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: Mon Jan 20 04:54:09 EST 2014
Host Name: batevent1
Current Working Dir: /local/data/batevent/batevent_reproc/trigger302506
======================================================================
Trigger: 00302506 Segment: 000
BAT Trigger Time: 223890954.304 [s; MET]
Trigger Stop: 223890955.328 [s; MET]
UTC: 2008-02-05T07:55:51.751640 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 98.2192547486492 Dec: 62.7686859637972 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 8.53
Image Trigger?: NO
Rate S/N Ratio: 15.0996688705415 [ if not an image trigger ]
Image S/N Ratio: 8.53
Analysis Position: [ source = BAT ]
RA: 98.2192547486492 Dec: 62.7686859637972 [deg; J2000]
Refined Position: [ source = BAT pre-slew burst ]
RA: 98.2610086338524 Dec: 62.7784563195902 [deg; J2000]
{ 06h 33m 02.6s , +62d 46' 42.4" }
+/- 1.50929342618172 [arcmin] (estimated 90% radius based on SNR)
+/- 0.739362038112901 [arcmin] (formal 1-sigma fit error)
SNR: 16.8938023144618
Angular difference between the analysis and refined position is 1.287380 arcmin
Partial Coding Fraction: 0.5234375 [ including projection effects ]
Duration
T90: 106.296000003815 +/- 4.93487059748703
Measured from: -5.49199998378754
to: 100.804000020027 [s; relative to TRIGTIME]
T50: 84.7360000014305 +/- 4.65087088671953
Measured from: 4.96000000834465
to: 89.6960000097752 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 0.224000006914139
to: 1.22400000691414 [s; relative to TRIGTIME]
Total Fluence
Measured from: -10.0879999995232
to: 105.384000003338 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 1.408370 1.443025 0.789049 0.104495
0.066264 0.068437 0.059438 0.050288 [error]
Peak 0.049252 0.063070 0.029516 0.010314
0.008045 0.008378 0.007154 0.005717 [error]
[ fluence units of on-axis counts / fully illuminated detector ]
======================================================================
====== Table of the duration information =============================
Value tstart tstop
T100 115.472 -10.088 105.384
T90 106.296 -5.492 100.804
T50 84.736 4.960 89.696
Peak 1.000 0.224 1.224
====== 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 -1.959 -0.115 0.112 - - - 1.91e-03 -1.29e-04 1.27e-04 46.110 57
CPL -1.826 -0.402 0.453 58.793 -48.313 -58.793 2.26e-03 -8.50e-04 1.68e-03 45.810 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 -1.950 -0.306 0.283 - - - 9.57e-03 -1.86e-03 1.78e-03 55.660 57
CPL -1.960 -0.297 0.295 9999.360 N/A N/A 9.51e-03 N/A N/A 55.660 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 4.34e-07 6.04e-07 6.21e-07 1.17e-06 2.03e-06 2.83e-06 erg/cm2
90%_error_low -3.88e-08 -3.40e-08 -5.84e-08 -2.13e-07 -1.31e-07 -2.71e-07 erg/cm2
90%_error_hi 3.98e-08 3.40e-08 5.88e-08 2.43e-07 1.33e-07 2.94e-07 erg/cm2
Peak flux PL 6.08e-01 4.69e-01 2.43e-01 1.81e-01 1.40e+00 1.50e+00 ph/cm2/s
90%_error_low -1.36e-01 -7.23e-02 -6.10e-02 -7.53e-02 -2.18e-01 -2.33e-01 ph/cm2/s
90%_error_hi 1.42e-01 7.23e-02 6.14e-02 1.02e-01 2.18e-01 2.33e-01 ph/cm2/s
Fluence CPL 4.27e-07 6.12e-07 6.21e-07 9.22e-07 2.00e-06 2.58e-06 erg/cm2
90%_error_low -4.53e-08 -6.91e-08 -6.01e-08 -4.67e-07 -1.57e-07 -5.02e-07 erg/cm2
90%_error_hi 4.58e-08 4.31e-08 6.00e-08 5.28e-07 1.32e-07 5.64e-07 erg/cm2
Peak flux CPL 6.09e-01 4.68e-01 2.43e-01 1.80e-01 1.40e+00 1.51e+00 ph/cm2/s
90%_error_low -1.38e-01 -7.10e-02 -6.09e-02 -5.16e-02 -1.11e-01 -1.73e-01 ph/cm2/s
90%_error_hi 1.46e-01 1.28e-01 6.20e-02 1.38e-01 2.17e-01 2.25e-01 ph/cm2/s
======================================================================
Image
