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 01:30:07 EST 2014
Host Name: batevent1
Current Working Dir: /local/data/batevent/batevent_reproc/trigger313087
======================================================================
Trigger: 00313087 Segment: 000
BAT Trigger Time: 234214696.128 [s; MET]
Trigger Stop: 234214696.64 [s; MET]
UTC: 2008-06-03T19:38:13.288800 [includes UTCF correction]
Where From?: TDRSS position message
BAT
RA: 176.527531635607 Dec: 68.0759595189382 [deg; J2000]
Catalogged Source?: NO
Point Source?: YES
GRB Indicated?: YES [ by BAT flight software ]
Image S/N Ratio: 10.63
Image Trigger?: NO
Rate S/N Ratio: 19.3649167310371 [ if not an image trigger ]
Image S/N Ratio: 10.63
Analysis Position: [ source = BAT ]
RA: 176.527531635607 Dec: 68.0759595189382 [deg; J2000]
Refined Position: [ source = BAT pre-slew burst ]
RA: 176.551369790955 Dec: 68.0619708322101 [deg; J2000]
{ 11h 46m 12.3s , +68d 03' 43.1" }
+/- 0.748871992018109 [arcmin] (estimated 90% radius based on SNR)
+/- 0.193980388128199 [arcmin] (formal 1-sigma fit error)
SNR: 45.9765215968534
Angular difference between the analysis and refined position is 0.994901 arcmin
Partial Coding Fraction: 1 [ including projection effects ]
Duration
T90: 59.1240000128746 +/- 1.63096534638045
Measured from: 0.944000005722046
to: 60.0680000185966 [s; relative to TRIGTIME]
T50: 45.3440000116825 +/- 1.07059610465852
Measured from: 3.6240000128746
to: 48.9680000245571 [s; relative to TRIGTIME]
Fluence
Peak Flux (peak 1 second)
Measured from: 0.96000000834465
to: 1.96000000834465 [s; relative to TRIGTIME]
Total Fluence
Measured from: -0.11599999666214
to: 68.2560000121593 [s; relative to TRIGTIME]
Band 1 Band 2 Band 3 Band 4
15-25 25-50 50-100 100-350 keV
Total 1.392891 1.776075 1.143370 0.180465
0.039984 0.042232 0.037520 0.032468 [error]
Peak 0.095298 0.152767 0.158416 0.057586
0.005950 0.006854 0.006924 0.005661 [error]
[ fluence units of on-axis counts / fully illuminated detector ]
======================================================================
====== Table of the duration information =============================
Value tstart tstop
T100 68.372 -0.116 68.256
T90 59.124 0.944 60.068
T50 45.344 3.624 48.968
Peak 1.000 0.960 1.960
====== 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 -1.731 -0.061 0.061 - - - 4.09e-03 -1.35e-04 1.35e-04 68.740 57
CPL -1.210 -0.256 0.272 74.941 -10.857 25.782 7.44e-03 -1.86e-03 2.67e-03 56.010 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 -1.098 -0.087 0.087 - - - 3.04e-02 -1.43e-03 1.43e-03 51.930 57
CPL -1.094 -0.086 0.092 9999.210 -9999.210 -9999.210 3.06e-02 -1.38e-03 9.83e-03 51.950 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 4.44e-07 7.09e-07 8.54e-07 2.01e-06 2.58e-06 4.02e-06 erg/cm2
90%_error_low -2.50e-08 -2.35e-08 -3.81e-08 -1.90e-07 -8.86e-08 -2.18e-07 erg/cm2
90%_error_hi 2.55e-08 2.34e-08 3.81e-08 2.03e-07 8.90e-08 2.29e-07 erg/cm2
Peak flux PL 8.54e-01 1.09e+00 1.02e+00 1.68e+00 3.53e+00 4.64e+00 ph/cm2/s
90%_error_low -8.08e-02 -6.22e-02 -5.61e-02 -1.95e-01 -1.69e-01 -2.42e-01 ph/cm2/s
90%_error_hi 8.35e-02 6.17e-02 5.57e-02 2.12e-01 1.69e-01 2.46e-01 ph/cm2/s
Fluence CPL 4.02e-07 7.37e-07 8.68e-07 9.75e-07 2.46e-06 2.98e-06 erg/cm2
90%_error_low -3.12e-08 -2.74e-08 -4.09e-08 -2.65e-07 -1.05e-07 -2.88e-07 erg/cm2
90%_error_hi 3.18e-08 2.77e-08 4.11e-08 3.87e-07 1.05e-07 4.00e-07 erg/cm2
Peak flux CPL 8.52e-01 1.09e+00 1.02e+00 1.67e+00 3.54e+00 4.72e+00 ph/cm2/s
90%_error_low N/A -6.96e-02 -6.10e-02 N/A -2.04e-01 -5.73e-01 ph/cm2/s
90%_error_hi N/A 7.42e-02 7.77e-02 N/A 1.87e-01 1.48e-01 ph/cm2/s
======================================================================
Image
Pre-slew 15.0-350.0 keV image (Event data)
