7.16e-02 6.29e-02 1.34e-01 2.12e-01 2.43e-01 ph/cm2/s
Fluence CPL 8.53e-07 1.16e-06 1.22e-06 2.83e-06 3.99e-06 5.99e-06 erg/cm2
90%_error_low -7.03e-08 -1.09e-07 -1.09e-07 -1.70e-06 -3.91e-07 -4.51e-07 erg/cm2
90%_error_hi 5.40e-08 5.04e-08 8.85e-08 2.13e-07 1.47e-07 3.88e-07 erg/cm2
Peak flux CPL 4.30e-01 4.71e-01 2.85e-01 1.17e-01 1.26e+00 1.30e+00 ph/cm2/s
90%_error_low -1.38e-01 -9.26e-02 -7.14e-02 -1.17e-01 -2.17e-01 -2.42e-01 ph/cm2/s
90%_error_hi 1.38e-01 9.79e-02 7.28e-02 1.88e-01 2.16e-01 3.10e-01 ph/cm2/s
======================================================================
Image
Pre-slew 15.0-350.0 keV image (Event data)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name 89.9171 75.2446 0.0079 32.6125 -84.7124 6.7780321 24.399 TRIG_00208870 Foreground time interval of the image: -11.024 171.693 (delta_t = 182.717 [sec]) Background time interval of the image: -239.408 -11.024 (delta_t = 228.384 [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 -11.024 sec. to 192.352 sec. Spectral model in power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.80731 ( -0.086164 0.0850524 ) Norm@50keV : 2.41326E-03 ( -0.000120432 0.000119689 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 56.54 using 59 PHA bins. # Reduced chi-squared = 0.9920 for 57 degrees of freedom # Null hypothesis probability = 4.921891e-01 Photon flux (15-150 keV) in 203.4 sec: 0.333506 ( -0.015893 0.015921 ) ph/cm2/s Energy fluence (15-150 keV) : 4.51847e-06 ( -2.29224e-07 2.30517e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -11.024 sec. to 192.352 sec. Spectral model in the cutoff power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.44502 ( -0.334836 0.364359 ) Epeak [keV] : 72.4230 ( -16.446 216.286 ) Norm@50keV : 3.73635E-03 ( -0.00121314 0.00201607 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 53.11 using 59 PHA bins. # Reduced chi-squared = 0.9483 for 56 degrees of freedom # Null hypothesis probability = 5.851219e-01 Photon flux (15-150 keV) in 203.4 sec: 0.326674 ( -0.017057 0.017061 ) ph/cm2/s Energy fluence (15-150 keV) : 3.98511e-06 ( -3.90512e-07 1.46511e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 1.244 sec. to 2.244 sec. Spectral model in power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.66395 ( -0.285897 0.270811 ) Norm@50keV : 9.82698E-03 ( -0.00179843 0.00175761 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 52.78 using 59 PHA bins. # Reduced chi-squared = 0.9259 for 57 degrees of freedom # Null hypothesis probability = 6.341612e-01 Photon flux (15-150 keV) in 1 sec: 1.28918 ( -0.21182 0.21189 ) ph/cm2/s Energy fluence (15-150 keV) : 9.1283e-08 ( -1.74195e-08 1.7738e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 1.244 sec. to 2.244 sec. Spectral model in the cutoff power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -0.937324 ( -0.601563 1.47665 ) Epeak [keV] : 68.1139 ( -35.6903 -68.1138 ) Norm@50keV : 2.42502E-02 ( -0.0242503 0.123548 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 51.61 using 59 PHA bins. # Reduced chi-squared = 0.9217 for 56 degrees of freedom # Null hypothesis probability = 6.414745e-01 Photon flux (15-150 keV) in 1 sec: 1.26370 ( -0.21703 0.2162 ) ph/cm2/s Energy fluence (15-150 keV) : 8.66583e-08 ( -1.85923e-08 1.91915e-08 ) ergs/cm2
Time-resolved spectra
Distribution
T90 vs. Hardness ratio plot
T90 = 183.308 sec. Hardness ratio (energy fluence ratio) = 1.14293160967
S(15-50 keV) vs. S(50-150 keV) plot
S(15-50 keV) = 2.1127274e-06 S(50-150 keV) = 2.4057355e-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 = 5.896374236559877E-02, IMY = 6.371114541575648E-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: -239.408000 -11.024000 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 254.4108 35.3162 3.4 47.8 36.5 1.8523 3.4 2.8 Her X-1 160.9200 29.3155 2.2 38.3 165.2 1.0817 5.2 ------ UNKNOWN
Pre-slew background subtracted image of 15-350 keV band
Time interval of the image: -11.024000 171.692590 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 254.3551 35.3002 5.8 47.8 36.6 -1.1482 -2.0 5.6 Her X-1 321.7722 67.1972 2.4 45.4 -33.2 1.5418 4.9 ------ UNKNOWN 89.9171 75.2446 0.5 32.6 -84.7 6.7775 24.4 ------ UNKNOWN
Post-slew image of 15-350 keV band
Time interval of the image: 241.692590 962.618200 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 299.5852 35.2085 0.4 37.9 53.2 31.8157 32.6 0.5 Cyg X-1 308.2252 40.8226 8.1 29.3 49.8 0.8026 1.4 9.4 Cyg X-3 325.9958 38.3224 78.4 24.0 20.8 -0.0584 -0.1 8.3 Cyg X-2 306.7455 69.8740 2.2 19.4 121.2 2.0881 5.1 ------ UNKNOWN 51.8479 41.5999 3.1 43.8 -116.1 7.0435 3.7 ------ UNKNOWN