Pre-slew 15.0-350.0 keV image (Event data)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name 98.2610 62.7785 0.0115 38.4449 -144.9738 1.2312217 16.894 TRIG_00302506 Foreground time interval of the image: -10.088 16.397 (delta_t = 26.485 [sec]) Background time interval of the image: -179.203 -10.088 (delta_t = 169.115 [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 -10.088 sec. to 105.384 sec. Spectral model in power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.9593 ( -0.114722 0.111876 ) Norm@50keV : 1.91061E-03 ( -0.000128967 0.000127281 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 46.11 using 59 PHA bins. # Reduced chi-squared = 0.8089 for 57 degrees of freedom # Null hypothesis probability = 8.485187e-01 Photon flux (15-150 keV) in 115.5 sec: 0.281378 ( -0.016301 0.016341 ) ph/cm2/s Energy fluence (15-150 keV) : 2.03176e-06 ( -1.31287e-07 1.32611e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -10.088 sec. to 105.384 sec. Spectral model in the cutoff power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.82636 ( -0.401953 0.452559 ) Epeak [keV] : 58.7929 ( -48.3129 -58.7929 ) Norm@50keV : 2.25632E-03 ( -0.00085039 0.00167755 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 45.81 using 59 PHA bins. # Reduced chi-squared = 0.8181 for 56 degrees of freedom # Null hypothesis probability = 8.324469e-01 Photon flux (15-150 keV) in 115.5 sec: 0.279148 ( -0.017687 0.017664 ) ph/cm2/s Energy fluence (15-150 keV) : 2.00393e-06 ( -1.56648e-07 1.31537e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 0.224 sec. to 1.224 sec. Spectral model in power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.94974 ( -0.305583 0.282846 ) Norm@50keV : 9.56896E-03 ( -0.00185643 0.00178415 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 55.66 using 59 PHA bins. # Reduced chi-squared = 0.9764 for 57 degrees of freedom # Null hypothesis probability = 5.256324e-01 Photon flux (15-150 keV) in 1 sec: 1.40327 ( -0.21767 0.2178 ) ph/cm2/s Energy fluence (15-150 keV) : 8.80745e-08 ( -1.6065e-08 1.64192e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.224 sec. to 1.224 sec. Spectral model in the cutoff power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.95996 ( -0.300406 0.29148 ) Epeak [keV] : 9999.36 ( ) Norm@50keV : 9.51148E-03 ( ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 55.66 using 59 PHA bins. # Reduced chi-squared = 0.9939 for 56 degrees of freedom # Null hypothesis probability = 4.877689e-01 Photon flux (15-150 keV) in 1 sec: 1.40443 ( -0.11116 0.21744 ) ph/cm2/s Energy fluence (15-150 keV) : 8.82206e-08 ( -1.06834e-08 1.30142e-08 ) ergs/cm2
Time-resolved spectra
Distribution
T90 vs. Hardness ratio plot
T90 = 106.296 sec. Hardness ratio (energy fluence ratio) = 1.02865548302
S(15-50 keV) vs. S(50-150 keV) plot
S(15-50 keV) = 1.0386144e-06 S(50-150 keV) = 9.931606e-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 = -6.500885653266495E-01, IMY = 4.556405148097904E-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: -179.203410 -10.088000 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 83.6277 22.0177 0.8 48.4 153.8 7.0778 13.6 0.4 Crab 80.5388 27.9672 2.3 48.6 162.6 2.2441 4.9 ------ UNKNOWN 171.8028 60.9128 3.0 35.6 -89.1 1.2548 3.8 ------ UNKNOWN
Pre-slew background subtracted image of 15-350 keV band
Time interval of the image: -10.088000 16.396600 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 83.6026 21.9067 3.9 48.5 153.7 -0.4979 -2.9 6.7 Crab 98.2610 62.7785 0.7 38.4 -145.0 1.2309 16.9 ------ UNKNOWN
Post-slew image of 15-350 keV band
Time interval of the image: 89.396590 962.746900 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 83.6412 22.0093 0.4 42.0 160.3 35.5781 28.6 0.5 Crab 178.9273 57.1384 3.4 38.1 20.1 2.7101 3.4 ------ UNKNOWN 196.8742 61.3466 2.7 41.6 5.3 3.5941 4.3 ------ UNKNOWN 245.7727 59.8381 2.8 54.9 -20.9 7.8687 4.1 ------ UNKNOWN 44.8089 27.9060 3.3 48.9 -149.9 4.2650 3.6 ------ UNKNOWN