# RAcent DECcent POSerr Theta Phi Peak Cts SNR Name 176.5514 68.0620 0.0042 17.2204 -6.5766 2.0334852 45.977 TRIG_00313087 Foreground time interval of the image: -0.116 10.173 (delta_t = 10.289 [sec]) Background time interval of the image: -30.227 -0.116 (delta_t = 30.111 [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 -0.116 sec. to 68.256 sec. Spectral model in power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.73124 ( -0.0611324 0.0606951 ) Norm@50keV : 4.09093E-03 ( -0.00013497 0.000134618 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 68.74 using 59 PHA bins. # Reduced chi-squared = 1.206 for 57 degrees of freedom # Null hypothesis probability = 1.370554e-01 Photon flux (15-150 keV) in 68.37 sec: 0.549412 ( -0.018451 0.018499 ) ph/cm2/s Energy fluence (15-150 keV) : 2.58419e-06 ( -8.85911e-08 8.89692e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from -0.116 sec. to 68.256 sec. Spectral model in the cutoff power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.21047 ( -0.25618 0.271762 ) Epeak [keV] : 74.9413 ( -10.8568 25.7813 ) Norm@50keV : 7.43716E-03 ( -0.00185624 0.00266603 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 56.01 using 59 PHA bins. # Reduced chi-squared = 1.000 for 56 degrees of freedom # Null hypothesis probability = 4.746309e-01 Photon flux (15-150 keV) in 68.37 sec: 0.528695 ( -0.020703 0.020778 ) ph/cm2/s Energy fluence (15-150 keV) : 2.46437e-06 ( -1.04947e-07 1.05231e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 0.960 sec. to 1.960 sec. Spectral model in power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.0979 ( -0.0867618 0.0872389 ) Norm@50keV : 3.04496E-02 ( -0.00142846 0.00142832 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 51.93 using 59 PHA bins. # Reduced chi-squared = 0.9111 for 57 degrees of freedom # Null hypothesis probability = 6.650848e-01 Photon flux (15-150 keV) in 1 sec: 3.53123 ( -0.16909 0.16926 ) ph/cm2/s Energy fluence (15-150 keV) : 3.18603e-07 ( -1.70803e-08 1.71733e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.960 sec. to 1.960 sec. Spectral model in the cutoff power-law: ------------------------------------------------------------ Parameters : value lower 90% higher 90% Photon index: -1.09382 ( -0.0865545 0.0915793 ) Epeak [keV] : 9999.21 ( -9999.28 -9999.28 ) Norm@50keV : 3.05571E-02 ( -0.00143533 0.00977455 ) ------------------------------------------------------------ #Fit statistic : Chi-Squared = 51.95 using 59 PHA bins. # Reduced chi-squared = 0.9277 for 56 degrees of freedom # Null hypothesis probability = 6.288072e-01 Photon flux (15-150 keV) in 1 sec: 3.53857 ( -0.20352 0.18654 ) ph/cm2/s Energy fluence (15-150 keV) : 3.19463e-07 ( 0 0 ) ergs/cm2
Time-resolved spectra
Distribution
T90 vs. Hardness ratio plot
T90 = 59.124 sec. Hardness ratio (energy fluence ratio) = 1.1782024649
S(15-50 keV) vs. S(50-150 keV) plot
S(15-50 keV) = 1.1385709e-06 S(50-150 keV) = 1.3257862e-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 = 3.079025315625138E-01, IMY = 3.549799085768047E-02
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: -30.227410 -0.116000 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 261.1583 63.2168 2.4 47.7 16.5 0.6510 4.8 ------ UNKNOWN 136.6458 22.5765 2.9 36.6 -152.7 0.2643 4.0 ------ UNKNOWN 6.8847 70.7469 2.9 56.6 -29.1 1.0866 3.9 ------ UNKNOWN 93.7414 54.3869 2.4 41.2 -77.7 0.9653 4.8 ------ UNKNOWN
Pre-slew background subtracted image of 15-350 keV band
Time interval of the image: -0.116000 10.172590 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 176.5514 68.0620 0.3 17.2 -6.6 2.0334 46.0 ------ UNKNOWN 289.9890 73.4202 2.3 49.3 -2.7 0.4454 5.0 ------ UNKNOWN 125.1191 22.6181 2.2 42.4 -138.6 0.4033 5.3 ------ UNKNOWN
Post-slew image of 15-350 keV band
Time interval of the image: 50.972600 483.072000 # RAcent DECcent POSerr Theta Phi PeakCts SNR AngSep Name # [deg] [deg] ['] [deg] [deg] ['] 301.9344 51.5906 2.6 53.7 17.5 21.1896 4.5 ------ UNKNOWN 314.5877 61.5389 4.0 46.9 4.4 5.4091 2.9 ------ UNKNOWN 99.6949 48.5890 3.0 41.2 -99.2 15.6757 3.8 ------ UNKNOWN